diff --git a/.clang-tidy b/.clang-tidy
index 6a24cbc8d3..5a1ba7c321 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -45,52 +45,20 @@ Checks: "-*,
   llvm-namespace-comment,
 
   misc-*,
-  -misc-anonymous-namespace-in-header,
-  -misc-confusable-identifiers,
-  -misc-coroutine-hostile-raii,
-  -misc-misleading-bidirectional,
-  -misc-misleading-identifier,
   -misc-multiple-inheritance,
-  -misc-new-delete-overloads,
   -misc-no-recursion,
-  -misc-non-copyable-objects,
   -misc-non-private-member-variables-in-classes,
   -misc-override-with-different-visibility,
-  -misc-predictable-rand,
-  -misc-unconventional-assign-operator,
-  -misc-uniqueptr-reset-release,
   -misc-unused-parameters,
   -misc-use-anonymous-namespace,
   -misc-use-internal-linkage,
 
   modernize-*,
-  -modernize-avoid-bind,
   -modernize-avoid-c-arrays,
   -modernize-avoid-c-style-cast,
-  -modernize-avoid-setjmp-longjmp,
-  -modernize-avoid-variadic-functions,
-  -modernize-deprecated-ios-base-aliases,
-  -modernize-loop-convert,
-  -modernize-macro-to-enum,
-  -modernize-min-max-use-initializer-list,
-  -modernize-raw-string-literal,
-  -modernize-redundant-void-arg,
-  -modernize-replace-auto-ptr,
-  -modernize-replace-disallow-copy-and-assign-macro,
-  -modernize-replace-random-shuffle,
   -modernize-return-braced-init-list,
-  -modernize-shrink-to-fit,
-  -modernize-use-bool-literals,
-  -modernize-use-constraints,
-  -modernize-use-default-member-init,
   -modernize-use-integer-sign-comparison,
-  -modernize-use-noexcept,
-  -modernize-use-nullptr,
-  -modernize-use-std-format,
-  -modernize-use-std-print,
   -modernize-use-trailing-return-type,
-  -modernize-use-transparent-functors,
-  -modernize-use-uncaught-exceptions,
 
   performance-*,
   -performance-avoid-endl,
diff --git a/.github/scripts/levelization/results/ordering.txt b/.github/scripts/levelization/results/ordering.txt
index 5cc49dd2f5..aee6f4c579 100644
--- a/.github/scripts/levelization/results/ordering.txt
+++ b/.github/scripts/levelization/results/ordering.txt
@@ -72,7 +72,6 @@ test.app > xrpl.server
 test.app > xrpl.shamap
 test.app > xrpl.tx
 test.basics > test.jtx
-test.basics > test.unit_test
 test.basics > xrpl.basics
 test.basics > xrpl.core
 test.basics > xrpld.rpc
@@ -162,9 +161,6 @@ test.protocol > test.unit_test
 test.protocol > xrpl.basics
 test.protocol > xrpl.json
 test.protocol > xrpl.protocol
-test.resource > test.unit_test
-test.resource > xrpl.basics
-test.resource > xrpl.resource
 test.rpc > test.jtx
 test.rpc > xrpl.basics
 test.rpc > xrpl.config
@@ -188,12 +184,6 @@ test.server > xrpld.core
 test.server > xrpl.json
 test.server > xrpl.protocol
 test.server > xrpl.server
-test.shamap > test.unit_test
-test.shamap > xrpl.basics
-test.shamap > xrpl.config
-test.shamap > xrpl.nodestore
-test.shamap > xrpl.protocol
-test.shamap > xrpl.shamap
 test.unit_test > xrpl.basics
 test.unit_test > xrpl.protocol
 tests.libxrpl > xrpl.basics
@@ -205,6 +195,7 @@ tests.libxrpl > xrpl.net
 tests.libxrpl > xrpl.nodestore
 tests.libxrpl > xrpl.protocol
 tests.libxrpl > xrpl.protocol_autogen
+tests.libxrpl > xrpl.resource
 tests.libxrpl > xrpl.server
 tests.libxrpl > xrpl.shamap
 tests.libxrpl > xrpl.tx
diff --git a/include/xrpl/basics/Number.h b/include/xrpl/basics/Number.h
index 8d8ad608ee..f8258110f2 100644
--- a/include/xrpl/basics/Number.h
+++ b/include/xrpl/basics/Number.h
@@ -643,19 +643,26 @@ public:
     std::pair<T, int>
     normalizeToRange() const;
 
+    class Access
+    {
+        /** May use ranges that don't fit the restrictions of the "real"
+         * normalizeToRange().
+         *
+         */
+        template <Integral64 T>
+        [[nodiscard]]
+        static std::pair<T, int>
+        normalizeToRangeImpl(
+            Number const& n,
+            T minMantissa,
+            T maxMantissa,
+            MantissaRange::CuspRoundingFix fix);
+
+        friend class Number;
+        friend class NumberTest;
+    };
+
 private:
-    /** May use ranges that don't fit the restrictions of the "real"
-     * normalizeToRange().
-     *
-     */
-    template <Integral64 T>
-    [[nodiscard]]
-    std::pair<T, int>
-    normalizeToRangeImpl(T minMantissa, T maxMantissa, MantissaRange::CuspRoundingFix fix) const;
-
-    // Number_test needs to use normalizeToRangeImpl
-    friend class Number_test;
-
     static thread_local RoundingMode mode;
     // The available ranges for mantissa
 
@@ -956,7 +963,8 @@ Number::normalizeToRange() const
 
     // Don't need to worry about the cuspRounding fix because rounding up will never take the
     // mantissa over maxMantissa with a ones digit value other than 0. 0 can safely be truncated.
-    return normalizeToRangeImpl(kMIN, kMAX, MantissaRange::CuspRoundingFix::Disabled);
+    return Access::normalizeToRangeImpl(
+        *this, kMIN, kMAX, MantissaRange::CuspRoundingFix::Disabled);
 }
 
 /** Only intended to be used in tests
@@ -968,11 +976,15 @@ Number::normalizeToRange() const
 template <Integral64 T>
 [[nodiscard]]
 std::pair<T, int>
-Number::normalizeToRangeImpl(T minMantissa, T maxMantissa, MantissaRange::CuspRoundingFix fix) const
+Number::Access::normalizeToRangeImpl(
+    Number const& n,
+    T minMantissa,
+    T maxMantissa,
+    MantissaRange::CuspRoundingFix fix)
 {
-    bool negative = mantissa_ < 0;
-    internalrep mantissa = externalToInternal(mantissa_);
-    int exponent = exponent_;
+    bool negative = n.mantissa_ < 0;
+    internalrep mantissa = externalToInternal(n.mantissa_);
+    int exponent = n.exponent_;
 
     if constexpr (std::is_unsigned_v<T>)
     {
diff --git a/include/xrpl/basics/Slice.h b/include/xrpl/basics/Slice.h
index 948d012958..f87ca063b8 100644
--- a/include/xrpl/basics/Slice.h
+++ b/include/xrpl/basics/Slice.h
@@ -211,15 +211,17 @@ operator<<(Stream& s, Slice const& v)
 }
 
 template <class T, std::size_t N>
-std::enable_if_t<std::is_same_v<T, char> || std::is_same_v<T, unsigned char>, Slice>
+Slice
 makeSlice(std::array<T, N> const& a)
+    requires(std::is_same_v<T, char> || std::is_same_v<T, unsigned char>)
 {
     return Slice(a.data(), a.size());
 }
 
 template <class T, class Alloc>
-std::enable_if_t<std::is_same_v<T, char> || std::is_same_v<T, unsigned char>, Slice>
+Slice
 makeSlice(std::vector<T, Alloc> const& v)
+    requires(std::is_same_v<T, char> || std::is_same_v<T, unsigned char>)
 {
     return Slice(v.data(), v.size());
 }
diff --git a/include/xrpl/basics/TaggedCache.h b/include/xrpl/basics/TaggedCache.h
index 71ebfc57a4..16c87cf833 100644
--- a/include/xrpl/basics/TaggedCache.h
+++ b/include/xrpl/basics/TaggedCache.h
@@ -212,11 +212,13 @@ public:
     */
     template <class ReturnType = bool>
     auto
-    insert(key_type const& key, T const& value) -> std::enable_if_t<!IsKeyCache, ReturnType>;
+    insert(key_type const& key, T const& value) -> ReturnType
+        requires(!IsKeyCache);
 
     template <class ReturnType = bool>
     auto
-    insert(key_type const& key) -> std::enable_if_t<IsKeyCache, ReturnType>;
+    insert(key_type const& key) -> ReturnType
+        requires IsKeyCache;
 
     // VFALCO NOTE It looks like this returns a copy of the data in
     //             the output parameter 'data'. This could be expensive.
diff --git a/include/xrpl/basics/TaggedCache.ipp b/include/xrpl/basics/TaggedCache.ipp
index ffcd533216..b79561c71a 100644
--- a/include/xrpl/basics/TaggedCache.ipp
+++ b/include/xrpl/basics/TaggedCache.ipp
@@ -57,7 +57,10 @@ inline TaggedCache<
         beast::insight::Collector::ptr const& collector)
     : journal_(journal)
     , clock_(clock)
-    , stats_(name, std::bind(&TaggedCache::collectMetrics, this), collector)
+    , stats_(
+          name,
+          [this] { collectMetrics(); },
+          collector)
     , name_(name)
     , targetSize_(size)
     , targetAge_(expiration)
@@ -500,7 +503,8 @@ template <
 template <class ReturnType>
 inline auto
 TaggedCache<Key, T, IsKeyCache, SharedWeakUnionPointer, SharedPointerType, Hash, KeyEqual, Mutex>::
-    insert(key_type const& key, T const& value) -> std::enable_if_t<!IsKeyCache, ReturnType>
+    insert(key_type const& key, T const& value) -> ReturnType
+    requires(!IsKeyCache)
 {
     static_assert(
         std::is_same_v<std::shared_ptr<T>, SharedPointerType> ||
@@ -530,7 +534,8 @@ template <
 template <class ReturnType>
 inline auto
 TaggedCache<Key, T, IsKeyCache, SharedWeakUnionPointer, SharedPointerType, Hash, KeyEqual, Mutex>::
-    insert(key_type const& key) -> std::enable_if_t<IsKeyCache, ReturnType>
+    insert(key_type const& key) -> ReturnType
+    requires IsKeyCache
 {
     std::scoped_lock const lock(mutex_);
     clock_type::time_point const now(clock_.now());
diff --git a/include/xrpl/basics/ToString.h b/include/xrpl/basics/ToString.h
index 7764c1e3e3..e9f8f43633 100644
--- a/include/xrpl/basics/ToString.h
+++ b/include/xrpl/basics/ToString.h
@@ -12,8 +12,9 @@ namespace xrpl {
  */
 
 template <class T>
-std::enable_if_t<std::is_arithmetic_v<T>, std::string>
+std::string
 to_string(T t)  // NOLINT(readability-identifier-naming)
+    requires(std::is_arithmetic_v<T>)
 {
     return std::to_string(t);
 }
diff --git a/include/xrpl/basics/base_uint.h b/include/xrpl/basics/base_uint.h
index c60fbf35b4..481a7dbd77 100644
--- a/include/xrpl/basics/base_uint.h
+++ b/include/xrpl/basics/base_uint.h
@@ -280,12 +280,11 @@ public:
     {
     }
 
-    template <
-        class Container,
-        class = std::enable_if_t<
-            detail::IsContiguousContainer<Container>::value &&
-            std::is_trivially_copyable_v<typename Container::value_type>>>
+    template <class Container>
     explicit BaseUInt(Container const& c)
+        requires(
+            detail::IsContiguousContainer<Container>::value &&
+            std::is_trivially_copyable_v<typename Container::value_type>)
     {
         // Use AlwaysFalseT so the static_assert condition is dependent
         // and only triggers when this constructor template is instantiated.
@@ -295,13 +294,12 @@ public:
             "Use base_uint::fromRaw instead.");
     }
 
-    template <
-        class Container,
-        class = std::enable_if_t<
-            detail::IsContiguousContainer<Container>::value &&
-            std::is_trivially_copyable_v<typename Container::value_type>>>
+    template <class Container>
     static BaseUInt
     fromRaw(Container const& c)
+        requires(
+            detail::IsContiguousContainer<Container>::value &&
+            std::is_trivially_copyable_v<typename Container::value_type>)
     {
         BaseUInt result;
         XRPL_ASSERT(
@@ -312,11 +310,11 @@ public:
     }
 
     template <class Container>
-    std::enable_if_t<
-        detail::IsContiguousContainer<Container>::value &&
-            std::is_trivially_copyable_v<typename Container::value_type>,
-        BaseUInt&>
+    BaseUInt&
     operator=(Container const& c)
+        requires(
+            detail::IsContiguousContainer<Container>::value &&
+            std::is_trivially_copyable_v<typename Container::value_type>)
     {
         XRPL_ASSERT(
             c.size() * sizeof(typename Container::value_type) == size(),
diff --git a/include/xrpl/basics/comparators.h b/include/xrpl/basics/comparators.h
deleted file mode 100644
index 0e21d38d6b..0000000000
--- a/include/xrpl/basics/comparators.h
+++ /dev/null
@@ -1,54 +0,0 @@
-#pragma once
-
-#include <functional>
-
-namespace xrpl {
-
-#ifdef _MSC_VER
-
-/*
- * MSVC 2019 version 16.9.0 added [[nodiscard]] to the std comparison
- * operator() functions. boost::bimap checks that the comparator is a
- * BinaryFunction, in part by calling the function and ignoring the value.
- * These two things don't play well together. These wrapper classes simply
- * strip [[nodiscard]] from operator() for use in boost::bimap.
- *
- * See also:
- *  https://www.boost.org/doc/libs/1_75_0/libs/bimap/doc/html/boost_bimap/the_tutorial/controlling_collection_types.html
- */
-
-template <class T = void>
-struct less
-{
-    using result_type = bool;
-
-    constexpr bool
-    operator()(T const& left, T const& right) const
-    {
-        return std::less<T>()(left, right);
-    }
-};
-
-template <class T = void>
-struct equal_to
-{
-    using result_type = bool;
-
-    constexpr bool
-    operator()(T const& left, T const& right) const
-    {
-        return std::equal_to<T>()(left, right);
-    }
-};
-
-#else
-
-template <class T = void>
-using less = std::less<T>;
-
-template <class T = void>
-using equal_to = std::equal_to<T>;
-
-#endif
-
-}  // namespace xrpl
diff --git a/include/xrpl/basics/random.h b/include/xrpl/basics/random.h
index cceaa6f029..c544e7d0c8 100644
--- a/include/xrpl/basics/random.h
+++ b/include/xrpl/basics/random.h
@@ -91,8 +91,9 @@ defaultPrng()
 */
 /** @{ */
 template <class Engine, class Integral>
-std::enable_if_t<std::is_integral_v<Integral> && detail::is_engine<Engine>::value, Integral>
+Integral
 randInt(Engine& engine, Integral min, Integral max)
+    requires(std::is_integral_v<Integral> && detail::is_engine<Engine>::value)
 {
     XRPL_ASSERT(max > min, "xrpl::randInt : max over min inputs");
 
@@ -103,36 +104,41 @@ randInt(Engine& engine, Integral min, Integral max)
 }
 
 template <class Integral>
-std::enable_if_t<std::is_integral_v<Integral>, Integral>
+Integral
 randInt(Integral min, Integral max)
+    requires(std::is_integral_v<Integral>)
 {
     return randInt(defaultPrng(), min, max);
 }
 
 template <class Engine, class Integral>
-std::enable_if_t<std::is_integral_v<Integral> && detail::is_engine<Engine>::value, Integral>
+Integral
 randInt(Engine& engine, Integral max)
+    requires(std::is_integral_v<Integral> && detail::is_engine<Engine>::value)
 {
     return randInt(engine, Integral(0), max);
 }
 
 template <class Integral>
-std::enable_if_t<std::is_integral_v<Integral>, Integral>
+Integral
 randInt(Integral max)
+    requires(std::is_integral_v<Integral>)
 {
     return randInt(defaultPrng(), max);
 }
 
 template <class Integral, class Engine>
-std::enable_if_t<std::is_integral_v<Integral> && detail::is_engine<Engine>::value, Integral>
+Integral
 randInt(Engine& engine)
+    requires(std::is_integral_v<Integral> && detail::is_engine<Engine>::value)
 {
     return randInt(engine, std::numeric_limits<Integral>::max());
 }
 
 template <class Integral = int>
-std::enable_if_t<std::is_integral_v<Integral>, Integral>
+Integral
 randInt()
+    requires(std::is_integral_v<Integral>)
 {
     return randInt(defaultPrng(), std::numeric_limits<Integral>::max());
 }
@@ -141,19 +147,20 @@ randInt()
 /** Return a random byte */
 /** @{ */
 template <class Byte, class Engine>
-std::enable_if_t<
-    (std::is_same_v<Byte, unsigned char> || std::is_same_v<Byte, std::uint8_t>) &&
-        detail::is_engine<Engine>::value,
-    Byte>
+Byte
 randByte(Engine& engine)
+    requires(
+        (std::is_same_v<Byte, unsigned char> || std::is_same_v<Byte, std::uint8_t>) &&
+        detail::is_engine<Engine>::value)
 {
     return static_cast<Byte>(randInt<Engine, std::uint32_t>(
         engine, std::numeric_limits<Byte>::min(), std::numeric_limits<Byte>::max()));
 }
 
 template <class Byte = std::uint8_t>
-std::enable_if_t<(std::is_same_v<Byte, unsigned char> || std::is_same_v<Byte, std::uint8_t>), Byte>
+Byte
 randByte()
+    requires(std::is_same_v<Byte, unsigned char> || std::is_same_v<Byte, std::uint8_t>)
 {
     return randByte<Byte>(defaultPrng());
 }
diff --git a/include/xrpl/basics/safe_cast.h b/include/xrpl/basics/safe_cast.h
index 714146e089..7f2b93a7eb 100644
--- a/include/xrpl/basics/safe_cast.h
+++ b/include/xrpl/basics/safe_cast.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <xrpl/beast/utility/instrumentation.h>  // IWYU pragma: keep
+
 #include <type_traits>
 
 namespace xrpl {
@@ -15,8 +17,9 @@ concept SafeToCast = (std::is_integral_v<Src> && std::is_integral_v<Dest>) &&
                                                      : sizeof(Dest) >= sizeof(Src));
 
 template <class Dest, class Src>
-constexpr std::enable_if_t<std::is_integral_v<Dest> && std::is_integral_v<Src>, Dest>
+constexpr Dest
 safeCast(Src s) noexcept
+    requires(std::is_integral_v<Dest> && std::is_integral_v<Src>)
 {
     static_assert(
         std::is_signed_v<Dest> || std::is_unsigned_v<Src>, "Cannot cast signed to unsigned");
@@ -28,15 +31,17 @@ safeCast(Src s) noexcept
 }
 
 template <class Dest, class Src>
-constexpr std::enable_if_t<std::is_enum_v<Dest> && std::is_integral_v<Src>, Dest>
+constexpr Dest
 safeCast(Src s) noexcept
+    requires(std::is_enum_v<Dest> && std::is_integral_v<Src>)
 {
     return static_cast<Dest>(safeCast<std::underlying_type_t<Dest>>(s));
 }
 
 template <class Dest, class Src>
-constexpr std::enable_if_t<std::is_integral_v<Dest> && std::is_enum_v<Src>, Dest>
+constexpr Dest
 safeCast(Src s) noexcept
+    requires(std::is_integral_v<Dest> && std::is_enum_v<Src>)
 {
     return safeCast<Dest>(static_cast<std::underlying_type_t<Src>>(s));
 }
@@ -46,8 +51,9 @@ safeCast(Src s) noexcept
 // underlying types become safe, it can be converted to a safe_cast.
 
 template <class Dest, class Src>
-constexpr std::enable_if_t<std::is_integral_v<Dest> && std::is_integral_v<Src>, Dest>
+constexpr Dest
 unsafeCast(Src s) noexcept
+    requires(std::is_integral_v<Dest> && std::is_integral_v<Src>)
 {
     static_assert(
         !SafeToCast<Src, Dest>,
@@ -57,15 +63,17 @@ unsafeCast(Src s) noexcept
 }
 
 template <class Dest, class Src>
-constexpr std::enable_if_t<std::is_enum_v<Dest> && std::is_integral_v<Src>, Dest>
+constexpr Dest
 unsafeCast(Src s) noexcept
+    requires(std::is_enum_v<Dest> && std::is_integral_v<Src>)
 {
     return static_cast<Dest>(unsafeCast<std::underlying_type_t<Dest>>(s));
 }
 
 template <class Dest, class Src>
-constexpr std::enable_if_t<std::is_integral_v<Dest> && std::is_enum_v<Src>, Dest>
+constexpr Dest
 unsafeCast(Src s) noexcept
+    requires(std::is_integral_v<Dest> && std::is_enum_v<Src>)
 {
     return unsafeCast<Dest>(static_cast<std::underlying_type_t<Src>>(s));
 }
diff --git a/include/xrpl/basics/scope.h b/include/xrpl/basics/scope.h
index cfd21e6e30..e63bb69eb5 100644
--- a/include/xrpl/basics/scope.h
+++ b/include/xrpl/basics/scope.h
@@ -46,11 +46,9 @@ public:
     operator=(ScopeExit&&) = delete;
 
     template <class EFP>
-    explicit ScopeExit(
-        EFP&& f,
-        std::enable_if_t<
-            !std::is_same_v<std::remove_cv_t<EFP>, ScopeExit> &&
-            std::is_constructible_v<EF, EFP>>* = 0) noexcept
+    explicit ScopeExit(EFP&& f) noexcept
+        requires(
+            !std::is_same_v<std::remove_cv_t<EFP>, ScopeExit> && std::is_constructible_v<EF, EFP>)
         : exitFunction_{std::forward<EFP>(f)}
     {
         static_assert(std::is_nothrow_constructible_v<EF, decltype(std::forward<EFP>(f))>);
@@ -93,11 +91,9 @@ public:
     operator=(ScopeFail&&) = delete;
 
     template <class EFP>
-    explicit ScopeFail(
-        EFP&& f,
-        std::enable_if_t<
-            !std::is_same_v<std::remove_cv_t<EFP>, ScopeFail> &&
-            std::is_constructible_v<EF, EFP>>* = 0) noexcept
+    explicit ScopeFail(EFP&& f) noexcept
+        requires(
+            !std::is_same_v<std::remove_cv_t<EFP>, ScopeFail> && std::is_constructible_v<EF, EFP>)
         : exitFunction_{std::forward<EFP>(f)}
     {
         static_assert(std::is_nothrow_constructible_v<EF, decltype(std::forward<EFP>(f))>);
@@ -140,12 +136,11 @@ public:
     operator=(ScopeSuccess&&) = delete;
 
     template <class EFP>
-    explicit ScopeSuccess(
-        EFP&& f,
-        std::enable_if_t<
+    explicit ScopeSuccess(EFP&& f) noexcept(
+        std::is_nothrow_constructible_v<EF, EFP> || std::is_nothrow_constructible_v<EF, EFP&>)
+        requires(
             !std::is_same_v<std::remove_cv_t<EFP>, ScopeSuccess> &&
-            std::is_constructible_v<EF, EFP>>* =
-            0) noexcept(std::is_nothrow_constructible_v<EF, EFP> || std::is_nothrow_constructible_v<EF, EFP&>)
+            std::is_constructible_v<EF, EFP>)
         : exitFunction_{std::forward<EFP>(f)}
     {
     }
diff --git a/include/xrpl/basics/tagged_integer.h b/include/xrpl/basics/tagged_integer.h
index 8fbd2a274b..5a088db863 100644
--- a/include/xrpl/basics/tagged_integer.h
+++ b/include/xrpl/basics/tagged_integer.h
@@ -43,10 +43,10 @@ public:
 
     TaggedInteger() = default;
 
-    template <
-        class OtherInt,
-        class = std::enable_if_t<std::is_integral_v<OtherInt> && sizeof(OtherInt) <= sizeof(Int)>>
-    explicit constexpr TaggedInteger(OtherInt value) noexcept : value_(value)
+    template <class OtherInt>
+    explicit constexpr TaggedInteger(OtherInt value) noexcept
+        requires(std::is_integral_v<OtherInt> && sizeof(OtherInt) <= sizeof(Int))
+        : value_(value)
     {
         static_assert(sizeof(TaggedInteger) == sizeof(Int), "tagged_integer is adding padding");
     }
diff --git a/include/xrpl/beast/container/aged_container_utility.h b/include/xrpl/beast/container/aged_container_utility.h
index 7cda863fab..f43e59b0f7 100644
--- a/include/xrpl/beast/container/aged_container_utility.h
+++ b/include/xrpl/beast/container/aged_container_utility.h
@@ -4,14 +4,14 @@
 
 #include <chrono>
 #include <cstddef>
-#include <type_traits>
 
 namespace beast {
 
 /** Expire aged container items past the specified age. */
 template <class AgedContainer, class Rep, class Period>
-std::enable_if_t<IsAgedContainer<AgedContainer>::value, std::size_t>
+std::size_t
 expire(AgedContainer& c, std::chrono::duration<Rep, Period> const& age)
+    requires(IsAgedContainer<AgedContainer>::value)
 {
     std::size_t n(0);
     auto const expired(c.clock().now() - age);
diff --git a/include/xrpl/beast/container/detail/aged_container_iterator.h b/include/xrpl/beast/container/detail/aged_container_iterator.h
index 02fb3927dd..d6c061bb86 100644
--- a/include/xrpl/beast/container/detail/aged_container_iterator.h
+++ b/include/xrpl/beast/container/detail/aged_container_iterator.h
@@ -30,20 +30,19 @@ public:
 
     // Disable constructing a const_iterator from a non-const_iterator.
     // Converting between reverse and non-reverse iterators should be explicit.
-    template <
-        bool OtherIsConst,
-        class OtherIterator,
-        class = std::enable_if_t<
-            (!OtherIsConst || IsConst) &&
-            !static_cast<bool>(std::is_same_v<Iterator, OtherIterator>)>>
+    template <bool OtherIsConst, class OtherIterator>
     explicit AgedContainerIterator(AgedContainerIterator<OtherIsConst, OtherIterator> const& other)
+        requires(
+            (!OtherIsConst || IsConst) &&
+            !static_cast<bool>(std::is_same_v<Iterator, OtherIterator>))
         : iter_(other.iter_)
     {
     }
 
     // Disable constructing a const_iterator from a non-const_iterator.
-    template <bool OtherIsConst, class = std::enable_if_t<!OtherIsConst || IsConst>>
+    template <bool OtherIsConst>
     AgedContainerIterator(AgedContainerIterator<OtherIsConst, Iterator> const& other)
+        requires(!OtherIsConst || IsConst)
         : iter_(other.iter_)
     {
     }
@@ -52,7 +51,8 @@ public:
     template <bool OtherIsConst, class OtherIterator>
     auto
     operator=(AgedContainerIterator<OtherIsConst, OtherIterator> const& other)
-        -> std::enable_if_t<!OtherIsConst || IsConst, AgedContainerIterator&>
+        -> AgedContainerIterator&
+        requires(!OtherIsConst || IsConst)
     {
         iter_ = other.iter_;
         return *this;
diff --git a/include/xrpl/beast/container/detail/aged_ordered_container.h b/include/xrpl/beast/container/detail/aged_ordered_container.h
index 0533a51f00..f739f05d2c 100644
--- a/include/xrpl/beast/container/detail/aged_ordered_container.h
+++ b/include/xrpl/beast/container/detail/aged_ordered_container.h
@@ -111,10 +111,9 @@ private:
         {
         }
 
-        template <
-            class... Args,
-            class = std::enable_if_t<std::is_constructible_v<value_type, Args...>>>
+        template <class... Args>
         Element(time_point const& when, Args&&... args)
+            requires(std::is_constructible_v<value_type, Args...>)
             : value(std::forward<Args>(args)...), when(when)
         {
         }
@@ -608,35 +607,25 @@ public:
     //
     //--------------------------------------------------------------------------
 
-    template <
-        class K,
-        bool MaybeMulti = IsMulti,
-        bool MaybeMap = IsMap,
-        class = std::enable_if_t<MaybeMap && !MaybeMulti>>
+    template <class K, bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
     std::conditional_t<IsMap, T, void*>&
-    at(K const& k);
+    at(K const& k)
+        requires(MaybeMap && !MaybeMulti);
 
-    template <
-        class K,
-        bool MaybeMulti = IsMulti,
-        bool MaybeMap = IsMap,
-        class = std::enable_if_t<MaybeMap && !MaybeMulti>>
+    template <class K, bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
     std::conditional<IsMap, T, void*>::type const&
-    at(K const& k) const;
+    at(K const& k) const
+        requires(MaybeMap && !MaybeMulti);
 
-    template <
-        bool MaybeMulti = IsMulti,
-        bool MaybeMap = IsMap,
-        class = std::enable_if_t<MaybeMap && !MaybeMulti>>
+    template <bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
     std::conditional_t<IsMap, T, void*>&
-    operator[](Key const& key);
+    operator[](Key const& key)
+        requires(MaybeMap && !MaybeMulti);
 
-    template <
-        bool MaybeMulti = IsMulti,
-        bool MaybeMap = IsMap,
-        class = std::enable_if_t<MaybeMap && !MaybeMulti>>
+    template <bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
     std::conditional_t<IsMap, T, void*>&
-    operator[](Key&& key);
+    operator[](Key&& key)
+        requires(MaybeMap && !MaybeMulti);
 
     //--------------------------------------------------------------------------
     //
@@ -770,35 +759,40 @@ public:
     // map, set
     template <bool MaybeMulti = IsMulti>
     auto
-    insert(value_type const& value) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>;
+    insert(value_type const& value) -> std::pair<iterator, bool>
+        requires(!MaybeMulti);
 
     // multimap, multiset
     template <bool MaybeMulti = IsMulti>
     auto
-    insert(value_type const& value) -> std::enable_if_t<MaybeMulti, iterator>;
+    insert(value_type const& value) -> iterator
+        requires MaybeMulti;
 
     // set
     template <bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
     auto
-    insert(value_type&& value)
-        -> std::enable_if_t<!MaybeMulti && !MaybeMap, std::pair<iterator, bool>>;
+    insert(value_type&& value) -> std::pair<iterator, bool>
+        requires(!MaybeMulti && !MaybeMap);
 
     // multiset
     template <bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
     auto
-    insert(value_type&& value) -> std::enable_if_t<MaybeMulti && !MaybeMap, iterator>;
+    insert(value_type&& value) -> iterator
+        requires(MaybeMulti && !MaybeMap);
 
     //---
 
     // map, set
     template <bool MaybeMulti = IsMulti>
     auto
-    insert(const_iterator hint, value_type const& value) -> std::enable_if_t<!MaybeMulti, iterator>;
+    insert(const_iterator hint, value_type const& value) -> iterator
+        requires(!MaybeMulti);
 
     // multimap, multiset
     template <bool MaybeMulti = IsMulti>
-    std::enable_if_t<MaybeMulti, iterator>
+    iterator
     insert(const_iterator /*hint*/, value_type const& value)
+        requires MaybeMulti
     {
         // VFALCO TODO Figure out how to utilize 'hint'
         return insert(value);
@@ -807,12 +801,14 @@ public:
     // map, set
     template <bool MaybeMulti = IsMulti>
     auto
-    insert(const_iterator hint, value_type&& value) -> std::enable_if_t<!MaybeMulti, iterator>;
+    insert(const_iterator hint, value_type&& value) -> iterator
+        requires(!MaybeMulti);
 
     // multimap, multiset
     template <bool MaybeMulti = IsMulti>
-    std::enable_if_t<MaybeMulti, iterator>
+    iterator
     insert(const_iterator /*hint*/, value_type&& value)
+        requires MaybeMulti
     {
         // VFALCO TODO Figure out how to utilize 'hint'
         return insert(std::move(value));
@@ -820,20 +816,18 @@ public:
 
     // map, multimap
     template <class P, bool MaybeMap = IsMap>
-    std::enable_if_t<
-        MaybeMap && std::is_constructible_v<value_type, P&&>,
-        std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>>
+    std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>
     insert(P&& value)
+        requires(MaybeMap && std::is_constructible_v<value_type, P &&>)
     {
         return emplace(std::forward<P>(value));
     }
 
     // map, multimap
     template <class P, bool MaybeMap = IsMap>
-    std::enable_if_t<
-        MaybeMap && std::is_constructible_v<value_type, P&&>,
-        std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>>
+    std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>
     insert(const_iterator hint, P&& value)
+        requires(MaybeMap && std::is_constructible_v<value_type, P &&>)
     {
         return emplaceHint(hint, std::forward<P>(value));
     }
@@ -855,46 +849,45 @@ public:
     // map, set
     template <bool MaybeMulti = IsMulti, class... Args>
     auto
-    emplace(Args&&... args) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>;
+    emplace(Args&&... args) -> std::pair<iterator, bool>
+        requires(!MaybeMulti);
 
     // multiset, multimap
     template <bool MaybeMulti = IsMulti, class... Args>
     auto
-    emplace(Args&&... args) -> std::enable_if_t<MaybeMulti, iterator>;
+    emplace(Args&&... args) -> iterator
+        requires MaybeMulti;
 
     // map, set
     template <bool MaybeMulti = IsMulti, class... Args>
     auto
-    emplaceHint(const_iterator hint, Args&&... args)
-        -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>;
+    emplaceHint(const_iterator hint, Args&&... args) -> std::pair<iterator, bool>
+        requires(!MaybeMulti);
 
     // multiset, multimap
     template <bool MaybeMulti = IsMulti, class... Args>
-    std::enable_if_t<MaybeMulti, iterator>
+    iterator
     emplaceHint(const_iterator /*hint*/, Args&&... args)
+        requires MaybeMulti
     {
         // VFALCO TODO Figure out how to utilize 'hint'
         return emplace<MaybeMulti>(std::forward<Args>(args)...);
     }
 
-    // enable_if prevents erase (reverse_iterator pos) from compiling
-    template <
-        bool IsConst,
-        class Iterator,
-        class = std::enable_if_t<!IsBoostReverseIterator<Iterator>::value>>
+    // The constraint prevents erase (reverse_iterator pos) from compiling
+    template <bool IsConst, class Iterator>
     beast::detail::AgedContainerIterator<false, Iterator>
-    erase(beast::detail::AgedContainerIterator<IsConst, Iterator> pos);
+    erase(beast::detail::AgedContainerIterator<IsConst, Iterator> pos)
+        requires(!IsBoostReverseIterator<Iterator>::value);
 
-    // enable_if prevents erase (reverse_iterator first, reverse_iterator last)
+    // The constraint prevents erase (reverse_iterator first, reverse_iterator last)
     // from compiling
-    template <
-        bool IsConst,
-        class Iterator,
-        class = std::enable_if_t<!IsBoostReverseIterator<Iterator>::value>>
+    template <bool IsConst, class Iterator>
     beast::detail::AgedContainerIterator<false, Iterator>
     erase(
         beast::detail::AgedContainerIterator<IsConst, Iterator> first,
-        beast::detail::AgedContainerIterator<IsConst, Iterator> last);
+        beast::detail::AgedContainerIterator<IsConst, Iterator> last)
+        requires(!IsBoostReverseIterator<Iterator>::value);
 
     template <class K>
     auto
@@ -905,13 +898,11 @@ public:
 
     //--------------------------------------------------------------------------
 
-    // enable_if prevents touch (reverse_iterator pos) from compiling
-    template <
-        bool IsConst,
-        class Iterator,
-        class = std::enable_if_t<!IsBoostReverseIterator<Iterator>::value>>
+    // The constraint prevents touch (reverse_iterator pos) from compiling
+    template <bool IsConst, class Iterator>
     void
     touch(beast::detail::AgedContainerIterator<IsConst, Iterator> pos)
+        requires(!IsBoostReverseIterator<Iterator>::value)
     {
         touch(pos, clock().now());
     }
@@ -1142,25 +1133,25 @@ public:
     }
 
 private:
-    // enable_if prevents erase (reverse_iterator pos, now) from compiling
-    template <
-        bool IsConst,
-        class Iterator,
-        class = std::enable_if_t<!IsBoostReverseIterator<Iterator>::value>>
+    // The constraint prevents erase (reverse_iterator pos, now) from compiling
+    template <bool IsConst, class Iterator>
     void
     touch(
         beast::detail::AgedContainerIterator<IsConst, Iterator> pos,
-        clock_type::time_point const& now);
+        clock_type::time_point const& now)
+        requires(!IsBoostReverseIterator<Iterator>::value);
 
     template <
         bool MaybePropagate = std::allocator_traits<Allocator>::propagate_on_container_swap::value>
-    std::enable_if_t<MaybePropagate>
-    swapData(AgedOrderedContainer& other) noexcept;
+    void
+    swapData(AgedOrderedContainer& other) noexcept
+        requires MaybePropagate;
 
     template <
         bool MaybePropagate = std::allocator_traits<Allocator>::propagate_on_container_swap::value>
-    std::enable_if_t<!MaybePropagate>
-    swapData(AgedOrderedContainer& other) noexcept;
+    void
+    swapData(AgedOrderedContainer& other) noexcept
+        requires(!MaybePropagate);
 
 private:
     ConfigT config_;
@@ -1369,9 +1360,10 @@ AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::operato
 //------------------------------------------------------------------------------
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
-template <class K, bool MaybeMulti, bool MaybeMap, class>
+template <class K, bool MaybeMulti, bool MaybeMap>
 std::conditional_t<IsMap, T, void*>&
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::at(K const& k)
+    requires(MaybeMap && !MaybeMulti)
 {
     auto const iter(cont_.find(k, std::cref(config_.keyCompare())));
     if (iter == cont_.end())
@@ -1380,9 +1372,10 @@ AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::at(K co
 }
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
-template <class K, bool MaybeMulti, bool MaybeMap, class>
+template <class K, bool MaybeMulti, bool MaybeMap>
 std::conditional<IsMap, T, void*>::type const&
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::at(K const& k) const
+    requires(MaybeMap && !MaybeMulti)
 {
     auto const iter(cont_.find(k, std::cref(config_.keyCompare())));
     if (iter == cont_.end())
@@ -1391,9 +1384,10 @@ AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::at(K co
 }
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
-template <bool MaybeMulti, bool MaybeMap, class>
+template <bool MaybeMulti, bool MaybeMap>
 std::conditional_t<IsMap, T, void*>&
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::operator[](Key const& key)
+    requires(MaybeMap && !MaybeMulti)
 {
     typename cont_type::insert_commit_data d;
     auto const result(cont_.insert_check(key, std::cref(config_.keyCompare()), d));
@@ -1409,9 +1403,10 @@ AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::operato
 }
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
-template <bool MaybeMulti, bool MaybeMap, class>
+template <bool MaybeMulti, bool MaybeMap>
 std::conditional_t<IsMap, T, void*>&
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::operator[](Key&& key)
+    requires(MaybeMap && !MaybeMulti)
 {
     typename cont_type::insert_commit_data d;
     auto const result(cont_.insert_check(key, std::cref(config_.keyCompare()), d));
@@ -1445,7 +1440,8 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool MaybeMulti>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(
-    value_type const& value) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>
+    value_type const& value) -> std::pair<iterator, bool>
+    requires(!MaybeMulti)
 {
     typename cont_type::insert_commit_data d;
     auto const result(cont_.insert_check(extract(value), std::cref(config_.keyCompare()), d));
@@ -1464,7 +1460,8 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool MaybeMulti>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(
-    value_type const& value) -> std::enable_if_t<MaybeMulti, iterator>
+    value_type const& value) -> iterator
+    requires MaybeMulti
 {
     auto const before(cont_.upper_bound(extract(value), std::cref(config_.keyCompare())));
     Element* const p(newElement(value));
@@ -1478,7 +1475,8 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool MaybeMulti, bool MaybeMap>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(value_type&& value)
-    -> std::enable_if_t<!MaybeMulti && !MaybeMap, std::pair<iterator, bool>>
+    -> std::pair<iterator, bool>
+    requires(!MaybeMulti && !MaybeMap)
 {
     typename cont_type::insert_commit_data d;
     auto const result(cont_.insert_check(extract(value), std::cref(config_.keyCompare()), d));
@@ -1497,7 +1495,8 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool MaybeMulti, bool MaybeMap>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(value_type&& value)
-    -> std::enable_if_t<MaybeMulti && !MaybeMap, iterator>
+    -> iterator
+    requires(MaybeMulti && !MaybeMap)
 {
     auto const before(cont_.upper_bound(extract(value), std::cref(config_.keyCompare())));
     Element* const p(newElement(std::move(value)));
@@ -1514,7 +1513,8 @@ template <bool MaybeMulti>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(
     const_iterator hint,
-    value_type const& value) -> std::enable_if_t<!MaybeMulti, iterator>
+    value_type const& value) -> iterator
+    requires(!MaybeMulti)
 {
     typename cont_type::insert_commit_data d;
     auto const result(
@@ -1535,7 +1535,8 @@ template <bool MaybeMulti>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(
     const_iterator hint,
-    value_type&& value) -> std::enable_if_t<!MaybeMulti, iterator>
+    value_type&& value) -> iterator
+    requires(!MaybeMulti)
 {
     typename cont_type::insert_commit_data d;
     auto const result(
@@ -1555,7 +1556,8 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool MaybeMulti, class... Args>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::emplace(Args&&... args)
-    -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>
+    -> std::pair<iterator, bool>
+    requires(!MaybeMulti)
 {
     // VFALCO NOTE Its unfortunate that we need to
     //             construct element here
@@ -1577,7 +1579,8 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool MaybeMulti, class... Args>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::emplace(Args&&... args)
-    -> std::enable_if_t<MaybeMulti, iterator>
+    -> iterator
+    requires MaybeMulti
 {
     Element* const p(newElement(std::forward<Args>(args)...));
     auto const before(cont_.upper_bound(extract(p->value), std::cref(config_.keyCompare())));
@@ -1592,7 +1595,8 @@ template <bool MaybeMulti, class... Args>
 auto
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::emplaceHint(
     const_iterator hint,
-    Args&&... args) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>
+    Args&&... args) -> std::pair<iterator, bool>
+    requires(!MaybeMulti)
 {
     // VFALCO NOTE Its unfortunate that we need to
     //             construct element here
@@ -1611,21 +1615,23 @@ AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::emplace
 }
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
-template <bool IsConst, class Iterator, class>
+template <bool IsConst, class Iterator>
 beast::detail::AgedContainerIterator<false, Iterator>
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::erase(
     beast::detail::AgedContainerIterator<IsConst, Iterator> pos)
+    requires(!IsBoostReverseIterator<Iterator>::value)
 {
     unlinkAndDeleteElement(&*((pos++).iterator()));
     return beast::detail::AgedContainerIterator<false, Iterator>(pos.iterator());
 }
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
-template <bool IsConst, class Iterator, class>
+template <bool IsConst, class Iterator>
 beast::detail::AgedContainerIterator<false, Iterator>
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::erase(
     beast::detail::AgedContainerIterator<IsConst, Iterator> first,
     beast::detail::AgedContainerIterator<IsConst, Iterator> last)
+    requires(!IsBoostReverseIterator<Iterator>::value)
 {
     for (; first != last;)
         unlinkAndDeleteElement(&*((first++).iterator()));
@@ -1728,11 +1734,12 @@ AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::operato
 //------------------------------------------------------------------------------
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
-template <bool IsConst, class Iterator, class>
+template <bool IsConst, class Iterator>
 void
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::touch(
     beast::detail::AgedContainerIterator<IsConst, Iterator> pos,
     clock_type::time_point const& now)
+    requires(!IsBoostReverseIterator<Iterator>::value)
 {
     auto& e(*pos.iterator());
     e.when = now;
@@ -1742,9 +1749,10 @@ AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::touch(
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
 template <bool MaybePropagate>
-std::enable_if_t<MaybePropagate>
+void
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::swapData(
     AgedOrderedContainer& other) noexcept
+    requires MaybePropagate
 {
     std::swap(config_.keyCompare(), other.config_.keyCompare());
     std::swap(config_.alloc(), other.config_.alloc());
@@ -1753,9 +1761,10 @@ AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::swapDat
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
 template <bool MaybePropagate>
-std::enable_if_t<!MaybePropagate>
+void
 AgedOrderedContainer<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::swapData(
     AgedOrderedContainer& other) noexcept
+    requires(!MaybePropagate)
 {
     std::swap(config_.keyCompare(), other.config_.keyCompare());
     std::swap(config_.clock, other.config_.clock);
diff --git a/include/xrpl/beast/container/detail/aged_unordered_container.h b/include/xrpl/beast/container/detail/aged_unordered_container.h
index 782f36cd52..ea24141bfb 100644
--- a/include/xrpl/beast/container/detail/aged_unordered_container.h
+++ b/include/xrpl/beast/container/detail/aged_unordered_container.h
@@ -117,10 +117,9 @@ private:
         {
         }
 
-        template <
-            class... Args,
-            class = std::enable_if_t<std::is_constructible_v<value_type, Args...>>>
+        template <class... Args>
         Element(time_point const& when, Args&&... args)
+            requires(std::is_constructible_v<value_type, Args...>)
             : value(std::forward<Args>(args)...), when(when)
         {
         }
@@ -841,35 +840,25 @@ public:
     //
     //--------------------------------------------------------------------------
 
-    template <
-        class K,
-        bool MaybeMulti = IsMulti,
-        bool MaybeMap = IsMap,
-        class = std::enable_if_t<MaybeMap && !MaybeMulti>>
+    template <class K, bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
     std::conditional_t<IsMap, T, void*>&
-    at(K const& k);
+    at(K const& k)
+        requires(MaybeMap && !MaybeMulti);
 
-    template <
-        class K,
-        bool MaybeMulti = IsMulti,
-        bool MaybeMap = IsMap,
-        class = std::enable_if_t<MaybeMap && !MaybeMulti>>
+    template <class K, bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
     std::conditional<IsMap, T, void*>::type const&
-    at(K const& k) const;
+    at(K const& k) const
+        requires(MaybeMap && !MaybeMulti);
 
-    template <
-        bool MaybeMulti = IsMulti,
-        bool MaybeMap = IsMap,
-        class = std::enable_if_t<MaybeMap && !MaybeMulti>>
+    template <bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
     std::conditional_t<IsMap, T, void*>&
-    operator[](Key const& key);
+    operator[](Key const& key)
+        requires(MaybeMap && !MaybeMulti);
 
-    template <
-        bool MaybeMulti = IsMulti,
-        bool MaybeMap = IsMap,
-        class = std::enable_if_t<MaybeMap && !MaybeMulti>>
+    template <bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
     std::conditional_t<IsMap, T, void*>&
-    operator[](Key&& key);
+    operator[](Key&& key)
+        requires(MaybeMap && !MaybeMulti);
 
     //--------------------------------------------------------------------------
     //
@@ -967,28 +956,32 @@ public:
     // map, set
     template <bool MaybeMulti = IsMulti>
     auto
-    insert(value_type const& value) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>;
+    insert(value_type const& value) -> std::pair<iterator, bool>
+        requires(!MaybeMulti);
 
     // multimap, multiset
     template <bool MaybeMulti = IsMulti>
     auto
-    insert(value_type const& value) -> std::enable_if_t<MaybeMulti, iterator>;
+    insert(value_type const& value) -> iterator
+        requires MaybeMulti;
 
     // map, set
     template <bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
     auto
-    insert(value_type&& value)
-        -> std::enable_if_t<!MaybeMulti && !MaybeMap, std::pair<iterator, bool>>;
+    insert(value_type&& value) -> std::pair<iterator, bool>
+        requires(!MaybeMulti && !MaybeMap);
 
     // multimap, multiset
     template <bool MaybeMulti = IsMulti, bool MaybeMap = IsMap>
     auto
-    insert(value_type&& value) -> std::enable_if_t<MaybeMulti && !MaybeMap, iterator>;
+    insert(value_type&& value) -> iterator
+        requires(MaybeMulti && !MaybeMap);
 
     // map, set
     template <bool MaybeMulti = IsMulti>
-    std::enable_if_t<!MaybeMulti, iterator>
+    iterator
     insert(const_iterator /*hint*/, value_type const& value)
+        requires(!MaybeMulti)
     {
         // Hint is ignored but we provide the interface so
         // callers may use ordered and unordered interchangeably.
@@ -997,8 +990,9 @@ public:
 
     // multimap, multiset
     template <bool MaybeMulti = IsMulti>
-    std::enable_if_t<MaybeMulti, iterator>
+    iterator
     insert(const_iterator /*hint*/, value_type const& value)
+        requires MaybeMulti
     {
         // VFALCO TODO The hint could be used to let
         //             the client order equal ranges
@@ -1007,8 +1001,9 @@ public:
 
     // map, set
     template <bool MaybeMulti = IsMulti>
-    std::enable_if_t<!MaybeMulti, iterator>
+    iterator
     insert(const_iterator /*hint*/, value_type&& value)
+        requires(!MaybeMulti)
     {
         // Hint is ignored but we provide the interface so
         // callers may use ordered and unordered interchangeably.
@@ -1017,8 +1012,9 @@ public:
 
     // multimap, multiset
     template <bool MaybeMulti = IsMulti>
-    std::enable_if_t<MaybeMulti, iterator>
+    iterator
     insert(const_iterator /*hint*/, value_type&& value)
+        requires MaybeMulti
     {
         // VFALCO TODO The hint could be used to let
         //             the client order equal ranges
@@ -1027,20 +1023,18 @@ public:
 
     // map, multimap
     template <class P, bool MaybeMap = IsMap>
-    std::enable_if_t<
-        MaybeMap && std::is_constructible_v<value_type, P&&>,
-        std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>>
+    std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>
     insert(P&& value)
+        requires(MaybeMap && std::is_constructible_v<value_type, P &&>)
     {
         return emplace(std::forward<P>(value));
     }
 
     // map, multimap
     template <class P, bool MaybeMap = IsMap>
-    std::enable_if_t<
-        MaybeMap && std::is_constructible_v<value_type, P&&>,
-        std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>>
+    std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>
     insert(const_iterator hint, P&& value)
+        requires(MaybeMap && std::is_constructible_v<value_type, P &&>)
     {
         return emplaceHint(hint, std::forward<P>(value));
     }
@@ -1061,23 +1055,26 @@ public:
     // set, map
     template <bool MaybeMulti = IsMulti, class... Args>
     auto
-    emplace(Args&&... args) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>;
+    emplace(Args&&... args) -> std::pair<iterator, bool>
+        requires(!MaybeMulti);
 
     // multiset, multimap
     template <bool MaybeMulti = IsMulti, class... Args>
     auto
-    emplace(Args&&... args) -> std::enable_if_t<MaybeMulti, iterator>;
+    emplace(Args&&... args) -> iterator
+        requires MaybeMulti;
 
     // set, map
     template <bool MaybeMulti = IsMulti, class... Args>
     auto
-    emplaceHint(const_iterator /*hint*/, Args&&... args)
-        -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>;
+    emplaceHint(const_iterator /*hint*/, Args&&... args) -> std::pair<iterator, bool>
+        requires(!MaybeMulti);
 
     // multiset, multimap
     template <bool MaybeMulti = IsMulti, class... Args>
-    std::enable_if_t<MaybeMulti, iterator>
+    iterator
     emplaceHint(const_iterator /*hint*/, Args&&... args)
+        requires MaybeMulti
     {
         // VFALCO TODO The hint could be used for multi, to let
         //             the client order equal ranges
@@ -1308,7 +1305,7 @@ public:
         class OtherHash,
         class OtherAllocator,
         bool MaybeMulti = IsMulti>
-    std::enable_if_t<!MaybeMulti, bool>
+    bool
     operator==(AgedUnorderedContainer<
                false,
                OtherIsMap,
@@ -1317,7 +1314,8 @@ public:
                OtherDuration,
                OtherHash,
                KeyEqual,
-               OtherAllocator> const& other) const;
+               OtherAllocator> const& other) const
+        requires(!MaybeMulti);
 
     template <
         bool OtherIsMap,
@@ -1327,7 +1325,7 @@ public:
         class OtherHash,
         class OtherAllocator,
         bool MaybeMulti = IsMulti>
-    std::enable_if_t<MaybeMulti, bool>
+    bool
     operator==(AgedUnorderedContainer<
                true,
                OtherIsMap,
@@ -1336,7 +1334,8 @@ public:
                OtherDuration,
                OtherHash,
                KeyEqual,
-               OtherAllocator> const& other) const;
+               OtherAllocator> const& other) const
+        requires MaybeMulti;
 
     template <
         bool OtherIsMulti,
@@ -1381,13 +1380,14 @@ private:
     // map, set
     template <bool MaybeMulti = IsMulti>
     auto
-    insertUnchecked(value_type const& value)
-        -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>;
+    insertUnchecked(value_type const& value) -> std::pair<iterator, bool>
+        requires(!MaybeMulti);
 
     // multimap, multiset
     template <bool MaybeMulti = IsMulti>
     auto
-    insertUnchecked(value_type const& value) -> std::enable_if_t<MaybeMulti, iterator>;
+    insertUnchecked(value_type const& value) -> iterator
+        requires MaybeMulti;
 
     template <class InputIt>
     void
@@ -1428,8 +1428,9 @@ private:
 
     template <
         bool MaybePropagate = std::allocator_traits<Allocator>::propagate_on_container_swap::value>
-    std::enable_if_t<MaybePropagate>
+    void
     swapData(AgedUnorderedContainer& other) noexcept
+        requires MaybePropagate
     {
         std::swap(config_.hashFunction(), other.config_.hashFunction());
         std::swap(config_.keyEq(), other.config_.keyEq());
@@ -1439,8 +1440,9 @@ private:
 
     template <
         bool MaybePropagate = std::allocator_traits<Allocator>::propagate_on_container_swap::value>
-    std::enable_if_t<!MaybePropagate>
+    void
     swapData(AgedUnorderedContainer& other) noexcept
+        requires(!MaybePropagate)
     {
         std::swap(config_.hashFunction(), other.config_.hashFunction());
         std::swap(config_.keyEq(), other.config_.keyEq());
@@ -2094,9 +2096,10 @@ template <
     class Hash,
     class KeyEqual,
     class Allocator>
-template <class K, bool MaybeMulti, bool MaybeMap, class>
+template <class K, bool MaybeMulti, bool MaybeMap>
 std::conditional_t<IsMap, T, void*>&
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::at(K const& k)
+    requires(MaybeMap && !MaybeMulti)
 {
     auto const iter(
         cont_.find(k, std::cref(config_.hashFunction()), std::cref(config_.keyValueEqual())));
@@ -2114,10 +2117,11 @@ template <
     class Hash,
     class KeyEqual,
     class Allocator>
-template <class K, bool MaybeMulti, bool MaybeMap, class>
+template <class K, bool MaybeMulti, bool MaybeMap>
 std::conditional<IsMap, T, void*>::type const&
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::at(
     K const& k) const
+    requires(MaybeMap && !MaybeMulti)
 {
     auto const iter(
         cont_.find(k, std::cref(config_.hashFunction()), std::cref(config_.keyValueEqual())));
@@ -2135,10 +2139,11 @@ template <
     class Hash,
     class KeyEqual,
     class Allocator>
-template <bool MaybeMulti, bool MaybeMap, class>
+template <bool MaybeMulti, bool MaybeMap>
 std::conditional_t<IsMap, T, void*>&
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::operator[](
     Key const& key)
+    requires(MaybeMap && !MaybeMulti)
 {
     maybeRehash(1);
     typename cont_type::insert_commit_data d;
@@ -2164,10 +2169,11 @@ template <
     class Hash,
     class KeyEqual,
     class Allocator>
-template <bool MaybeMulti, bool MaybeMap, class>
+template <bool MaybeMulti, bool MaybeMap>
 std::conditional_t<IsMap, T, void*>&
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::operator[](
     Key&& key)
+    requires(MaybeMap && !MaybeMulti)
 {
     maybeRehash(1);
     typename cont_type::insert_commit_data d;
@@ -2220,7 +2226,8 @@ template <
 template <bool MaybeMulti>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::insert(
-    value_type const& value) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>
+    value_type const& value) -> std::pair<iterator, bool>
+    requires(!MaybeMulti)
 {
     maybeRehash(1);
     typename cont_type::insert_commit_data d;
@@ -2249,7 +2256,8 @@ template <
 template <bool MaybeMulti>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::insert(
-    value_type const& value) -> std::enable_if_t<MaybeMulti, iterator>
+    value_type const& value) -> iterator
+    requires MaybeMulti
 {
     maybeRehash(1);
     Element* const p(newElement(value));
@@ -2271,7 +2279,8 @@ template <
 template <bool MaybeMulti, bool MaybeMap>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::insert(
-    value_type&& value) -> std::enable_if_t<!MaybeMulti && !MaybeMap, std::pair<iterator, bool>>
+    value_type&& value) -> std::pair<iterator, bool>
+    requires(!MaybeMulti && !MaybeMap)
 {
     maybeRehash(1);
     typename cont_type::insert_commit_data d;
@@ -2300,7 +2309,8 @@ template <
 template <bool MaybeMulti, bool MaybeMap>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::insert(
-    value_type&& value) -> std::enable_if_t<MaybeMulti && !MaybeMap, iterator>
+    value_type&& value) -> iterator
+    requires(MaybeMulti && !MaybeMap)
 {
     maybeRehash(1);
     Element* const p(newElement(std::move(value)));
@@ -2309,7 +2319,6 @@ AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>
     return iterator(iter);
 }
 
-#if 1  // Use insert() instead of insert_check() insert_commit()
 // set, map
 template <
     bool IsMulti,
@@ -2323,7 +2332,8 @@ template <
 template <bool MaybeMulti, class... Args>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::emplace(
-    Args&&... args) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>
+    Args&&... args) -> std::pair<iterator, bool>
+    requires(!MaybeMulti)
 {
     maybeRehash(1);
     // VFALCO NOTE Its unfortunate that we need to
@@ -2338,42 +2348,6 @@ AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>
     deleteElement(p);
     return std::make_pair(iterator(result.first), false);
 }
-#else   // As original, use insert_check() / insert_commit () pair.
-// set, map
-template <
-    bool IsMulti,
-    bool IsMap,
-    class Key,
-    class T,
-    class Clock,
-    class Hash,
-    class KeyEqual,
-    class Allocator>
-template <bool maybe_multi, class... Args>
-auto
-AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::emplace(
-    Args&&... args) -> typename std::enable_if<!maybe_multi, std::pair<iterator, bool>>::type
-{
-    maybe_rehash(1);
-    // VFALCO NOTE Its unfortunate that we need to
-    //             construct element here
-    element* const p(new_element(std::forward<Args>(args)...));
-    typename cont_type::insert_commit_data d;
-    auto const result(m_cont.insert_check(
-        extract(p->value),
-        std::cref(m_config.hashFunction()),
-        std::cref(m_config.keyValueEqual()),
-        d));
-    if (result.second)
-    {
-        auto const iter(m_cont.insert_commit(*p, d));
-        chronological.list.push_back(*p);
-        return std::make_pair(iterator(iter), true);
-    }
-    delete_element(p);
-    return std::make_pair(iterator(result.first), false);
-}
-#endif  // 0
 
 // multiset, multimap
 template <
@@ -2388,7 +2362,8 @@ template <
 template <bool MaybeMulti, class... Args>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::emplace(
-    Args&&... args) -> std::enable_if_t<MaybeMulti, iterator>
+    Args&&... args) -> iterator
+    requires MaybeMulti
 {
     maybeRehash(1);
     Element* const p(newElement(std::forward<Args>(args)...));
@@ -2411,7 +2386,8 @@ template <bool MaybeMulti, class... Args>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::emplaceHint(
     const_iterator /*hint*/,
-    Args&&... args) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>
+    Args&&... args) -> std::pair<iterator, bool>
+    requires(!MaybeMulti)
 {
     maybeRehash(1);
     // VFALCO NOTE Its unfortunate that we need to
@@ -2562,7 +2538,7 @@ template <
     class OtherHash,
     class OtherAllocator,
     bool MaybeMulti>
-std::enable_if_t<!MaybeMulti, bool>
+bool
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::operator==(
     AgedUnorderedContainer<
         false,
@@ -2573,6 +2549,7 @@ AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>
         OtherHash,
         KeyEqual,
         OtherAllocator> const& other) const
+    requires(!MaybeMulti)
 {
     if (size() != other.size())
         return false;
@@ -2602,7 +2579,7 @@ template <
     class OtherHash,
     class OtherAllocator,
     bool MaybeMulti>
-std::enable_if_t<MaybeMulti, bool>
+bool
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::operator==(
     AgedUnorderedContainer<
         true,
@@ -2613,6 +2590,7 @@ AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>
         OtherHash,
         KeyEqual,
         OtherAllocator> const& other) const
+    requires MaybeMulti
 {
     if (size() != other.size())
         return false;
@@ -2649,7 +2627,8 @@ template <
 template <bool MaybeMulti>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::insertUnchecked(
-    value_type const& value) -> std::enable_if_t<!MaybeMulti, std::pair<iterator, bool>>
+    value_type const& value) -> std::pair<iterator, bool>
+    requires(!MaybeMulti)
 {
     typename cont_type::insert_commit_data d;
     auto const result(cont_.insert_check(
@@ -2677,7 +2656,8 @@ template <
 template <bool MaybeMulti>
 auto
 AgedUnorderedContainer<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::insertUnchecked(
-    value_type const& value) -> std::enable_if_t<MaybeMulti, iterator>
+    value_type const& value) -> iterator
+    requires MaybeMulti
 {
     Element* const p(newElement(value));
     chronological.list_.push_back(*p);
diff --git a/include/xrpl/beast/core/LexicalCast.h b/include/xrpl/beast/core/LexicalCast.h
index 8faf90f53d..1162d83078 100644
--- a/include/xrpl/beast/core/LexicalCast.h
+++ b/include/xrpl/beast/core/LexicalCast.h
@@ -29,16 +29,18 @@ struct LexicalCast<std::string, In>
     explicit LexicalCast() = default;
 
     template <class Arithmetic = In>
-    std::enable_if_t<std::is_arithmetic_v<Arithmetic>, bool>
+    bool
     operator()(std::string& out, Arithmetic in)
+        requires(std::is_arithmetic_v<Arithmetic>)
     {
         out = std::to_string(in);
         return true;
     }
 
     template <class Enumeration = In>
-    std::enable_if_t<std::is_enum_v<Enumeration>, bool>
+    bool
     operator()(std::string& out, Enumeration in)
+        requires(std::is_enum_v<Enumeration>)
     {
         out = std::to_string(static_cast<std::underlying_type_t<Enumeration>>(in));
         return true;
@@ -56,8 +58,9 @@ struct LexicalCast<Out, std::string_view>
         "beast::LexicalCast can only be used with integral types");
 
     template <class Integral = Out>
-    std::enable_if_t<std::is_integral_v<Integral> && !std::is_same_v<Integral, bool>, bool>
+    bool
     operator()(Integral& out, std::string_view in) const
+        requires(std::is_integral_v<Integral> && !std::is_same_v<Integral, bool>)
     {
         auto first = in.data();
         auto last = in.data() + in.size();
diff --git a/include/xrpl/beast/core/LockFreeStack.h b/include/xrpl/beast/core/LockFreeStack.h
index 19225a4343..dd135d2d98 100644
--- a/include/xrpl/beast/core/LockFreeStack.h
+++ b/include/xrpl/beast/core/LockFreeStack.h
@@ -41,7 +41,7 @@ public:
     operator=(NodePtr node)
     {
         node_ = node;
-        return static_cast<LockFreeStackIterator&>(*this);
+        return *this;
     }
 
     LockFreeStackIterator&
diff --git a/include/xrpl/beast/hash/hash_append.h b/include/xrpl/beast/hash/hash_append.h
index 5f77f41e5d..3592ffbfe8 100644
--- a/include/xrpl/beast/hash/hash_append.h
+++ b/include/xrpl/beast/hash/hash_append.h
@@ -200,26 +200,29 @@ struct IsContiguouslyHashable<T[N], HashAlgorithm>
 // scalars
 
 template <class Hasher, class T>
-inline std::enable_if_t<IsContiguouslyHashable<T, Hasher>::value>
+inline void
 hash_append(Hasher& h, T const& t) noexcept
+    requires(IsContiguouslyHashable<T, Hasher>::value)
 {
     // NOLINTNEXTLINE(bugprone-sizeof-expression)
     h(static_cast<void const*>(std::addressof(t)), sizeof(t));
 }
 
 template <class Hasher, class T>
-inline std::enable_if_t<
-    !IsContiguouslyHashable<T, Hasher>::value &&
-    (std::is_integral_v<T> || std::is_pointer_v<T> || std::is_enum_v<T>)>
+inline void
 hash_append(Hasher& h, T t) noexcept
+    requires(
+        !IsContiguouslyHashable<T, Hasher>::value &&
+        (std::is_integral_v<T> || std::is_pointer_v<T> || std::is_enum_v<T>))
 {
     detail::reverseBytes(t);
     h(std::addressof(t), sizeof(t));
 }
 
 template <class Hasher, class T>
-inline std::enable_if_t<std::is_floating_point_v<T>>
+inline void
 hash_append(Hasher& h, T t) noexcept
+    requires(std::is_floating_point_v<T>)
 {
     if (t == 0)
         t = 0;
@@ -239,36 +242,44 @@ hash_append(Hasher& h, std::nullptr_t) noexcept
 // Forward declarations for ADL purposes
 
 template <class Hasher, class T, std::size_t N>
-std::enable_if_t<!IsContiguouslyHashable<T, Hasher>::value>
-hash_append(Hasher& h, T (&a)[N]) noexcept;
+void
+hash_append(Hasher& h, T (&a)[N]) noexcept
+    requires(!IsContiguouslyHashable<T, Hasher>::value);
 
 template <class Hasher, class CharT, class Traits, class Alloc>
-std::enable_if_t<!IsContiguouslyHashable<CharT, Hasher>::value>
-hash_append(Hasher& h, std::basic_string<CharT, Traits, Alloc> const& s) noexcept;
+void
+hash_append(Hasher& h, std::basic_string<CharT, Traits, Alloc> const& s) noexcept
+    requires(!IsContiguouslyHashable<CharT, Hasher>::value);
 
 template <class Hasher, class CharT, class Traits, class Alloc>
-std::enable_if_t<IsContiguouslyHashable<CharT, Hasher>::value>
-hash_append(Hasher& h, std::basic_string<CharT, Traits, Alloc> const& s) noexcept;
+void
+hash_append(Hasher& h, std::basic_string<CharT, Traits, Alloc> const& s) noexcept
+    requires(IsContiguouslyHashable<CharT, Hasher>::value);
 
 template <class Hasher, class T, class U>
-std::enable_if_t<!IsContiguouslyHashable<std::pair<T, U>, Hasher>::value>
-hash_append(Hasher& h, std::pair<T, U> const& p) noexcept;
+void
+hash_append(Hasher& h, std::pair<T, U> const& p) noexcept
+    requires(!IsContiguouslyHashable<std::pair<T, U>, Hasher>::value);
 
 template <class Hasher, class T, class Alloc>
-std::enable_if_t<!IsContiguouslyHashable<T, Hasher>::value>
-hash_append(Hasher& h, std::vector<T, Alloc> const& v) noexcept;
+void
+hash_append(Hasher& h, std::vector<T, Alloc> const& v) noexcept
+    requires(!IsContiguouslyHashable<T, Hasher>::value);
 
 template <class Hasher, class T, class Alloc>
-std::enable_if_t<IsContiguouslyHashable<T, Hasher>::value>
-hash_append(Hasher& h, std::vector<T, Alloc> const& v) noexcept;
+void
+hash_append(Hasher& h, std::vector<T, Alloc> const& v) noexcept
+    requires(IsContiguouslyHashable<T, Hasher>::value);
 
 template <class Hasher, class T, std::size_t N>
-std::enable_if_t<!IsContiguouslyHashable<std::array<T, N>, Hasher>::value>
-hash_append(Hasher& h, std::array<T, N> const& a) noexcept;
+void
+hash_append(Hasher& h, std::array<T, N> const& a) noexcept
+    requires(!IsContiguouslyHashable<std::array<T, N>, Hasher>::value);
 
 template <class Hasher, class... T>
-std::enable_if_t<!IsContiguouslyHashable<std::tuple<T...>, Hasher>::value>
-hash_append(Hasher& h, std::tuple<T...> const& t) noexcept;
+void
+hash_append(Hasher& h, std::tuple<T...> const& t) noexcept
+    requires(!IsContiguouslyHashable<std::tuple<T...>, Hasher>::value);
 
 template <class Hasher, class Key, class T, class Hash, class Pred, class Alloc>
 void
@@ -279,11 +290,13 @@ void
 hash_append(Hasher& h, std::unordered_set<Key, Hash, Pred, Alloc> const& s);
 
 template <class Hasher, class Key, class Compare, class Alloc>
-std::enable_if_t<!IsContiguouslyHashable<Key, Hasher>::value>
-hash_append(Hasher& h, boost::container::flat_set<Key, Compare, Alloc> const& v) noexcept;
+void
+hash_append(Hasher& h, boost::container::flat_set<Key, Compare, Alloc> const& v) noexcept
+    requires(!IsContiguouslyHashable<Key, Hasher>::value);
 template <class Hasher, class Key, class Compare, class Alloc>
-std::enable_if_t<IsContiguouslyHashable<Key, Hasher>::value>
-hash_append(Hasher& h, boost::container::flat_set<Key, Compare, Alloc> const& v) noexcept;
+void
+hash_append(Hasher& h, boost::container::flat_set<Key, Compare, Alloc> const& v) noexcept
+    requires(IsContiguouslyHashable<Key, Hasher>::value);
 template <class Hasher, class T0, class T1, class... T>
 void
 hash_append(Hasher& h, T0 const& t0, T1 const& t1, T const&... t) noexcept;
@@ -291,8 +304,9 @@ hash_append(Hasher& h, T0 const& t0, T1 const& t1, T const&... t) noexcept;
 // c-array
 
 template <class Hasher, class T, std::size_t N>
-std::enable_if_t<!IsContiguouslyHashable<T, Hasher>::value>
+void
 hash_append(Hasher& h, T (&a)[N]) noexcept
+    requires(!IsContiguouslyHashable<T, Hasher>::value)
 {
     for (auto const& t : a)
         hash_append(h, t);
@@ -301,8 +315,9 @@ hash_append(Hasher& h, T (&a)[N]) noexcept
 // basic_string
 
 template <class Hasher, class CharT, class Traits, class Alloc>
-inline std::enable_if_t<!IsContiguouslyHashable<CharT, Hasher>::value>
+inline void
 hash_append(Hasher& h, std::basic_string<CharT, Traits, Alloc> const& s) noexcept
+    requires(!IsContiguouslyHashable<CharT, Hasher>::value)
 {
     for (auto c : s)
         hash_append(h, c);
@@ -310,8 +325,9 @@ hash_append(Hasher& h, std::basic_string<CharT, Traits, Alloc> const& s) noexcep
 }
 
 template <class Hasher, class CharT, class Traits, class Alloc>
-inline std::enable_if_t<IsContiguouslyHashable<CharT, Hasher>::value>
+inline void
 hash_append(Hasher& h, std::basic_string<CharT, Traits, Alloc> const& s) noexcept
+    requires(IsContiguouslyHashable<CharT, Hasher>::value)
 {
     h(s.data(), s.size() * sizeof(CharT));
     hash_append(h, s.size());
@@ -320,8 +336,9 @@ hash_append(Hasher& h, std::basic_string<CharT, Traits, Alloc> const& s) noexcep
 // pair
 
 template <class Hasher, class T, class U>
-inline std::enable_if_t<!IsContiguouslyHashable<std::pair<T, U>, Hasher>::value>
+inline void
 hash_append(Hasher& h, std::pair<T, U> const& p) noexcept
+    requires(!IsContiguouslyHashable<std::pair<T, U>, Hasher>::value)
 {
     hash_append(h, p.first, p.second);
 }
@@ -329,8 +346,9 @@ hash_append(Hasher& h, std::pair<T, U> const& p) noexcept
 // vector
 
 template <class Hasher, class T, class Alloc>
-inline std::enable_if_t<!IsContiguouslyHashable<T, Hasher>::value>
+inline void
 hash_append(Hasher& h, std::vector<T, Alloc> const& v) noexcept
+    requires(!IsContiguouslyHashable<T, Hasher>::value)
 {
     for (auto const& t : v)
         hash_append(h, t);
@@ -338,8 +356,9 @@ hash_append(Hasher& h, std::vector<T, Alloc> const& v) noexcept
 }
 
 template <class Hasher, class T, class Alloc>
-inline std::enable_if_t<IsContiguouslyHashable<T, Hasher>::value>
+inline void
 hash_append(Hasher& h, std::vector<T, Alloc> const& v) noexcept
+    requires(IsContiguouslyHashable<T, Hasher>::value)
 {
     h(v.data(), v.size() * sizeof(T));
     hash_append(h, v.size());
@@ -348,57 +367,37 @@ hash_append(Hasher& h, std::vector<T, Alloc> const& v) noexcept
 // array
 
 template <class Hasher, class T, std::size_t N>
-std::enable_if_t<!IsContiguouslyHashable<std::array<T, N>, Hasher>::value>
+void
 hash_append(Hasher& h, std::array<T, N> const& a) noexcept
+    requires(!IsContiguouslyHashable<std::array<T, N>, Hasher>::value)
 {
     for (auto const& t : a)
         hash_append(h, t);
 }
 
 template <class Hasher, class Key, class Compare, class Alloc>
-std::enable_if_t<!IsContiguouslyHashable<Key, Hasher>::value>
+void
 hash_append(Hasher& h, boost::container::flat_set<Key, Compare, Alloc> const& v) noexcept
+    requires(!IsContiguouslyHashable<Key, Hasher>::value)
 {
     for (auto const& t : v)
         hash_append(h, t);
 }
 template <class Hasher, class Key, class Compare, class Alloc>
-std::enable_if_t<IsContiguouslyHashable<Key, Hasher>::value>
+void
 hash_append(Hasher& h, boost::container::flat_set<Key, Compare, Alloc> const& v) noexcept
+    requires(IsContiguouslyHashable<Key, Hasher>::value)
 {
     h(&(v.begin()), v.size() * sizeof(Key));
 }
 // tuple
 
-namespace detail {
-
-inline void
-forEachItem(...) noexcept
-{
-}
-
-template <class Hasher, class T>
-inline int
-hashOne(Hasher& h, T const& t) noexcept
-{
-    hash_append(h, t);
-    return 0;
-}
-
-template <class Hasher, class... T, std::size_t... I>
-inline void
-tuple_hash(Hasher& h, std::tuple<T...> const& t, std::index_sequence<I...>) noexcept
-{
-    for_each_item(hash_one(h, std::get<I>(t))...);
-}
-
-}  // namespace detail
-
 template <class Hasher, class... T>
-inline std::enable_if_t<!IsContiguouslyHashable<std::tuple<T...>, Hasher>::value>
+inline void
 hash_append(Hasher& h, std::tuple<T...> const& t) noexcept
+    requires(!IsContiguouslyHashable<std::tuple<T...>, Hasher>::value)
 {
-    detail::tuple_hash(h, t, std::index_sequence_for<T...>{});
+    std::apply([&h](auto const&... item) { (hash_append(h, item), ...); }, t);
 }
 
 // shared_ptr
diff --git a/include/xrpl/beast/hash/xxhasher.h b/include/xrpl/beast/hash/xxhasher.h
index 978bbc6917..73dbb8e8ab 100644
--- a/include/xrpl/beast/hash/xxhasher.h
+++ b/include/xrpl/beast/hash/xxhasher.h
@@ -124,14 +124,18 @@ public:
         }
     }
 
-    template <class Seed, std::enable_if_t<std::is_unsigned_v<Seed>>* = nullptr>
-    explicit Xxhasher(Seed seed) : seed_(seed)
+    template <class Seed>
+    explicit Xxhasher(Seed seed)
+        requires(std::is_unsigned_v<Seed>)
+        : seed_(seed)
     {
         resetBuffers();
     }
 
-    template <class Seed, std::enable_if_t<std::is_unsigned_v<Seed>>* = nullptr>
-    Xxhasher(Seed seed, Seed) : seed_(seed)
+    template <class Seed>
+    Xxhasher(Seed seed, Seed)
+        requires(std::is_unsigned_v<Seed>)
+        : seed_(seed)
     {
         resetBuffers();
     }
diff --git a/include/xrpl/beast/insight/Gauge.h b/include/xrpl/beast/insight/Gauge.h
index b24c4366c3..9a23ea6665 100644
--- a/include/xrpl/beast/insight/Gauge.h
+++ b/include/xrpl/beast/insight/Gauge.h
@@ -49,6 +49,11 @@ public:
             impl_->set(value);
     }
 
+    // This is a write-through handle: assignment sets the value of the
+    // referenced metric.  It is const-qualified and returns Gauge const&
+    // (a non-const Gauge& would require a const_cast), so it does not follow
+    // the conventional assignment-operator signature.
+    // NOLINTNEXTLINE(misc-unconventional-assign-operator)
     Gauge const&
     operator=(value_type value) const
     {
diff --git a/include/xrpl/beast/unit_test/thread.h b/include/xrpl/beast/unit_test/thread.h
index 0de039cb89..91d8cf3cab 100644
--- a/include/xrpl/beast/unit_test/thread.h
+++ b/include/xrpl/beast/unit_test/thread.h
@@ -45,7 +45,10 @@ public:
     template <class F, class... Args>
     explicit Thread(Suite& s, F&& f, Args&&... args) : s_(&s)
     {
-        std::function<void(void)> b = std::bind(std::forward<F>(f), std::forward<Args>(args)...);
+        std::function<void(void)> b = [f = std::forward<F>(f),
+                                       ... args = std::forward<Args>(args)]() mutable {
+            std::invoke(f, args...);
+        };
         t_ = std::thread(&Thread::run, this, std::move(b));
     }
 
diff --git a/include/xrpl/beast/utility/Zero.h b/include/xrpl/beast/utility/Zero.h
index f54345d437..e28589760b 100644
--- a/include/xrpl/beast/utility/Zero.h
+++ b/include/xrpl/beast/utility/Zero.h
@@ -26,9 +26,7 @@ struct Zero
     explicit Zero() = default;
 };
 
-namespace {
-constexpr Zero kZero{};
-}  // namespace
+inline constexpr Zero kZero{};
 
 /** Default implementation of signum calls the method on the class. */
 template <typename T>
diff --git a/include/xrpl/beast/utility/rngfill.h b/include/xrpl/beast/utility/rngfill.h
index ee7a5e2434..5bd9d8bc5c 100644
--- a/include/xrpl/beast/utility/rngfill.h
+++ b/include/xrpl/beast/utility/rngfill.h
@@ -3,7 +3,6 @@
 #include <array>
 #include <cstdint>
 #include <cstring>
-#include <type_traits>
 
 namespace beast {
 
@@ -33,12 +32,10 @@ rngfill(void* const buffer, std::size_t const bytes, Generator& g)
     }
 }
 
-template <
-    class Generator,
-    std::size_t N,
-    class = std::enable_if_t<N % sizeof(typename Generator::result_type) == 0>>
+template <class Generator, std::size_t N>
 void
 rngfill(std::array<std::uint8_t, N>& a, Generator& g)
+    requires(N % sizeof(typename Generator::result_type) == 0)
 {
     using result_type = Generator::result_type;
     auto i = N / sizeof(result_type);
diff --git a/include/xrpl/core/HashRouter.h b/include/xrpl/core/HashRouter.h
index ef8f24d43c..dad1afb405 100644
--- a/include/xrpl/core/HashRouter.h
+++ b/include/xrpl/core/HashRouter.h
@@ -127,7 +127,7 @@ private:
         }
 
         [[nodiscard]] HashRouterFlags
-        getFlags(void) const
+        getFlags() const
         {
             return flags_;
         }
diff --git a/include/xrpl/core/JobQueue.h b/include/xrpl/core/JobQueue.h
index 14170a39be..e4b64546f3 100644
--- a/include/xrpl/core/JobQueue.h
+++ b/include/xrpl/core/JobQueue.h
@@ -154,16 +154,14 @@ public:
 
         @param type The type of job.
         @param name Name of the job.
-        @param jobHandler Lambda with signature void (Job&).  Called when the
-       job is executed.
+        @param jobHandler Callable with signature void(). Called when the job is executed.
 
         @return true if jobHandler added to queue.
     */
-    template <
-        typename JobHandler,
-        typename = std::enable_if_t<std::is_same_v<decltype(std::declval<JobHandler&&>()()), void>>>
+    template <typename JobHandler>
     bool
     addJob(JobType type, std::string const& name, JobHandler&& jobHandler)
+        requires(std::is_void_v<std::invoke_result_t<JobHandler>>)
     {
         if (auto optionalCountedJob = jobCounter_.wrap(std::forward<JobHandler>(jobHandler)))
         {
diff --git a/include/xrpl/json/json_reader.h b/include/xrpl/json/json_reader.h
index c1535bfb55..d1e4ada579 100644
--- a/include/xrpl/json/json_reader.h
+++ b/include/xrpl/json/json_reader.h
@@ -154,7 +154,7 @@ private:
         Location end,
         unsigned int& unicode);
     bool
-    addError(std::string const& message, Token& token, Location extra = 0);
+    addError(std::string const& message, Token& token, Location extra = nullptr);
     bool
     recoverFromError(TokenType skipUntilToken);
     bool
diff --git a/include/xrpl/ledger/OpenView.h b/include/xrpl/ledger/OpenView.h
index de81787906..875909715c 100644
--- a/include/xrpl/ledger/OpenView.h
+++ b/include/xrpl/ledger/OpenView.h
@@ -82,7 +82,7 @@ private:
     using txs_map = std::map<
         key_type,
         TxData,
-        std::less<key_type>,
+        std::less<>,
         boost::container::pmr::polymorphic_allocator<std::pair<key_type const, TxData>>>;
 
     // monotonic_resource_ must outlive `items_`. Make a pointer so it may be
diff --git a/include/xrpl/ledger/detail/RawStateTable.h b/include/xrpl/ledger/detail/RawStateTable.h
index cfa528d355..2e36a42eaf 100644
--- a/include/xrpl/ledger/detail/RawStateTable.h
+++ b/include/xrpl/ledger/detail/RawStateTable.h
@@ -105,7 +105,7 @@ private:
     using items_t = std::map<
         key_type,
         SleAction,
-        std::less<key_type>,
+        std::less<>,
         boost::container::pmr::polymorphic_allocator<std::pair<key_type const, SleAction>>>;
     // monotonic_resource_ must outlive `items_`. Make a pointer so it may be
     // easily moved.
diff --git a/include/xrpl/ledger/helpers/DirectoryHelpers.h b/include/xrpl/ledger/helpers/DirectoryHelpers.h
index 76a5f3bdad..a95b9bc95a 100644
--- a/include/xrpl/ledger/helpers/DirectoryHelpers.h
+++ b/include/xrpl/ledger/helpers/DirectoryHelpers.h
@@ -19,11 +19,7 @@ namespace xrpl {
 
 namespace detail {
 
-template <
-    class V,
-    class N,
-    class = std::enable_if_t<
-        std::is_same_v<std::remove_cv_t<N>, SLE> && std::is_base_of_v<ReadView, V>>>
+template <class V, class N>
 bool
 internalDirNext(
     V& view,
@@ -31,6 +27,7 @@ internalDirNext(
     std::shared_ptr<N>& page,
     unsigned int& index,
     uint256& entry)
+    requires(std::is_same_v<std::remove_cv_t<N>, SLE> && std::is_base_of_v<ReadView, V>)
 {
     auto const& svIndexes = page->getFieldV256(sfIndexes);
     XRPL_ASSERT(index <= svIndexes.size(), "xrpl::detail::internalDirNext : index inside range");
@@ -68,11 +65,7 @@ internalDirNext(
     return true;
 }
 
-template <
-    class V,
-    class N,
-    class = std::enable_if_t<
-        std::is_same_v<std::remove_cv_t<N>, SLE> && std::is_base_of_v<ReadView, V>>>
+template <class V, class N>
 bool
 internalDirFirst(
     V& view,
@@ -80,6 +73,7 @@ internalDirFirst(
     std::shared_ptr<N>& page,
     unsigned int& index,
     uint256& entry)
+    requires(std::is_same_v<std::remove_cv_t<N>, SLE> && std::is_base_of_v<ReadView, V>)
 {
     if constexpr (std::is_const_v<N>)
     {
diff --git a/include/xrpl/net/AutoSocket.h b/include/xrpl/net/AutoSocket.h
index 72eaed7439..b98885959d 100644
--- a/include/xrpl/net/AutoSocket.h
+++ b/include/xrpl/net/AutoSocket.h
@@ -120,12 +120,9 @@ public:
             socket_->next_layer().async_receive(
                 boost::asio::buffer(buffer_),
                 boost::asio::socket_base::message_peek,
-                std::bind(
-                    &AutoSocket::handleAutodetect,
-                    this,
-                    cbFunc,
-                    std::placeholders::_1,
-                    std::placeholders::_2));
+                [this, cbFunc](error_code const& ec, size_t bytesTransferred) {
+                    handleAutodetect(cbFunc, ec, bytesTransferred);
+                });
         }
     }
 
diff --git a/include/xrpl/net/HTTPClientSSLContext.h b/include/xrpl/net/HTTPClientSSLContext.h
index 4192455ec9..51b50a084c 100644
--- a/include/xrpl/net/HTTPClientSSLContext.h
+++ b/include/xrpl/net/HTTPClientSSLContext.h
@@ -13,7 +13,6 @@
 #include <openssl/err.h>
 #include <openssl/tls1.h>
 
-#include <functional>
 #include <stdexcept>
 #include <string>
 #include <type_traits>
@@ -84,13 +83,12 @@ public:
      *
      * @return error_code indicating failures, if any
      */
-    template <
-        class T,
-        class = std::enable_if_t<
-            std::is_same_v<T, boost::asio::ssl::stream<boost::asio::ip::tcp::socket>> ||
-            std::is_same_v<T, boost::asio::ssl::stream<boost::asio::ip::tcp::socket&>>>>
+    template <class T>
     boost::system::error_code
     preConnectVerify(T& strm, std::string const& host)
+        requires(
+            std::is_same_v<T, boost::asio::ssl::stream<boost::asio::ip::tcp::socket>> ||
+            std::is_same_v<T, boost::asio::ssl::stream<boost::asio::ip::tcp::socket&>>)
     {
         boost::system::error_code ec;
         if (!SSL_set_tlsext_host_name(strm.native_handle(), host.c_str()))
@@ -104,11 +102,7 @@ public:
         return ec;
     }
 
-    template <
-        class T,
-        class = std::enable_if_t<
-            std::is_same_v<T, boost::asio::ssl::stream<boost::asio::ip::tcp::socket>> ||
-            std::is_same_v<T, boost::asio::ssl::stream<boost::asio::ip::tcp::socket&>>>>
+    template <class T>
     /**
      * @brief invoked after connect/async_connect but before sending data
      * on an ssl stream - to setup name verification.
@@ -118,6 +112,9 @@ public:
      */
     boost::system::error_code
     postConnectVerify(T& strm, std::string const& host)
+        requires(
+            std::is_same_v<T, boost::asio::ssl::stream<boost::asio::ip::tcp::socket>> ||
+            std::is_same_v<T, boost::asio::ssl::stream<boost::asio::ip::tcp::socket&>>)
     {
         boost::system::error_code ec;
 
@@ -127,8 +124,9 @@ public:
             if (!ec)
             {
                 strm.set_verify_callback(
-                    std::bind(
-                        &rfc6125Verify, host, std::placeholders::_1, std::placeholders::_2, j_),
+                    [host, j = j_](bool preverified, boost::asio::ssl::verify_context& ctx) {
+                        return rfc6125Verify(host, preverified, ctx, j);
+                    },
                     ec);
             }
         }
diff --git a/include/xrpl/nodestore/detail/varint.h b/include/xrpl/nodestore/detail/varint.h
index 6102c0cf2d..5a65545d3a 100644
--- a/include/xrpl/nodestore/detail/varint.h
+++ b/include/xrpl/nodestore/detail/varint.h
@@ -68,9 +68,10 @@ readVarint(void const* buf, std::size_t buflen, std::size_t& t)
     return used;
 }
 
-template <class T, std::enable_if_t<std::is_unsigned_v<T>>* = nullptr>
+template <class T>
 std::size_t
 sizeVarint(T v)
+    requires(std::is_unsigned_v<T>)
 {
     std::size_t n = 0;
     do
@@ -100,9 +101,10 @@ writeVarint(void* p0, std::size_t v)
 
 // input stream
 
-template <class T, std::enable_if_t<std::is_same_v<T, varint>>* = nullptr>
+template <class T>
 void
 read(nudb::detail::istream& is, std::size_t& u)
+    requires(std::is_same_v<T, varint>)
 {
     auto p0 = is(1);
     auto p1 = p0;
@@ -113,9 +115,10 @@ read(nudb::detail::istream& is, std::size_t& u)
 
 // output stream
 
-template <class T, std::enable_if_t<std::is_same_v<T, varint>>* = nullptr>
+template <class T>
 void
 write(nudb::detail::ostream& os, std::size_t t)
+    requires(std::is_same_v<T, varint>)
 {
     writeVarint(os.data(sizeVarint(t)), t);
 }
diff --git a/include/xrpl/protocol/STArray.h b/include/xrpl/protocol/STArray.h
index ed39e65026..573bb6dad8 100644
--- a/include/xrpl/protocol/STArray.h
+++ b/include/xrpl/protocol/STArray.h
@@ -32,17 +32,13 @@ public:
     STArray() = default;
     STArray(STArray const&) = default;
 
-    template <
-        class Iter,
-        class = std::enable_if_t<
-            std::is_convertible_v<typename std::iterator_traits<Iter>::reference, STObject>>>
-    explicit STArray(Iter first, Iter last);
+    template <class Iter>
+    explicit STArray(Iter first, Iter last)
+        requires(std::is_convertible_v<typename std::iterator_traits<Iter>::reference, STObject>);
 
-    template <
-        class Iter,
-        class = std::enable_if_t<
-            std::is_convertible_v<typename std::iterator_traits<Iter>::reference, STObject>>>
-    STArray(SField const& f, Iter first, Iter last);
+    template <class Iter>
+    STArray(SField const& f, Iter first, Iter last)
+        requires(std::is_convertible_v<typename std::iterator_traits<Iter>::reference, STObject>);
 
     STArray&
     operator=(STArray const&) = default;
@@ -170,13 +166,17 @@ private:
     friend class detail::STVar;
 };
 
-template <class Iter, class>
-STArray::STArray(Iter first, Iter last) : v_(first, last)
+template <class Iter>
+STArray::STArray(Iter first, Iter last)
+    requires(std::is_convertible_v<typename std::iterator_traits<Iter>::reference, STObject>)
+    : v_(first, last)
 {
 }
 
-template <class Iter, class>
-STArray::STArray(SField const& f, Iter first, Iter last) : STBase(f), v_(first, last)
+template <class Iter>
+STArray::STArray(SField const& f, Iter first, Iter last)
+    requires(std::is_convertible_v<typename std::iterator_traits<Iter>::reference, STObject>)
+    : STBase(f), v_(first, last)
 {
 }
 
diff --git a/include/xrpl/protocol/STObject.h b/include/xrpl/protocol/STObject.h
index a60e8f7fe8..fe5c611648 100644
--- a/include/xrpl/protocol/STObject.h
+++ b/include/xrpl/protocol/STObject.h
@@ -555,9 +555,14 @@ public:
     ValueProxy&
     operator=(ValueProxy const&) = delete;
 
+    // Write-through proxy: assignment sets the referenced field to the given
+    // value, so it intentionally takes the assigned value rather than a
+    // ValueProxy.
     template <class U>
-    std::enable_if_t<std::is_assignable_v<T, U>, ValueProxy&>
-    operator=(U&& u);
+    // NOLINTNEXTLINE(misc-unconventional-assign-operator)
+    ValueProxy&
+    operator=(U&& u)
+        requires(std::is_assignable_v<T, U>);
 
     // Convenience operators for value types supporting
     // arithmetic operations
@@ -691,8 +696,9 @@ public:
     operator=(optional_type const& v);
 
     template <class U>
-    std::enable_if_t<std::is_assignable_v<T, U>, OptionalProxy&>
-    operator=(U&& u);
+    OptionalProxy&
+    operator=(U&& u)
+        requires(std::is_assignable_v<T, U>);
 
 private:
     friend class STObject;
@@ -798,8 +804,10 @@ STObject::Proxy<T>::assign(U&& u)
 
 template <class T>
 template <class U>
-std::enable_if_t<std::is_assignable_v<T, U>, STObject::ValueProxy<T>&>
+// NOLINTNEXTLINE(misc-unconventional-assign-operator)
+STObject::ValueProxy<T>&
 STObject::ValueProxy<T>::operator=(U&& u)
+    requires(std::is_assignable_v<T, U>)
 {
     this->assign(std::forward<U>(u));
     return *this;
@@ -902,8 +910,9 @@ STObject::OptionalProxy<T>::operator=(optional_type const& v) -> OptionalProxy&
 
 template <class T>
 template <class U>
-std::enable_if_t<std::is_assignable_v<T, U>, STObject::OptionalProxy<T>&>
+STObject::OptionalProxy<T>&
 STObject::OptionalProxy<T>::operator=(U&& u)
+    requires(std::is_assignable_v<T, U>)
 {
     this->assign(std::forward<U>(u));
     return *this;
diff --git a/include/xrpl/protocol/TER.h b/include/xrpl/protocol/TER.h
index b29cb11e15..54b081f358 100644
--- a/include/xrpl/protocol/TER.h
+++ b/include/xrpl/protocol/TER.h
@@ -411,7 +411,7 @@ TERtoInt(TECcodes v)
 
 //------------------------------------------------------------------------------
 // Template class that is specific to selected ranges of error codes.  The
-// Trait tells std::enable_if which ranges are allowed.
+// Trait tells the requires-clause which ranges are allowed.
 template <template <typename> class Trait>
 class TERSubset
 {
@@ -437,11 +437,11 @@ public:
         return TERSubset(from);
     }
 
-    // Trait tells enable_if which types are allowed for construction.
-    template <
-        typename T,
-        typename = std::enable_if_t<Trait<std::remove_cv_t<std::remove_reference_t<T>>>::value>>
-    constexpr TERSubset(T rhs) : code_(TERtoInt(rhs))
+    // Trait tells the requires-clause which types are allowed for construction.
+    template <typename T>
+    constexpr TERSubset(T rhs)
+        requires(Trait<std::remove_cv_t<std::remove_reference_t<T>>>::value)
+        : code_(TERtoInt(rhs))
     {
     }
 
@@ -451,10 +451,11 @@ public:
     constexpr TERSubset&
     operator=(TERSubset&& rhs) = default;
 
-    // Trait tells enable_if which types are allowed for assignment.
+    // Trait tells the requires-clause which types are allowed for assignment.
     template <typename T>
     constexpr auto
-    operator=(T rhs) -> std::enable_if_t<Trait<T>::value, TERSubset&>
+    operator=(T rhs) -> TERSubset&
+        requires(Trait<T>::value)
     {
         code_ = TERtoInt(rhs);
         return *this;
@@ -508,54 +509,60 @@ public:
 // Only enabled if both arguments return int if TERtiInt is called with them.
 template <typename L, typename R>
 constexpr auto
-operator==(L const& lhs, R const& rhs) -> std::enable_if_t<
-    std::is_same_v<decltype(TERtoInt(lhs)), int> && std::is_same_v<decltype(TERtoInt(rhs)), int>,
-    bool>
+operator==(L const& lhs, R const& rhs) -> bool
+    requires(
+        std::is_same_v<decltype(TERtoInt(lhs)), int> &&
+        std::is_same_v<decltype(TERtoInt(rhs)), int>)
 {
     return TERtoInt(lhs) == TERtoInt(rhs);
 }
 
 template <typename L, typename R>
 constexpr auto
-operator!=(L const& lhs, R const& rhs) -> std::enable_if_t<
-    std::is_same_v<decltype(TERtoInt(lhs)), int> && std::is_same_v<decltype(TERtoInt(rhs)), int>,
-    bool>
+operator!=(L const& lhs, R const& rhs) -> bool
+    requires(
+        std::is_same_v<decltype(TERtoInt(lhs)), int> &&
+        std::is_same_v<decltype(TERtoInt(rhs)), int>)
 {
     return TERtoInt(lhs) != TERtoInt(rhs);
 }
 
 template <typename L, typename R>
 constexpr auto
-operator<(L const& lhs, R const& rhs) -> std::enable_if_t<
-    std::is_same_v<decltype(TERtoInt(lhs)), int> && std::is_same_v<decltype(TERtoInt(rhs)), int>,
-    bool>
+operator<(L const& lhs, R const& rhs) -> bool
+    requires(
+        std::is_same_v<decltype(TERtoInt(lhs)), int> &&
+        std::is_same_v<decltype(TERtoInt(rhs)), int>)
 {
     return TERtoInt(lhs) < TERtoInt(rhs);
 }
 
 template <typename L, typename R>
 constexpr auto
-operator<=(L const& lhs, R const& rhs) -> std::enable_if_t<
-    std::is_same_v<decltype(TERtoInt(lhs)), int> && std::is_same_v<decltype(TERtoInt(rhs)), int>,
-    bool>
+operator<=(L const& lhs, R const& rhs) -> bool
+    requires(
+        std::is_same_v<decltype(TERtoInt(lhs)), int> &&
+        std::is_same_v<decltype(TERtoInt(rhs)), int>)
 {
     return TERtoInt(lhs) <= TERtoInt(rhs);
 }
 
 template <typename L, typename R>
 constexpr auto
-operator>(L const& lhs, R const& rhs) -> std::enable_if_t<
-    std::is_same_v<decltype(TERtoInt(lhs)), int> && std::is_same_v<decltype(TERtoInt(rhs)), int>,
-    bool>
+operator>(L const& lhs, R const& rhs) -> bool
+    requires(
+        std::is_same_v<decltype(TERtoInt(lhs)), int> &&
+        std::is_same_v<decltype(TERtoInt(rhs)), int>)
 {
     return TERtoInt(lhs) > TERtoInt(rhs);
 }
 
 template <typename L, typename R>
 constexpr auto
-operator>=(L const& lhs, R const& rhs) -> std::enable_if_t<
-    std::is_same_v<decltype(TERtoInt(lhs)), int> && std::is_same_v<decltype(TERtoInt(rhs)), int>,
-    bool>
+operator>=(L const& lhs, R const& rhs) -> bool
+    requires(
+        std::is_same_v<decltype(TERtoInt(lhs)), int> &&
+        std::is_same_v<decltype(TERtoInt(rhs)), int>)
 {
     return TERtoInt(lhs) >= TERtoInt(rhs);
 }
diff --git a/include/xrpl/resource/detail/Logic.h b/include/xrpl/resource/detail/Logic.h
index 6b1c5e7397..78cd0ac36c 100644
--- a/include/xrpl/resource/detail/Logic.h
+++ b/include/xrpl/resource/detail/Logic.h
@@ -351,10 +351,9 @@ public:
             Import& import(iter->second);
             if (iter->second.whenExpires <= elapsed)
             {
-                for (auto itemIter(import.items.begin()); itemIter != import.items.end();
-                     ++itemIter)
+                for (auto& item : import.items)
                 {
-                    itemIter->consumer.entry().remoteBalance -= itemIter->balance;
+                    item.consumer.entry().remoteBalance -= item.balance;
                 }
 
                 iter = importTable_.erase(iter);
diff --git a/include/xrpl/server/Manifest.h b/include/xrpl/server/Manifest.h
index eb625d220a..c58c784de3 100644
--- a/include/xrpl/server/Manifest.h
+++ b/include/xrpl/server/Manifest.h
@@ -161,13 +161,12 @@ deserializeManifest(
     return deserializeManifest(makeSlice(s), journal);
 }
 
-template <
-    class T,
-    class = std::enable_if_t<std::is_same_v<T, char> || std::is_same_v<T, unsigned char>>>
+template <class T>
 std::optional<Manifest>
 deserializeManifest(
     std::vector<T> const& v,
     beast::Journal journal = beast::Journal(beast::Journal::getNullSink()))
+    requires(std::is_same_v<T, char> || std::is_same_v<T, unsigned char>)
 {
     return deserializeManifest(makeSlice(v), journal);
 }
diff --git a/include/xrpl/server/detail/BaseHTTPPeer.h b/include/xrpl/server/detail/BaseHTTPPeer.h
index f096d3c5a9..7b35dbd4be 100644
--- a/include/xrpl/server/detail/BaseHTTPPeer.h
+++ b/include/xrpl/server/detail/BaseHTTPPeer.h
@@ -223,10 +223,7 @@ BaseHTTPPeer<Handler, Impl>::close()
 {
     if (!strand_.running_in_this_thread())
     {
-        return post(
-            strand_,
-            std::bind(
-                (void (BaseHTTPPeer::*)(void))&BaseHTTPPeer::close, impl().shared_from_this()));
+        return post(strand_, [self = impl().shared_from_this()] { self->close(); });
     }
     boost::beast::get_lowest_layer(impl().stream_).close();
 }
@@ -322,22 +319,18 @@ BaseHTTPPeer<Handler, Impl>::onWrite(error_code const& ec, std::size_t bytesTran
             v,
             bind_executor(
                 strand_,
-                std::bind(
-                    &BaseHTTPPeer::onWrite,
-                    impl().shared_from_this(),
-                    std::placeholders::_1,
-                    std::placeholders::_2)));
+                [self = impl().shared_from_this()](
+                    error_code const& ec, std::size_t bytesTransferred) {
+                    self->onWrite(ec, bytesTransferred);
+                }));
     }
     if (!complete_)
         return;
     if (graceful_)
         return doClose();
-    util::spawn(
-        strand_,
-        std::bind(
-            &BaseHTTPPeer<Handler, Impl>::doRead,
-            impl().shared_from_this(),
-            std::placeholders::_1));
+    util::spawn(strand_, [self = impl().shared_from_this()](yield_context doYield) {
+        self->doRead(doYield);
+    });
 }
 
 template <class Handler, class Impl>
@@ -351,14 +344,9 @@ BaseHTTPPeer<Handler, Impl>::doWriter(
     {
         auto const p = impl().shared_from_this();
         resume = std::function<void(void)>([this, p, writer, keepAlive]() {
-            util::spawn(
-                strand_,
-                std::bind(
-                    &BaseHTTPPeer<Handler, Impl>::doWriter,
-                    p,
-                    writer,
-                    keepAlive,
-                    std::placeholders::_1));
+            util::spawn(strand_, [p, writer, keepAlive](yield_context doYield) {
+                p->doWriter(writer, keepAlive, doYield);
+            });
         });
     }
 
@@ -379,12 +367,9 @@ BaseHTTPPeer<Handler, Impl>::doWriter(
     if (!keepAlive)
         return doClose();
 
-    util::spawn(
-        strand_,
-        std::bind(
-            &BaseHTTPPeer<Handler, Impl>::doRead,
-            impl().shared_from_this(),
-            std::placeholders::_1));
+    util::spawn(strand_, [self = impl().shared_from_this()](yield_context doYield) {
+        self->doRead(doYield);
+    });
 }
 
 //------------------------------------------------------------------------------
@@ -405,8 +390,7 @@ BaseHTTPPeer<Handler, Impl>::write(void const* buf, std::size_t bytes)
         if (!strand_.running_in_this_thread())
         {
             return post(
-                strand_,
-                std::bind(&BaseHTTPPeer::onWrite, impl().shared_from_this(), error_code{}, 0));
+                strand_, [self = impl().shared_from_this()] { self->onWrite(error_code{}, 0); });
         }
         return onWrite(error_code{}, 0);
     }
@@ -417,13 +401,9 @@ void
 BaseHTTPPeer<Handler, Impl>::write(std::shared_ptr<Writer> const& writer, bool keepAlive)
 {
     util::spawn(
-        strand_,
-        std::bind(
-            &BaseHTTPPeer<Handler, Impl>::doWriter,
-            impl().shared_from_this(),
-            writer,
-            keepAlive,
-            std::placeholders::_1));
+        strand_, [self = impl().shared_from_this(), writer, keepAlive](yield_context doYield) {
+            self->doWriter(writer, keepAlive, doYield);
+        });
 }
 
 // DEPRECATED
@@ -443,8 +423,7 @@ BaseHTTPPeer<Handler, Impl>::complete()
 {
     if (!strand_.running_in_this_thread())
     {
-        return post(
-            strand_, std::bind(&BaseHTTPPeer<Handler, Impl>::complete, impl().shared_from_this()));
+        return post(strand_, [self = impl().shared_from_this()] { self->complete(); });
     }
 
     message_ = {};
@@ -457,12 +436,9 @@ BaseHTTPPeer<Handler, Impl>::complete()
     }
 
     // keep-alive
-    util::spawn(
-        strand_,
-        std::bind(
-            &BaseHTTPPeer<Handler, Impl>::doRead,
-            impl().shared_from_this(),
-            std::placeholders::_1));
+    util::spawn(strand_, [self = impl().shared_from_this()](yield_context doYield) {
+        self->doRead(doYield);
+    });
 }
 
 // DEPRECATED
@@ -474,11 +450,7 @@ BaseHTTPPeer<Handler, Impl>::close(bool graceful)
     if (!strand_.running_in_this_thread())
     {
         return post(
-            strand_,
-            std::bind(
-                (void (BaseHTTPPeer::*)(bool))&BaseHTTPPeer<Handler, Impl>::close,
-                impl().shared_from_this(),
-                graceful));
+            strand_, [self = impl().shared_from_this(), graceful] { self->close(graceful); });
     }
 
     complete_ = true;
diff --git a/include/xrpl/server/detail/BasePeer.h b/include/xrpl/server/detail/BasePeer.h
index 5301a2f018..84aa1e0da9 100644
--- a/include/xrpl/server/detail/BasePeer.h
+++ b/include/xrpl/server/detail/BasePeer.h
@@ -10,7 +10,6 @@
 
 #include <atomic>
 #include <chrono>
-#include <functional>
 #include <string>
 #include <utility>
 
@@ -84,7 +83,7 @@ void
 BasePeer<Handler, Impl>::close()
 {
     if (!strand_.running_in_this_thread())
-        return post(strand_, std::bind(&BasePeer::close, impl().shared_from_this()));
+        return post(strand_, [self = impl().shared_from_this()] { self->close(); });
     error_code ec;
     xrpl::getLowestLayer(impl().ws_).socket().close(ec);
 }
diff --git a/include/xrpl/server/detail/BaseWSPeer.h b/include/xrpl/server/detail/BaseWSPeer.h
index 1b6a9faca3..d557140bd4 100644
--- a/include/xrpl/server/detail/BaseWSPeer.h
+++ b/include/xrpl/server/detail/BaseWSPeer.h
@@ -20,6 +20,7 @@
 
 #include <algorithm>
 #include <chrono>
+#include <cstddef>
 #include <functional>
 #include <iterator>
 #include <list>
@@ -180,12 +181,13 @@ void
 BaseWSPeer<Handler, Impl>::run()
 {
     if (!strand_.running_in_this_thread())
-        return post(strand_, std::bind(&BaseWSPeer::run, impl().shared_from_this()));
+        return post(strand_, [self = impl().shared_from_this()] { self->run(); });
     impl().ws_.set_option(port().pmdOptions);
     // Must manage the control callback memory outside of the `control_callback`
     // function
-    controlCallback_ =
-        std::bind(&BaseWSPeer::onPingPong, this, std::placeholders::_1, std::placeholders::_2);
+    controlCallback_ = [this](
+                           boost::beast::websocket::frame_type kind,
+                           boost::beast::string_view payload) { onPingPong(kind, payload); };
     impl().ws_.control_callback(controlCallback_);
     startTimer();
     closeOnTimer_ = true;
@@ -193,11 +195,9 @@ BaseWSPeer<Handler, Impl>::run()
         res.set(boost::beast::http::field::server, BuildInfo::getFullVersionString());
     }));
     impl().ws_.async_accept(
-        request_,
-        bind_executor(
-            strand_,
-            std::bind(
-                &BaseWSPeer::onWsHandshake, impl().shared_from_this(), std::placeholders::_1)));
+        request_, bind_executor(strand_, [self = impl().shared_from_this()](error_code const& ec) {
+            self->onWsHandshake(ec);
+        }));
 }
 
 template <class Handler, class Impl>
@@ -205,7 +205,10 @@ void
 BaseWSPeer<Handler, Impl>::send(std::shared_ptr<WSMsg> w)
 {
     if (!strand_.running_in_this_thread())
-        return post(strand_, std::bind(&BaseWSPeer::send, impl().shared_from_this(), std::move(w)));
+    {
+        return post(
+            strand_, [self = impl().shared_from_this(), w = std::move(w)] { self->send(w); });
+    }
     if (doClose_)
         return;
     if (wq_.size() > port().wsQueueLimit)
@@ -258,7 +261,7 @@ void
 BaseWSPeer<Handler, Impl>::complete()
 {
     if (!strand_.running_in_this_thread())
-        return post(strand_, std::bind(&BaseWSPeer::complete, impl().shared_from_this()));
+        return post(strand_, [self = impl().shared_from_this()] { self->complete(); });
     doRead();
 }
 
@@ -277,7 +280,7 @@ void
 BaseWSPeer<Handler, Impl>::doWrite()
 {
     if (!strand_.running_in_this_thread())
-        return post(strand_, std::bind(&BaseWSPeer::doWrite, impl().shared_from_this()));
+        return post(strand_, [self = impl().shared_from_this()] { self->doWrite(); });
     onWrite({});
 }
 
@@ -288,8 +291,7 @@ BaseWSPeer<Handler, Impl>::onWrite(error_code const& ec)
     if (ec)
         return fail(ec, "write");
     auto& w = *wq_.front();
-    auto const result =
-        w.prepare(65536, std::bind(&BaseWSPeer::doWrite, impl().shared_from_this()));
+    auto const result = w.prepare(65536, [self = impl().shared_from_this()] { self->doWrite(); });
     if (boost::indeterminate(result.first))
         return;
     startTimer();
@@ -299,8 +301,9 @@ BaseWSPeer<Handler, Impl>::onWrite(error_code const& ec)
             static_cast<bool>(result.first),
             result.second,
             bind_executor(
-                strand_,
-                std::bind(&BaseWSPeer::onWrite, impl().shared_from_this(), std::placeholders::_1)));
+                strand_, [self = impl().shared_from_this()](error_code const& ec, std::size_t) {
+                    self->onWrite(ec);
+                }));
     }
     else
     {
@@ -308,9 +311,9 @@ BaseWSPeer<Handler, Impl>::onWrite(error_code const& ec)
             static_cast<bool>(result.first),
             result.second,
             bind_executor(
-                strand_,
-                std::bind(
-                    &BaseWSPeer::onWriteFin, impl().shared_from_this(), std::placeholders::_1)));
+                strand_, [self = impl().shared_from_this()](error_code const& ec, std::size_t) {
+                    self->onWriteFin(ec);
+                }));
     }
 }
 
@@ -324,10 +327,9 @@ BaseWSPeer<Handler, Impl>::onWriteFin(error_code const& ec)
     if (doClose_)
     {
         impl().ws_.async_close(
-            cr_,
-            bind_executor(
-                strand_,
-                std::bind(&BaseWSPeer::onClose, impl().shared_from_this(), std::placeholders::_1)));
+            cr_, bind_executor(strand_, [self = impl().shared_from_this()](error_code const& ec) {
+                self->onClose(ec);
+            }));
     }
     else if (!wq_.empty())
     {
@@ -340,12 +342,13 @@ void
 BaseWSPeer<Handler, Impl>::doRead()
 {
     if (!strand_.running_in_this_thread())
-        return post(strand_, std::bind(&BaseWSPeer::doRead, impl().shared_from_this()));
+        return post(strand_, [self = impl().shared_from_this()] { self->doRead(); });
     impl().ws_.async_read(
         rb_,
         bind_executor(
-            strand_,
-            std::bind(&BaseWSPeer::onRead, impl().shared_from_this(), std::placeholders::_1)));
+            strand_, [self = impl().shared_from_this()](error_code const& ec, std::size_t) {
+                self->onRead(ec);
+            }));
 }
 
 template <class Handler, class Impl>
@@ -389,11 +392,7 @@ BaseWSPeer<Handler, Impl>::startTimer()
     }
 
     timer_.async_wait(bind_executor(
-        strand_,
-        std::bind(
-            &BaseWSPeer<Handler, Impl>::onTimer,
-            impl().shared_from_this(),
-            std::placeholders::_1)));
+        strand_, [self = impl().shared_from_this()](error_code const& ec) { self->onTimer(ec); }));
 }
 
 // Convenience for discarding the error code
@@ -461,10 +460,9 @@ BaseWSPeer<Handler, Impl>::onTimer(error_code ec)
             beast::rngfill(payload_.begin(), payload_.size(), cryptoPrng());
             impl().ws_.async_ping(
                 payload_,
-                bind_executor(
-                    strand_,
-                    std::bind(
-                        &BaseWSPeer::onPing, impl().shared_from_this(), std::placeholders::_1)));
+                bind_executor(strand_, [self = impl().shared_from_this()](error_code const& ec) {
+                    self->onPing(ec);
+                }));
             JLOG(this->j_.trace()) << "sent ping";
             return;
         }
diff --git a/include/xrpl/server/detail/Door.h b/include/xrpl/server/detail/Door.h
index 09b0adc5f2..d2d7a7baf4 100644
--- a/include/xrpl/server/detail/Door.h
+++ b/include/xrpl/server/detail/Door.h
@@ -33,7 +33,6 @@
 #include <algorithm>
 #include <chrono>
 #include <cstdint>
-#include <functional>
 #include <memory>
 #include <optional>
 #include <sstream>
@@ -182,7 +181,7 @@ void
 Door<Handler>::Detector::run()
 {
     util::spawn(
-        strand_, std::bind(&Detector::doDetect, this->shared_from_this(), std::placeholders::_1));
+        strand_, [self = this->shared_from_this()](yield_context yield) { self->doDetect(yield); });
 }
 
 template <class Handler>
@@ -297,8 +296,7 @@ void
 Door<Handler>::run()
 {
     util::spawn(
-        strand_,
-        std::bind(&Door<Handler>::doAccept, this->shared_from_this(), std::placeholders::_1));
+        strand_, [self = this->shared_from_this()](yield_context yield) { self->doAccept(yield); });
 }
 
 template <class Handler>
@@ -307,8 +305,7 @@ Door<Handler>::close()
 {
     if (!strand_.running_in_this_thread())
     {
-        return boost::asio::post(
-            strand_, std::bind(&Door<Handler>::close, this->shared_from_this()));
+        return boost::asio::post(strand_, [self = this->shared_from_this()] { self->close(); });
     }
     backoffTimer_.cancel();
     error_code ec;
diff --git a/include/xrpl/server/detail/PlainHTTPPeer.h b/include/xrpl/server/detail/PlainHTTPPeer.h
index b89272fe9e..688fbbd425 100644
--- a/include/xrpl/server/detail/PlainHTTPPeer.h
+++ b/include/xrpl/server/detail/PlainHTTPPeer.h
@@ -9,7 +9,6 @@
 
 #include <boost/beast/core/tcp_stream.hpp>
 
-#include <functional>
 #include <memory>
 #include <utility>
 
@@ -89,7 +88,9 @@ PlainHTTPPeer<Handler>::run()
 {
     if (!this->handler_.onAccept(this->session(), this->remoteAddress_))
     {
-        util::spawn(this->strand_, std::bind(&PlainHTTPPeer::doClose, this->shared_from_this()));
+        util::spawn(this->strand_, [self = this->shared_from_this()](boost::asio::yield_context) {
+            self->doClose();
+        });
         return;
     }
 
@@ -97,8 +98,9 @@ PlainHTTPPeer<Handler>::run()
         return;
 
     util::spawn(
-        this->strand_,
-        std::bind(&PlainHTTPPeer::doRead, this->shared_from_this(), std::placeholders::_1));
+        this->strand_, [self = this->shared_from_this()](boost::asio::yield_context doYield) {
+            self->doRead(doYield);
+        });
 }
 
 template <class Handler>
diff --git a/include/xrpl/server/detail/SSLHTTPPeer.h b/include/xrpl/server/detail/SSLHTTPPeer.h
index ea2108b917..7fe21ed6b5 100644
--- a/include/xrpl/server/detail/SSLHTTPPeer.h
+++ b/include/xrpl/server/detail/SSLHTTPPeer.h
@@ -13,7 +13,6 @@
 #include <boost/beast/core/tcp_stream.hpp>
 #include <boost/beast/ssl/ssl_stream.hpp>
 
-#include <functional>
 #include <memory>
 #include <utility>
 
@@ -99,14 +98,15 @@ SSLHTTPPeer<Handler>::run()
 {
     if (!this->handler_.onAccept(this->session(), this->remoteAddress_))
     {
-        util::spawn(this->strand_, std::bind(&SSLHTTPPeer::doClose, this->shared_from_this()));
+        util::spawn(
+            this->strand_, [self = this->shared_from_this()](yield_context) { self->doClose(); });
         return;
     }
     if (!socket_.is_open())
         return;
-    util::spawn(
-        this->strand_,
-        std::bind(&SSLHTTPPeer::doHandshake, this->shared_from_this(), std::placeholders::_1));
+    util::spawn(this->strand_, [self = this->shared_from_this()](yield_context doYield) {
+        self->doHandshake(doYield);
+    });
 }
 
 template <class Handler>
@@ -142,9 +142,9 @@ SSLHTTPPeer<Handler>::doHandshake(yield_context doYield)
         this->port().protocol.count("https") > 0;
     if (http)
     {
-        util::spawn(
-            this->strand_,
-            std::bind(&SSLHTTPPeer::doRead, this->shared_from_this(), std::placeholders::_1));
+        util::spawn(this->strand_, [self = this->shared_from_this()](yield_context doYield) {
+            self->doRead(doYield);
+        });
         return;
     }
     // `this` will be destroyed
@@ -172,7 +172,7 @@ SSLHTTPPeer<Handler>::doClose()
     this->startTimer();
     stream_.async_shutdown(bind_executor(
         this->strand_,
-        std::bind(&SSLHTTPPeer::onShutdown, this->shared_from_this(), std::placeholders::_1)));
+        [self = this->shared_from_this()](error_code const& ec) { self->onShutdown(ec); }));
 }
 
 template <class Handler>
diff --git a/include/xrpl/shamap/FullBelowCache.h b/include/xrpl/shamap/FullBelowCache.h
index dc597278df..b6d1142eb4 100644
--- a/include/xrpl/shamap/FullBelowCache.h
+++ b/include/xrpl/shamap/FullBelowCache.h
@@ -103,7 +103,7 @@ public:
 
     /** generation determines whether cached entry is valid */
     std::uint32_t
-    getGeneration(void) const
+    getGeneration() const
     {
         return gen_;
     }
diff --git a/src/libxrpl/basics/ResolverAsio.cpp b/src/libxrpl/basics/ResolverAsio.cpp
index ddf006b681..7e1b56f87a 100644
--- a/src/libxrpl/basics/ResolverAsio.cpp
+++ b/src/libxrpl/basics/ResolverAsio.cpp
@@ -192,7 +192,7 @@ public:
             boost::asio::dispatch(
                 ioContext,
                 boost::asio::bind_executor(
-                    strand, std::bind(&ResolverAsioImpl::doStop, this, CompletionCounter(this))));
+                    strand, [this, counter = CompletionCounter(this)] { doStop(counter); }));
 
             JLOG(journal.debug()) << "Queued a stop request";
         }
@@ -221,9 +221,9 @@ public:
         boost::asio::dispatch(
             ioContext,
             boost::asio::bind_executor(
-                strand,
-                std::bind(
-                    &ResolverAsioImpl::doResolve, this, names, handler, CompletionCounter(this))));
+                strand, [this, names, handler, counter = CompletionCounter(this)] {
+                    doResolve(names, handler, counter);
+                }));
     }
 
     //-------------------------------------------------------------------------
@@ -272,7 +272,7 @@ public:
         boost::asio::post(
             ioContext,
             boost::asio::bind_executor(
-                strand, std::bind(&ResolverAsioImpl::doWork, this, CompletionCounter(this))));
+                strand, [this, counter = CompletionCounter(this)] { doWork(counter); }));
     }
 
     static HostAndPort
@@ -291,8 +291,10 @@ public:
         // a port separator
 
         // Attempt to find the first and last non-whitespace
-        auto const findWhitespace =
-            std::bind(&std::isspace<std::string::value_type>, std::placeholders::_1, std::locale());
+        std::locale const loc;
+        auto const findWhitespace = [&loc](std::string::value_type c) {
+            return std::isspace<std::string::value_type>(c, loc);
+        };
 
         auto hostFirst = std::ranges::find_if_not(str, findWhitespace);
 
@@ -348,7 +350,7 @@ public:
             boost::asio::post(
                 ioContext,
                 boost::asio::bind_executor(
-                    strand, std::bind(&ResolverAsioImpl::doWork, this, CompletionCounter(this))));
+                    strand, [this, counter = CompletionCounter(this)] { doWork(counter); }));
 
             return;
         }
@@ -356,14 +358,11 @@ public:
         resolver.async_resolve(
             host,
             port,
-            std::bind(
-                &ResolverAsioImpl::doFinish,
-                this,
-                name,
-                std::placeholders::_1,
-                handler,
-                std::placeholders::_2,
-                CompletionCounter(this)));
+            [this, name, handler, counter = CompletionCounter(this)](
+                boost::system::error_code const& ec,
+                boost::asio::ip::tcp::resolver::results_type results) {
+                doFinish(name, ec, handler, results, counter);
+            });
     }
 
     void
@@ -383,8 +382,7 @@ public:
                 boost::asio::post(
                     ioContext,
                     boost::asio::bind_executor(
-                        strand,
-                        std::bind(&ResolverAsioImpl::doWork, this, CompletionCounter(this))));
+                        strand, [this, counter = CompletionCounter(this)] { doWork(counter); }));
             }
         }
     }
diff --git a/src/libxrpl/beast/insight/StatsDCollector.cpp b/src/libxrpl/beast/insight/StatsDCollector.cpp
index 1da5315de1..3cff5d93b5 100644
--- a/src/libxrpl/beast/insight/StatsDCollector.cpp
+++ b/src/libxrpl/beast/insight/StatsDCollector.cpp
@@ -325,9 +325,9 @@ public:
     postBuffer(std::string&& buffer)
     {
         boost::asio::dispatch(
-            ioContext_,
-            boost::asio::bind_executor(
-                strand_, std::bind(&StatsDCollectorImp::doPostBuffer, this, std::move(buffer))));
+            ioContext_, boost::asio::bind_executor(strand_, [this, buffer = std::move(buffer)] {
+                doPostBuffer(buffer);
+            }));
     }
 
     // The keepAlive parameter makes sure the buffers sent to
@@ -392,12 +392,10 @@ public:
                 log(buffers);
                 socket_.async_send(
                     buffers,
-                    std::bind(
-                        &StatsDCollectorImp::onSend,
-                        this,
-                        keepAlive,
-                        std::placeholders::_1,
-                        std::placeholders::_2));
+                    [this, keepAlive](
+                        boost::system::error_code const& ec, std::size_t bytesTransferred) {
+                        onSend(keepAlive, ec, bytesTransferred);
+                    });
                 buffers.clear();
                 size = 0;
             }
@@ -411,12 +409,10 @@ public:
             log(buffers);
             socket_.async_send(
                 buffers,
-                std::bind(
-                    &StatsDCollectorImp::onSend,
-                    this,
-                    keepAlive,
-                    std::placeholders::_1,
-                    std::placeholders::_2));
+                [this, keepAlive](
+                    boost::system::error_code const& ec, std::size_t bytesTransferred) {
+                    onSend(keepAlive, ec, bytesTransferred);
+                });
         }
     }
 
@@ -425,7 +421,7 @@ public:
     {
         using namespace std::chrono_literals;
         timer_.expires_after(1s);
-        timer_.async_wait(std::bind(&StatsDCollectorImp::onTimer, this, std::placeholders::_1));
+        timer_.async_wait([this](boost::system::error_code const& ec) { onTimer(ec); });
     }
 
     void
@@ -513,10 +509,9 @@ StatsDCounterImpl::increment(CounterImpl::value_type amount)
 {
     boost::asio::dispatch(
         impl_->getIoContext(),
-        std::bind(
-            &StatsDCounterImpl::doIncrement,
-            std::static_pointer_cast<StatsDCounterImpl>(shared_from_this()),
-            amount));
+        [self = std::static_pointer_cast<StatsDCounterImpl>(shared_from_this()), amount] {
+            self->doIncrement(amount);
+        });
 }
 
 void
@@ -558,10 +553,9 @@ StatsDEventImpl::notify(EventImpl::value_type const& value)
 {
     boost::asio::dispatch(
         impl_->getIoContext(),
-        std::bind(
-            &StatsDEventImpl::doNotify,
-            std::static_pointer_cast<StatsDEventImpl>(shared_from_this()),
-            value));
+        [self = std::static_pointer_cast<StatsDEventImpl>(shared_from_this()), value] {
+            self->doNotify(value);
+        });
 }
 
 void
@@ -591,10 +585,9 @@ StatsDGaugeImpl::set(GaugeImpl::value_type value)
 {
     boost::asio::dispatch(
         impl_->getIoContext(),
-        std::bind(
-            &StatsDGaugeImpl::doSet,
-            std::static_pointer_cast<StatsDGaugeImpl>(shared_from_this()),
-            value));
+        [self = std::static_pointer_cast<StatsDGaugeImpl>(shared_from_this()), value] {
+            self->doSet(value);
+        });
 }
 
 void
@@ -602,10 +595,9 @@ StatsDGaugeImpl::increment(GaugeImpl::difference_type amount)
 {
     boost::asio::dispatch(
         impl_->getIoContext(),
-        std::bind(
-            &StatsDGaugeImpl::doIncrement,
-            std::static_pointer_cast<StatsDGaugeImpl>(shared_from_this()),
-            amount));
+        [self = std::static_pointer_cast<StatsDGaugeImpl>(shared_from_this()), amount] {
+            self->doIncrement(amount);
+        });
 }
 
 void
@@ -678,10 +670,9 @@ StatsDMeterImpl::increment(MeterImpl::value_type amount)
 {
     boost::asio::dispatch(
         impl_->getIoContext(),
-        std::bind(
-            &StatsDMeterImpl::doIncrement,
-            std::static_pointer_cast<StatsDMeterImpl>(shared_from_this()),
-            amount));
+        [self = std::static_pointer_cast<StatsDMeterImpl>(shared_from_this()), amount] {
+            self->doIncrement(amount);
+        });
 }
 
 void
diff --git a/src/libxrpl/core/detail/JobQueue.cpp b/src/libxrpl/core/detail/JobQueue.cpp
index f773270af3..8f95a8a5fa 100644
--- a/src/libxrpl/core/detail/JobQueue.cpp
+++ b/src/libxrpl/core/detail/JobQueue.cpp
@@ -13,7 +13,6 @@
 
 #include <algorithm>
 #include <chrono>
-#include <functional>
 #include <memory>
 #include <mutex>
 #include <set>
@@ -36,7 +35,7 @@ JobQueue::JobQueue(
 {
     JLOG(journal_.info()) << "Using " << threadCount << "  threads";
 
-    hook_ = collector_->makeHook(std::bind(&JobQueue::collect, this));
+    hook_ = collector_->makeHook([this] { collect(); });
     jobCount_ = collector_->makeGauge("job_count");
 
     {
diff --git a/src/libxrpl/json/json_reader.cpp b/src/libxrpl/json/json_reader.cpp
index 45e448c480..a12ec7b565 100644
--- a/src/libxrpl/json/json_reader.cpp
+++ b/src/libxrpl/json/json_reader.cpp
@@ -86,8 +86,8 @@ Reader::parse(char const* beginDoc, char const* endDoc, Value& root)
     begin_ = beginDoc;
     end_ = endDoc;
     current_ = begin_;
-    lastValueEnd_ = 0;
-    lastValue_ = 0;
+    lastValueEnd_ = nullptr;
+    lastValue_ = nullptr;
     errors_.clear();
 
     while (!nodes_.empty())
@@ -908,9 +908,8 @@ Reader::getFormattedErrorMessages() const
 {
     std::string formattedMessage;
 
-    for (auto itError = errors_.begin(); itError != errors_.end(); ++itError)
+    for (auto const& error : errors_)
     {
-        ErrorInfo const& error = *itError;
         formattedMessage += "* " + getLocationLineAndColumn(error.token.start) + "\n";
         formattedMessage += "  " + error.message + "\n";
 
diff --git a/src/libxrpl/json/json_value.cpp b/src/libxrpl/json/json_value.cpp
index 7218b8c6cf..c679e30e16 100644
--- a/src/libxrpl/json/json_value.cpp
+++ b/src/libxrpl/json/json_value.cpp
@@ -90,7 +90,7 @@ static struct DummyValueAllocatorInitializer
 // Notes: index_ indicates if the string was allocated when
 // a string is stored.
 
-Value::CZString::CZString(int index) : cstr_(0), index_(index)
+Value::CZString::CZString(int index) : cstr_(nullptr), index_(index)
 {
 }
 
@@ -103,7 +103,8 @@ Value::CZString::CZString(char const* cstr, DuplicationPolicy allocate)
 
 Value::CZString::CZString(CZString const& other)
     : cstr_(
-          other.index_ != static_cast<int>(DuplicationPolicy::NoDuplication) && other.cstr_ != 0
+          other.index_ != static_cast<int>(DuplicationPolicy::NoDuplication) &&
+                  other.cstr_ != nullptr
               ? valueAllocator()->makeMemberName(other.cstr_)
               : other.cstr_)
     , index_([&]() -> int {
@@ -187,7 +188,7 @@ Value::Value(ValueType type) : type_(type)
             break;
 
         case ValueType::String:
-            value_.stringVal = 0;
+            value_.stringVal = nullptr;
             break;
 
         case ValueType::Array:
@@ -268,7 +269,7 @@ Value::Value(Value const& other) : type_(other.type_)
             }
             else
             {
-                value_.stringVal = 0;
+                value_.stringVal = nullptr;
             }
 
             break;
@@ -405,7 +406,7 @@ operator<(Value const& x, Value const& y)
             return static_cast<int>(x.value_.boolVal) < static_cast<int>(y.value_.boolVal);
 
         case ValueType::String:
-            return (x.value_.stringVal == 0 && (y.value_.stringVal != nullptr)) ||
+            return (x.value_.stringVal == nullptr && (y.value_.stringVal != nullptr)) ||
                 ((y.value_.stringVal != nullptr) && (x.value_.stringVal != nullptr) &&
                  strcmp(x.value_.stringVal, y.value_.stringVal) < 0);
 
diff --git a/src/libxrpl/net/HTTPClient.cpp b/src/libxrpl/net/HTTPClient.cpp
index 4b9cc9d6e6..5edd8b5b47 100644
--- a/src/libxrpl/net/HTTPClient.cpp
+++ b/src/libxrpl/net/HTTPClient.cpp
@@ -134,12 +134,10 @@ public:
         request(
             bSSL,
             deqSites,
-            std::bind(
-                &HTTPClientImp::makeGet,
-                shared_from_this(),
-                strPath,
-                std::placeholders::_1,
-                std::placeholders::_2),
+            [self = shared_from_this(), strPath](
+                boost::asio::streambuf& sb, std::string const& strHost) {
+                self->makeGet(strPath, sb, strHost);
+            },
             timeout,
             complete);
     }
@@ -166,9 +164,9 @@ public:
             shutdown_ = e.code();
 
             JLOG(j_.trace()) << "expires_after: " << shutdown_.message();
-            deadline_.async_wait(
-                std::bind(
-                    &HTTPClientImp::handleDeadline, shared_from_this(), std::placeholders::_1));
+            deadline_.async_wait([self = shared_from_this()](boost::system::error_code const& ec) {
+                self->handleDeadline(ec);
+            });
         }
 
         if (!shutdown_)
@@ -179,11 +177,11 @@ public:
                 query_->host,
                 query_->port,
                 query_->flags,
-                std::bind(
-                    &HTTPClientImp::handleResolve,
-                    shared_from_this(),
-                    std::placeholders::_1,
-                    std::placeholders::_2));
+                [self = shared_from_this()](
+                    boost::system::error_code const& ecResult,
+                    boost::asio::ip::tcp::resolver::results_type results) {
+                    self->handleResolve(ecResult, results);
+                });
         }
 
         if (shutdown_)
@@ -220,9 +218,9 @@ public:
             resolver_.cancel();
 
             // Stop the transaction.
-            socket_.asyncShutdown(
-                std::bind(
-                    &HTTPClientImp::handleShutdown, shared_from_this(), std::placeholders::_1));
+            socket_.asyncShutdown([self = shared_from_this()](boost::system::error_code const& ec) {
+                self->handleShutdown(ec);
+            });
         }
     }
 
@@ -262,8 +260,9 @@ public:
             boost::asio::async_connect(
                 socket_.lowestLayer(),
                 result,
-                std::bind(
-                    &HTTPClientImp::handleConnect, shared_from_this(), std::placeholders::_1));
+                [self = shared_from_this()](
+                    boost::system::error_code const& ecResult,
+                    boost::asio::ip::tcp::endpoint const&) { self->handleConnect(ecResult); });
         }
     }
 
@@ -301,8 +300,9 @@ public:
         {
             socket_.asyncHandshake(
                 AutoSocket::ssl_socket::client,
-                std::bind(
-                    &HTTPClientImp::handleRequest, shared_from_this(), std::placeholders::_1));
+                [self = shared_from_this()](boost::system::error_code const& ec) {
+                    self->handleRequest(ec);
+                });
         }
         else
         {
@@ -330,11 +330,10 @@ public:
 
             socket_.asyncWrite(
                 request_,
-                std::bind(
-                    &HTTPClientImp::handleWrite,
-                    shared_from_this(),
-                    std::placeholders::_1,
-                    std::placeholders::_2));
+                [self = shared_from_this()](
+                    boost::system::error_code const& ecResult, std::size_t bytesTransferred) {
+                    self->handleWrite(ecResult, bytesTransferred);
+                });
         }
     }
 
@@ -357,11 +356,10 @@ public:
             socket_.asyncReadUntil(
                 header_,
                 "\r\n\r\n",
-                std::bind(
-                    &HTTPClientImp::handleHeader,
-                    shared_from_this(),
-                    std::placeholders::_1,
-                    std::placeholders::_2));
+                [self = shared_from_this()](
+                    boost::system::error_code const& ecResult, std::size_t bytesTransferred) {
+                    self->handleHeader(ecResult, bytesTransferred);
+                });
         }
     }
 
@@ -372,10 +370,10 @@ public:
             {std::istreambuf_iterator<char>(&header_)}, std::istreambuf_iterator<char>()};
         JLOG(j_.trace()) << "Header: \"" << strHeader << "\"";
 
-        static boost::regex const kReStatus{"\\`HTTP/1\\S+ (\\d{3}) .*\\'"};  // HTTP/1.1 200 OK
+        static boost::regex const kReStatus{R"(\`HTTP/1\S+ (\d{3}) .*\')"};  // HTTP/1.1 200 OK
         static boost::regex const kReSize{
-            "\\`.*\\r\\nContent-Length:\\s+([0-9]+).*\\'", boost::regex::icase};
-        static boost::regex const kReBody{"\\`.*\\r\\n\\r\\n(.*)\\'"};
+            R"(\`.*\r\nContent-Length:\s+([0-9]+).*\')", boost::regex::icase};
+        static boost::regex const kReBody{R"(\`.*\r\n\r\n(.*)\')"};
 
         boost::smatch smMatch;
         // Match status code.
@@ -424,11 +422,10 @@ public:
             socket_.asyncRead(
                 response_.prepare(responseSize - body_.size()),
                 boost::asio::transfer_all(),
-                std::bind(
-                    &HTTPClientImp::handleData,
-                    shared_from_this(),
-                    std::placeholders::_1,
-                    std::placeholders::_2));
+                [self = shared_from_this()](
+                    boost::system::error_code const& ecResult, std::size_t bytesTransferred) {
+                    self->handleData(ecResult, bytesTransferred);
+                });
         }
     }
 
diff --git a/src/libxrpl/protocol/PublicKey.cpp b/src/libxrpl/protocol/PublicKey.cpp
index c6e6c1d324..97948fcae3 100644
--- a/src/libxrpl/protocol/PublicKey.cpp
+++ b/src/libxrpl/protocol/PublicKey.cpp
@@ -87,11 +87,11 @@ sliceToHex(Slice const& slice)
         s.reserve(2 * (slice.size() + 1));
         s = "0x";
     }
-    for (int i = 0; i < slice.size(); ++i)
+    for (std::uint8_t const byte : slice)
     {
         static constexpr char kHex[] = "0123456789ABCDEF";
-        s += kHex[((slice[i] & 0xf0) >> 4)];
-        s += kHex[((slice[i] & 0x0f) >> 0)];
+        s += kHex[((byte & 0xf0) >> 4)];
+        s += kHex[((byte & 0x0f) >> 0)];
     }
     return s;
 }
diff --git a/src/libxrpl/protocol/STObject.cpp b/src/libxrpl/protocol/STObject.cpp
index ea8553dc4f..869700baed 100644
--- a/src/libxrpl/protocol/STObject.cpp
+++ b/src/libxrpl/protocol/STObject.cpp
@@ -502,7 +502,7 @@ STObject::isFlag(std::uint32_t f) const
 }
 
 std::uint32_t
-STObject::getFlags(void) const
+STObject::getFlags() const
 {
     auto const* t = dynamic_cast<STUInt32 const*>(peekAtPField(sfFlags));
 
diff --git a/src/libxrpl/protocol/STParsedJSON.cpp b/src/libxrpl/protocol/STParsedJSON.cpp
index 64c4dfd1be..d3342ef728 100644
--- a/src/libxrpl/protocol/STParsedJSON.cpp
+++ b/src/libxrpl/protocol/STParsedJSON.cpp
@@ -50,8 +50,9 @@ namespace xrpl {
 
 namespace STParsedJSONDetail {
 template <typename U, typename S>
-constexpr std::enable_if_t<std::is_unsigned_v<U> && std::is_signed_v<S>, U>
+constexpr U
 toUnsigned(S value)
+    requires(std::is_unsigned_v<U> && std::is_signed_v<S>)
 {
     if (value < 0 || std::numeric_limits<U>::max() < value)
         Throw<std::runtime_error>("Value out of range");
@@ -59,8 +60,9 @@ toUnsigned(S value)
 }
 
 template <typename U1, typename U2>
-constexpr std::enable_if_t<std::is_unsigned_v<U1> && std::is_unsigned_v<U2>, U1>
+constexpr U1
 toUnsigned(U2 value)
+    requires(std::is_unsigned_v<U1> && std::is_unsigned_v<U2>)
 {
     if (std::numeric_limits<U1>::max() < value)
         Throw<std::runtime_error>("Value out of range");
diff --git a/src/libxrpl/protocol/STTx.cpp b/src/libxrpl/protocol/STTx.cpp
index b3de717da8..9f3c6738ae 100644
--- a/src/libxrpl/protocol/STTx.cpp
+++ b/src/libxrpl/protocol/STTx.cpp
@@ -765,7 +765,7 @@ isBatchRawTransactionOkay(STObject const& st, std::string& reason)
     {
         try
         {
-            TxType const tt = safeCast<TxType>(raw.getFieldU16(sfTransactionType));
+            auto const tt = safeCast<TxType>(raw.getFieldU16(sfTransactionType));
             if (tt == ttBATCH)
             {
                 reason = "Raw Transactions may not contain batch transactions.";
diff --git a/src/libxrpl/protocol/tokens.cpp b/src/libxrpl/protocol/tokens.cpp
index d04ceaa3a6..21984c67e7 100644
--- a/src/libxrpl/protocol/tokens.cpp
+++ b/src/libxrpl/protocol/tokens.cpp
@@ -23,6 +23,7 @@
 #include <cstdint>
 #include <cstring>
 #include <expected>
+#include <ranges>
 #include <span>
 #include <string>
 #include <string_view>
@@ -143,9 +144,10 @@ digest(void const* data, std::size_t size) noexcept
     return static_cast<Hasher::result_type>(h);
 }
 
-template <class Hasher, class T, std::size_t N, class = std::enable_if_t<sizeof(T) == 1>>
+template <class Hasher, class T, std::size_t N>
 static Hasher::result_type
 digest(std::array<T, N> const& v)
+    requires(sizeof(T) == 1)
 {
     return digest<Hasher>(v.data(), v.size());
 }
@@ -264,17 +266,17 @@ decodeBase58(std::string const& s)
 
     // Allocate enough space in big-endian base256 representation.
     // log(58) / log(256), rounded up.
-    std::vector<unsigned char> b256((remain * 733 / 1000) + 1);
+    std::vector<std::uint8_t> b256((remain * 733 / 1000) + 1);
     while (remain > 0)
     {
         auto carry = kAlphabetReverse[*psz];
         if (carry == -1)
             return {};
         // Apply "b256 = b256 * 58 + carry".
-        for (auto iter = b256.rbegin(); iter != b256.rend(); ++iter)
+        for (std::uint8_t& byte : std::views::reverse(b256))
         {
-            carry += 58 * *iter;
-            *iter = carry % 256;
+            carry += 58 * byte;
+            byte = carry % 256;
             carry /= 256;
         }
         XRPL_ASSERT(carry == 0, "xrpl::b58_ref::detail::decodeBase58 : zero carry");
@@ -282,7 +284,7 @@ decodeBase58(std::string const& s)
         --remain;
     }
     // Skip leading zeroes in b256.
-    auto iter = std::ranges::find_if(b256, [](unsigned char c) { return c != 0; });
+    auto iter = std::ranges::find_if(b256, [](std::uint8_t c) { return c != 0; });
     std::string result;
     result.reserve(zeroes + (b256.end() - iter));
     result.assign(zeroes, 0x00);
diff --git a/src/test/app/AMMMPT_test.cpp b/src/test/app/AMMMPT_test.cpp
index c68270591a..4877406ca1 100644
--- a/src/test/app/AMMMPT_test.cpp
+++ b/src/test/app/AMMMPT_test.cpp
@@ -3482,8 +3482,8 @@ private:
             // The vote is not added to the slots
             ammAlice.vote(carol_, 1'000);
             auto const info = ammAlice.ammRpcInfo()[jss::amm][jss::vote_slots];
-            for (auto i = 0; i < info.size(); ++i)
-                BEAST_EXPECT(info[i][jss::account] != carol_.human());
+            for (auto const& entry : info)
+                BEAST_EXPECT(entry[jss::account] != carol_.human());
             // But the slots are refreshed and the fee is changed
             BEAST_EXPECT(ammAlice.expectTradingFee(82));
         }
@@ -6270,7 +6270,7 @@ private:
                 auto const info = env.rpc(
                     "json",
                     "account_info",
-                    std::string("{\"account\": \"" + to_string(amm.ammAccount()) + "\"}"));
+                    std::string(R"({"account": ")" + to_string(amm.ammAccount()) + "\"}"));
                 try
                 {
                     BEAST_EXPECT(
diff --git a/src/test/app/AMM_test.cpp b/src/test/app/AMM_test.cpp
index d4b6ba5429..f19743026c 100644
--- a/src/test/app/AMM_test.cpp
+++ b/src/test/app/AMM_test.cpp
@@ -2463,8 +2463,8 @@ private:
             // The vote is not added to the slots
             ammAlice.vote(carol_, 1'000);
             auto const info = ammAlice.ammRpcInfo()[jss::amm][jss::vote_slots];
-            for (std::uint32_t i = 0; i < info.size(); ++i)
-                BEAST_EXPECT(info[i][jss::account] != carol_.human());
+            for (auto const& entry : info)
+                BEAST_EXPECT(entry[jss::account] != carol_.human());
             // But the slots are refreshed and the fee is changed
             BEAST_EXPECT(ammAlice.expectTradingFee(82));
         });
@@ -4436,7 +4436,7 @@ private:
             auto const info = env.rpc(
                 "json",
                 "account_info",
-                std::string("{\"account\": \"" + to_string(ammAlice.ammAccount()) + "\"}"));
+                std::string(R"({"account": ")" + to_string(ammAlice.ammAccount()) + "\"}"));
             auto const flags = info[jss::result][jss::account_data][jss::Flags].asUInt();
             BEAST_EXPECT(flags == (lsfDisableMaster | lsfDefaultRipple | lsfDepositAuth));
         });
@@ -5265,7 +5265,7 @@ private:
             auto const info = env.rpc(
                 "json",
                 "account_info",
-                std::string("{\"account\": \"" + to_string(amm.ammAccount()) + "\"}"));
+                std::string(R"({"account": ")" + to_string(amm.ammAccount()) + "\"}"));
             try
             {
                 BEAST_EXPECT(
diff --git a/src/test/app/LedgerReplay_test.cpp b/src/test/app/LedgerReplay_test.cpp
index bac1d8b61f..4cc83608d6 100644
--- a/src/test/app/LedgerReplay_test.cpp
+++ b/src/test/app/LedgerReplay_test.cpp
@@ -28,6 +28,7 @@
 
 #include <xrpl/basics/Slice.h>
 #include <xrpl/basics/base_uint.h>
+#include <xrpl/basics/random.h>
 #include <xrpl/beast/net/IPAddress.h>
 #include <xrpl/beast/net/IPEndpoint.h>
 #include <xrpl/beast/unit_test/suite.h>
@@ -452,7 +453,7 @@ struct TestPeerSet : public PeerSet
             dropRate = 100;
         }
 
-        if (((rand() % 100) + 1) <= dropRate)
+        if (randInt(1, 100) <= dropRate)
             return;
 
         switch (type)
diff --git a/src/test/app/NFToken_test.cpp b/src/test/app/NFToken_test.cpp
index f191e04a47..844bb4ee87 100644
--- a/src/test/app/NFToken_test.cpp
+++ b/src/test/app/NFToken_test.cpp
@@ -2404,7 +2404,7 @@ class NFTokenBaseUtil_test : public beast::unit_test::Suite
         // Do some touch testing to show that the taxon is recoverable no
         // matter what else changes around it in the nft ID.
         {
-            std::uint32_t const taxon = randInt<std::uint32_t>();
+            auto const taxon = randInt<std::uint32_t>();
             for (int i = 0; i < 10; ++i)
             {
                 // lambda to produce a useful message on error.
diff --git a/src/test/app/PayChan_test.cpp b/src/test/app/PayChan_test.cpp
index f1a9506e0c..5068472135 100644
--- a/src/test/app/PayChan_test.cpp
+++ b/src/test/app/PayChan_test.cpp
@@ -1323,10 +1323,10 @@ struct PayChan_test : public beast::unit_test::Suite
         auto sliceToHex = [](Slice const& slice) {
             std::string s;
             s.reserve(2 * slice.size());
-            for (int i = 0; i < slice.size(); ++i)
+            for (std::uint8_t const byte : slice)
             {
-                s += "0123456789ABCDEF"[((slice[i] & 0xf0) >> 4)];
-                s += "0123456789ABCDEF"[((slice[i] & 0x0f) >> 0)];
+                s += "0123456789ABCDEF"[((byte & 0xf0) >> 4)];
+                s += "0123456789ABCDEF"[((byte & 0x0f) >> 0)];
             }
             return s;
         };
diff --git a/src/test/app/PermissionedDomains_test.cpp b/src/test/app/PermissionedDomains_test.cpp
index 2cffc18682..784c2b4f56 100644
--- a/src/test/app/PermissionedDomains_test.cpp
+++ b/src/test/app/PermissionedDomains_test.cpp
@@ -289,8 +289,8 @@ class PermissionedDomains_test : public beast::unit_test::Suite
         for (auto const& c : alice)
             human2Acc.emplace(c.human(), c);
 
-        for (int i = 0; i < accNum; ++i)
-            env.fund(XRP(1000), alice[i]);
+        for (auto const& account : alice)
+            env.fund(XRP(1000), account);
 
         // Create new from existing account with a single credential.
         pdomain::Credentials const credentials1{{.issuer = alice[2], .credType = "credential1"}};
diff --git a/src/test/app/ValidatorList_test.cpp b/src/test/app/ValidatorList_test.cpp
index d71554f714..8077c21863 100644
--- a/src/test/app/ValidatorList_test.cpp
+++ b/src/test/app/ValidatorList_test.cpp
@@ -146,8 +146,8 @@ private:
 
         for (auto const& val : validators)
         {
-            data += "{\"validation_public_key\":\"" + strHex(val.masterPublic) +
-                "\",\"manifest\":\"" + val.manifest + "\"},";
+            data += R"({"validation_public_key":")" + strHex(val.masterPublic) +
+                R"(","manifest":")" + val.manifest + "\"},";
         }
 
         data.pop_back();
diff --git a/src/test/basics/Buffer_test.cpp b/src/test/basics/Buffer_test.cpp
deleted file mode 100644
index c748a3f9dd..0000000000
--- a/src/test/basics/Buffer_test.cpp
+++ /dev/null
@@ -1,268 +0,0 @@
-#include <xrpl/basics/Buffer.h>
-#include <xrpl/basics/Slice.h>
-#include <xrpl/beast/unit_test/suite.h>
-
-#include <cstddef>
-#include <cstdint>
-#include <cstring>
-#include <type_traits>
-#include <utility>
-
-namespace xrpl::test {
-
-struct Buffer_test : beast::unit_test::Suite
-{
-    static bool
-    sane(Buffer const& b)
-    {
-        if (b.empty())
-            return b.data() == nullptr;
-
-        return b.data() != nullptr;
-    }
-
-    void
-    run() override
-    {
-        std::uint8_t const data[] = {0xa8, 0xa1, 0x38, 0x45, 0x23, 0xec, 0xe4, 0x23,
-                                     0x71, 0x6d, 0x2a, 0x18, 0xb4, 0x70, 0xcb, 0xf5,
-                                     0xac, 0x2d, 0x89, 0x4d, 0x19, 0x9c, 0xf0, 0x2c,
-                                     0x15, 0xd1, 0xf9, 0x9b, 0x66, 0xd2, 0x30, 0xd3};
-
-        Buffer const b0;
-        BEAST_EXPECT(sane(b0));
-        BEAST_EXPECT(b0.empty());
-
-        Buffer b1{0};
-        BEAST_EXPECT(sane(b1));
-        BEAST_EXPECT(b1.empty());
-        std::memcpy(b1.alloc(16), data, 16);
-        BEAST_EXPECT(sane(b1));
-        BEAST_EXPECT(!b1.empty());
-        BEAST_EXPECT(b1.size() == 16);
-
-        Buffer b2{b1.size()};
-        BEAST_EXPECT(sane(b2));
-        BEAST_EXPECT(!b2.empty());
-        BEAST_EXPECT(b2.size() == b1.size());
-        std::memcpy(b2.data(), data + 16, 16);
-
-        Buffer b3{data, sizeof(data)};
-        BEAST_EXPECT(sane(b3));
-        BEAST_EXPECT(!b3.empty());
-        BEAST_EXPECT(b3.size() == sizeof(data));
-        BEAST_EXPECT(std::memcmp(b3.data(), data, b3.size()) == 0);
-
-        // Check equality and inequality comparisons
-        BEAST_EXPECT(b0 == b0);
-        BEAST_EXPECT(b0 != b1);
-        BEAST_EXPECT(b1 == b1);
-        BEAST_EXPECT(b1 != b2);
-        BEAST_EXPECT(b2 != b3);
-
-        // Check copy constructors and copy assignments:
-        {
-            testcase("Copy Construction / Assignment");
-
-            Buffer x{b0};
-            BEAST_EXPECT(x == b0);
-            BEAST_EXPECT(sane(x));
-            Buffer y{b1};
-            BEAST_EXPECT(y == b1);
-            BEAST_EXPECT(sane(y));
-            x = b2;
-            BEAST_EXPECT(x == b2);
-            BEAST_EXPECT(sane(x));
-            x = y;
-            BEAST_EXPECT(x == y);
-            BEAST_EXPECT(sane(x));
-            y = b3;
-            BEAST_EXPECT(y == b3);
-            BEAST_EXPECT(sane(y));
-            x = b0;
-            BEAST_EXPECT(x == b0);
-            BEAST_EXPECT(sane(x));
-#if defined(__clang__)
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wself-assign-overloaded"
-#endif
-
-            x = x;
-            BEAST_EXPECT(x == b0);
-            BEAST_EXPECT(sane(x));
-            y = y;
-            BEAST_EXPECT(y == b3);
-            BEAST_EXPECT(sane(y));
-
-#if defined(__clang__)
-#pragma clang diagnostic pop
-#endif
-        }
-
-        // Check move constructor & move assignments:
-        {
-            testcase("Move Construction / Assignment");
-
-            static_assert(std::is_nothrow_move_constructible_v<Buffer>);
-            static_assert(std::is_nothrow_move_assignable_v<Buffer>);
-
-            {  // Move-construct from empty buf
-                Buffer x;
-                Buffer const y{std::move(x)};
-                BEAST_EXPECT(sane(x));    // NOLINT(bugprone-use-after-move)
-                BEAST_EXPECT(x.empty());  // NOLINT(bugprone-use-after-move)
-                BEAST_EXPECT(sane(y));
-                BEAST_EXPECT(y.empty());
-                BEAST_EXPECT(x == y);  // NOLINT(bugprone-use-after-move)
-            }
-
-            {  // Move-construct from non-empty buf
-                Buffer x{b1};
-                Buffer const y{std::move(x)};
-                BEAST_EXPECT(sane(x));    // NOLINT(bugprone-use-after-move)
-                BEAST_EXPECT(x.empty());  // NOLINT(bugprone-use-after-move)
-                BEAST_EXPECT(sane(y));
-                BEAST_EXPECT(y == b1);
-            }
-
-            {  // Move assign empty buf to empty buf
-                Buffer x;
-                Buffer y;
-
-                x = std::move(y);
-                BEAST_EXPECT(sane(x));
-                BEAST_EXPECT(x.empty());
-                BEAST_EXPECT(sane(y));    // NOLINT(bugprone-use-after-move)
-                BEAST_EXPECT(y.empty());  // NOLINT(bugprone-use-after-move)
-            }
-
-            {  // Move assign non-empty buf to empty buf
-                Buffer x;
-                Buffer y{b1};
-
-                x = std::move(y);
-                BEAST_EXPECT(sane(x));
-                BEAST_EXPECT(x == b1);
-                BEAST_EXPECT(sane(y));    // NOLINT(bugprone-use-after-move)
-                BEAST_EXPECT(y.empty());  // NOLINT(bugprone-use-after-move)
-            }
-
-            {  // Move assign empty buf to non-empty buf
-                Buffer x{b1};
-                Buffer y;
-
-                x = std::move(y);
-                BEAST_EXPECT(sane(x));
-                BEAST_EXPECT(x.empty());
-                BEAST_EXPECT(sane(y));    // NOLINT(bugprone-use-after-move)
-                BEAST_EXPECT(y.empty());  // NOLINT(bugprone-use-after-move)
-            }
-
-            {  // Move assign non-empty buf to non-empty buf
-                Buffer x{b1};
-                Buffer y{b2};
-                Buffer z{b3};
-
-                x = std::move(y);
-                BEAST_EXPECT(sane(x));
-                BEAST_EXPECT(!x.empty());
-                BEAST_EXPECT(sane(y));    // NOLINT(bugprone-use-after-move)
-                BEAST_EXPECT(y.empty());  // NOLINT(bugprone-use-after-move)
-
-                x = std::move(z);
-                BEAST_EXPECT(sane(x));
-                BEAST_EXPECT(!x.empty());
-                BEAST_EXPECT(sane(z));    // NOLINT(bugprone-use-after-move)
-                BEAST_EXPECT(z.empty());  // NOLINT(bugprone-use-after-move)
-            }
-        }
-
-        {
-            testcase("Slice Conversion / Construction / Assignment");
-
-            Buffer w{static_cast<Slice>(b0)};
-            BEAST_EXPECT(sane(w));
-            BEAST_EXPECT(w == b0);
-
-            Buffer x{static_cast<Slice>(b1)};
-            BEAST_EXPECT(sane(x));
-            BEAST_EXPECT(x == b1);
-
-            Buffer y{static_cast<Slice>(b2)};
-            BEAST_EXPECT(sane(y));
-            BEAST_EXPECT(y == b2);
-
-            Buffer z{static_cast<Slice>(b3)};
-            BEAST_EXPECT(sane(z));
-            BEAST_EXPECT(z == b3);
-
-            // Assign empty slice to empty buffer
-            w = static_cast<Slice>(b0);
-            BEAST_EXPECT(sane(w));
-            BEAST_EXPECT(w == b0);
-
-            // Assign non-empty slice to empty buffer
-            w = static_cast<Slice>(b1);
-            BEAST_EXPECT(sane(w));
-            BEAST_EXPECT(w == b1);
-
-            // Assign non-empty slice to non-empty buffer
-            x = static_cast<Slice>(b2);
-            BEAST_EXPECT(sane(x));
-            BEAST_EXPECT(x == b2);
-
-            // Assign non-empty slice to non-empty buffer
-            y = static_cast<Slice>(z);
-            BEAST_EXPECT(sane(y));
-            BEAST_EXPECT(y == z);
-
-            // Assign empty slice to non-empty buffer:
-            z = static_cast<Slice>(b0);
-            BEAST_EXPECT(sane(z));
-            BEAST_EXPECT(z == b0);
-        }
-
-        {
-            testcase("Allocation, Deallocation and Clearing");
-
-            auto test = [this](Buffer const& b, std::size_t i) {
-                Buffer x{b};
-
-                // Try to allocate some number of bytes, possibly
-                // zero (which means clear) and sanity check
-                x(i);
-                BEAST_EXPECT(sane(x));
-                BEAST_EXPECT(x.size() == i);
-                BEAST_EXPECT((x.data() == nullptr) == (i == 0));
-
-                // Try to allocate some more data (always non-zero)
-                x(i + 1);
-                BEAST_EXPECT(sane(x));
-                BEAST_EXPECT(x.size() == i + 1);
-                BEAST_EXPECT(x.data() != nullptr);
-
-                // Try to clear:
-                x.clear();
-                BEAST_EXPECT(sane(x));
-                BEAST_EXPECT(x.empty());
-                BEAST_EXPECT(x.data() == nullptr);
-
-                // Try to clear again:
-                x.clear();
-                BEAST_EXPECT(sane(x));
-                BEAST_EXPECT(x.empty());
-                BEAST_EXPECT(x.data() == nullptr);
-            };
-
-            for (std::size_t i = 0; i < 16; ++i)
-            {
-                test(b0, i);
-                test(b1, i);
-            }
-        }
-    }
-};
-
-BEAST_DEFINE_TESTSUITE(Buffer, basics, xrpl);
-
-}  // namespace xrpl::test
diff --git a/src/test/basics/FileUtilities_test.cpp b/src/test/basics/FileUtilities_test.cpp
deleted file mode 100644
index 0e050b5168..0000000000
--- a/src/test/basics/FileUtilities_test.cpp
+++ /dev/null
@@ -1,64 +0,0 @@
-#include <test/unit_test/FileDirGuard.h>
-
-#include <xrpl/basics/ByteUtilities.h>
-#include <xrpl/basics/FileUtilities.h>
-#include <xrpl/beast/unit_test/suite.h>
-
-#include <boost/system/detail/errc.hpp>
-#include <boost/system/detail/error_code.hpp>
-
-namespace xrpl {
-
-class FileUtilities_test : public beast::unit_test::Suite
-{
-public:
-    void
-    testGetFileContents()
-    {
-        using namespace xrpl::detail;
-        using namespace boost::system;
-
-        static constexpr char const* kExpectedContents =
-            "This file is very short. That's all we need.";
-
-        FileDirGuard const file(
-            *this, "test_file", "test.txt", "This is temporary text that should get overwritten");
-
-        error_code ec;
-        auto const path = file.file();
-
-        writeFileContents(ec, path, kExpectedContents);
-        BEAST_EXPECT(!ec);
-
-        {
-            // Test with no max
-            auto const good = getFileContents(ec, path);
-            BEAST_EXPECT(!ec);
-            BEAST_EXPECT(good == kExpectedContents);
-        }
-
-        {
-            // Test with large max
-            auto const good = getFileContents(ec, path, kilobytes(1));
-            BEAST_EXPECT(!ec);
-            BEAST_EXPECT(good == kExpectedContents);
-        }
-
-        {
-            // Test with small max
-            auto const bad = getFileContents(ec, path, 16);
-            BEAST_EXPECT(ec && ec.value() == boost::system::errc::file_too_large);
-            BEAST_EXPECT(bad.empty());
-        }
-    }
-
-    void
-    run() override
-    {
-        testGetFileContents();
-    }
-};
-
-BEAST_DEFINE_TESTSUITE(FileUtilities, basics, xrpl);
-
-}  // namespace xrpl
diff --git a/src/test/basics/IOUAmount_test.cpp b/src/test/basics/IOUAmount_test.cpp
deleted file mode 100644
index b652d27625..0000000000
--- a/src/test/basics/IOUAmount_test.cpp
+++ /dev/null
@@ -1,276 +0,0 @@
-#include <xrpl/basics/Number.h>
-#include <xrpl/beast/unit_test/suite.h>
-#include <xrpl/beast/utility/Zero.h>
-#include <xrpl/protocol/IOUAmount.h>
-
-#include <cstdint>
-#include <limits>
-#include <sstream>
-
-namespace xrpl {
-
-class IOUAmount_test : public beast::unit_test::Suite
-{
-public:
-    void
-    testZero()
-    {
-        testcase("zero");
-
-        IOUAmount const z(0, 0);
-
-        BEAST_EXPECT(z.mantissa() == 0);
-        BEAST_EXPECT(z.exponent() == -100);
-        BEAST_EXPECT(!z);
-        BEAST_EXPECT(z.signum() == 0);
-        BEAST_EXPECT(z == beast::kZero);
-
-        BEAST_EXPECT((z + z) == z);
-        BEAST_EXPECT((z - z) == z);
-        BEAST_EXPECT(z == -z);
-
-        IOUAmount const zz(beast::kZero);
-        BEAST_EXPECT(z == zz);
-
-        // https://github.com/XRPLF/rippled/issues/5170
-        IOUAmount const zzz{};
-        BEAST_EXPECT(zzz == beast::kZero);
-        // BEAST_EXPECT(zzz == zz);
-    }
-
-    void
-    testSigNum()
-    {
-        testcase("signum");
-
-        IOUAmount const neg(-1, 0);
-        BEAST_EXPECT(neg.signum() < 0);
-
-        IOUAmount const zer(0, 0);
-        BEAST_EXPECT(zer.signum() == 0);
-
-        IOUAmount const pos(1, 0);
-        BEAST_EXPECT(pos.signum() > 0);
-    }
-
-    void
-    testBeastZero()
-    {
-        testcase("beast::Zero Comparisons");
-
-        using beast::kZero;
-
-        {
-            IOUAmount const z(kZero);
-            BEAST_EXPECT(z == kZero);
-            BEAST_EXPECT(z >= kZero);
-            BEAST_EXPECT(z <= kZero);
-            unexpected(z != kZero);
-            unexpected(z > kZero);
-            unexpected(z < kZero);
-        }
-
-        {
-            IOUAmount const neg(-2, 0);
-            BEAST_EXPECT(neg < kZero);
-            BEAST_EXPECT(neg <= kZero);
-            BEAST_EXPECT(neg != kZero);
-            unexpected(neg == kZero);
-        }
-
-        {
-            IOUAmount const pos(2, 0);
-            BEAST_EXPECT(pos > kZero);
-            BEAST_EXPECT(pos >= kZero);
-            BEAST_EXPECT(pos != kZero);
-            unexpected(pos == kZero);
-        }
-    }
-
-    void
-    testComparisons()
-    {
-        testcase("IOU Comparisons");
-
-        IOUAmount const n(-2, 0);
-        IOUAmount const z(0, 0);
-        IOUAmount const p(2, 0);
-
-        BEAST_EXPECT(z == z);
-        BEAST_EXPECT(z >= z);
-        BEAST_EXPECT(z <= z);
-        BEAST_EXPECT(z == -z);
-        // NOLINTBEGIN(misc-redundant-expression)
-        unexpected(z > z);
-        unexpected(z < z);
-        unexpected(z != z);
-        // NOLINTEND(misc-redundant-expression)
-        unexpected(z != -z);
-
-        BEAST_EXPECT(n < z);
-        BEAST_EXPECT(n <= z);
-        BEAST_EXPECT(n != z);
-        unexpected(n > z);
-        unexpected(n >= z);
-        unexpected(n == z);
-
-        BEAST_EXPECT(p > z);
-        BEAST_EXPECT(p >= z);
-        BEAST_EXPECT(p != z);
-        unexpected(p < z);
-        unexpected(p <= z);
-        unexpected(p == z);
-
-        BEAST_EXPECT(n < p);
-        BEAST_EXPECT(n <= p);
-        BEAST_EXPECT(n != p);
-        unexpected(n > p);
-        unexpected(n >= p);
-        unexpected(n == p);
-
-        BEAST_EXPECT(p > n);
-        BEAST_EXPECT(p >= n);
-        BEAST_EXPECT(p != n);
-        unexpected(p < n);
-        unexpected(p <= n);
-        unexpected(p == n);
-
-        BEAST_EXPECT(p > -p);
-        BEAST_EXPECT(p >= -p);
-        BEAST_EXPECT(p != -p);
-
-        BEAST_EXPECT(n < -n);
-        BEAST_EXPECT(n <= -n);
-        BEAST_EXPECT(n != -n);
-    }
-
-    void
-    testToString()
-    {
-        testcase("IOU strings");
-
-        auto test = [this](IOUAmount const& n, std::string const& expected) {
-            auto const result = to_string(n);
-            std::stringstream ss;
-            ss << "to_string(" << result << "). Expected: " << expected;
-            BEAST_EXPECTS(result == expected, ss.str());
-        };
-
-        for (auto const mantissaSize : MantissaRange::getAllScales())
-        {
-            NumberMantissaScaleGuard const mg(mantissaSize);
-
-            test(IOUAmount(-2, 0), "-2");
-            test(IOUAmount(0, 0), "0");
-            test(IOUAmount(2, 0), "2");
-            test(IOUAmount(25, -3), "0.025");
-            test(IOUAmount(-25, -3), "-0.025");
-            test(IOUAmount(25, 1), "250");
-            test(IOUAmount(-25, 1), "-250");
-            test(IOUAmount(2, 20), "2e20");
-            test(IOUAmount(-2, -20), "-2e-20");
-        }
-    }
-
-    void
-    testMulRatio()
-    {
-        testcase("mulRatio");
-
-        /* The range for the mantissa when normalized */
-        static constexpr std::int64_t kMinMantissa = 1000000000000000ull;
-        static constexpr std::int64_t kMaxMantissa = 9999999999999999ull;
-        // log(2,maxMantissa) ~ 53.15
-        /* The range for the exponent when normalized */
-        static constexpr int kMinExponent = -96;
-        static constexpr int kMaxExponent = 80;
-        constexpr auto kMaxUInt = std::numeric_limits<std::uint32_t>::max();
-
-        {
-            // multiply by a number that would overflow the mantissa, then
-            // divide by the same number, and check we didn't lose any value
-            IOUAmount const bigMan(kMaxMantissa, 0);
-            BEAST_EXPECT(bigMan == mulRatio(bigMan, kMaxUInt, kMaxUInt, true));
-            // rounding mode shouldn't matter as the result is exact
-            BEAST_EXPECT(bigMan == mulRatio(bigMan, kMaxUInt, kMaxUInt, false));
-        }
-        {
-            // Similar test as above, but for negative values
-            IOUAmount const bigMan(-kMaxMantissa, 0);
-            BEAST_EXPECT(bigMan == mulRatio(bigMan, kMaxUInt, kMaxUInt, true));
-            // rounding mode shouldn't matter as the result is exact
-            BEAST_EXPECT(bigMan == mulRatio(bigMan, kMaxUInt, kMaxUInt, false));
-        }
-
-        {
-            // small amounts
-            IOUAmount const tiny(kMinMantissa, kMinExponent);
-            // Round up should give the smallest allowable number
-            BEAST_EXPECT(tiny == mulRatio(tiny, 1, kMaxUInt, true));
-            BEAST_EXPECT(tiny == mulRatio(tiny, kMaxUInt - 1, kMaxUInt, true));
-            // rounding down should be zero
-            BEAST_EXPECT(beast::kZero == mulRatio(tiny, 1, kMaxUInt, false));
-            BEAST_EXPECT(beast::kZero == mulRatio(tiny, kMaxUInt - 1, kMaxUInt, false));
-
-            // tiny negative numbers
-            IOUAmount const tinyNeg(-kMinMantissa, kMinExponent);
-            // Round up should give zero
-            BEAST_EXPECT(beast::kZero == mulRatio(tinyNeg, 1, kMaxUInt, true));
-            BEAST_EXPECT(beast::kZero == mulRatio(tinyNeg, kMaxUInt - 1, kMaxUInt, true));
-            // rounding down should be tiny
-            BEAST_EXPECT(tinyNeg == mulRatio(tinyNeg, 1, kMaxUInt, false));
-            BEAST_EXPECT(tinyNeg == mulRatio(tinyNeg, kMaxUInt - 1, kMaxUInt, false));
-        }
-
-        {  // rounding
-            {
-                IOUAmount const one(1, 0);
-                auto const rup = mulRatio(one, kMaxUInt - 1, kMaxUInt, true);
-                auto const rdown = mulRatio(one, kMaxUInt - 1, kMaxUInt, false);
-                BEAST_EXPECT(rup.mantissa() - rdown.mantissa() == 1);
-            }
-            {
-                IOUAmount const big(kMaxMantissa, kMaxExponent);
-                auto const rup = mulRatio(big, kMaxUInt - 1, kMaxUInt, true);
-                auto const rdown = mulRatio(big, kMaxUInt - 1, kMaxUInt, false);
-                BEAST_EXPECT(rup.mantissa() - rdown.mantissa() == 1);
-            }
-
-            {
-                IOUAmount const negOne(-1, 0);
-                auto const rup = mulRatio(negOne, kMaxUInt - 1, kMaxUInt, true);
-                auto const rdown = mulRatio(negOne, kMaxUInt - 1, kMaxUInt, false);
-                BEAST_EXPECT(rup.mantissa() - rdown.mantissa() == 1);
-            }
-        }
-
-        {
-            // division by zero
-            IOUAmount one(1, 0);
-            except([&] { mulRatio(one, 1, 0, true); });
-        }
-
-        {
-            // overflow
-            IOUAmount big(kMaxMantissa, kMaxExponent);
-            except([&] { mulRatio(big, 2, 0, true); });
-        }
-    }  // namespace xrpl
-
-    //--------------------------------------------------------------------------
-
-    void
-    run() override
-    {
-        testZero();
-        testSigNum();
-        testBeastZero();
-        testComparisons();
-        testToString();
-        testMulRatio();
-    }
-};
-
-BEAST_DEFINE_TESTSUITE(IOUAmount, basics, xrpl);
-
-}  // namespace xrpl
diff --git a/src/test/basics/IntrusiveShared_test.cpp b/src/test/basics/IntrusiveShared_test.cpp
deleted file mode 100644
index 185b877f23..0000000000
--- a/src/test/basics/IntrusiveShared_test.cpp
+++ /dev/null
@@ -1,879 +0,0 @@
-
-#include <xrpl/basics/IntrusivePointer.h>    // IWYU pragma: keep
-#include <xrpl/basics/IntrusivePointer.ipp>  // IWYU pragma: keep
-#include <xrpl/basics/IntrusiveRefCounts.h>
-#include <xrpl/beast/unit_test/suite.h>
-
-#include <algorithm>
-#include <array>
-#include <atomic>
-#include <cassert>
-#include <chrono>  // IWYU pragma: keep
-#include <condition_variable>
-#include <cstddef>
-#include <cstdint>
-#include <functional>
-#include <latch>
-#include <mutex>
-#include <optional>
-#include <random>
-#include <string>
-#include <thread>
-#include <utility>
-#include <variant>
-#include <vector>
-
-namespace xrpl::tests {
-
-/**
-Experimentally, we discovered that using std::barrier performs extremely
-poorly (~1 hour vs ~1 minute to run the test suite) in certain macOS
-environments. To unblock our macOS CI pipeline, we replaced std::barrier with a
-custom mutex-based barrier (Barrier) that significantly improves performance
-without compromising correctness. For future reference, if we ever consider
-reintroducing std::barrier, the following configuration is known to exhibit the
-problem:
-
-    Model Name: Mac mini
-    Model Identifier: Mac14,3
-    Model Number: Z16K000R4LL/A
-    Chip: Apple M2
-    Total Number of Cores: 8 (4 performance and 4 efficiency)
-    Memory: 24 GB
-    System Firmware Version: 11881.41.5
-    OS Loader Version: 11881.1.1
-    Apple clang version 16.0.0 (clang-1600.0.26.3)
-    Target: arm64-apple-darwin24.0.0
-    Thread model: posix
-
- */
-struct Barrier
-{
-    std::mutex mtx;
-    std::condition_variable cv;
-    int count;
-    int const initial;
-
-    Barrier(int n) : count(n), initial(n)
-    {
-    }
-
-    void
-    arriveAndWait()
-    {
-        std::unique_lock lock(mtx);
-        if (--count == 0)
-        {
-            count = initial;
-            cv.notify_all();
-        }
-        else
-        {
-            cv.wait(lock, [&] { return count == initial; });
-        }
-    }
-};
-
-namespace {
-enum class TrackedState : std::uint8_t {
-    Uninitialized,
-    Alive,
-    PartiallyDeletedStarted,
-    PartiallyDeleted,
-    DeletedStarted,
-    Deleted
-};
-
-class TIBase : public IntrusiveRefCounts
-{
-public:
-    static constexpr std::size_t kMaxStates = 128;
-    static std::array<std::atomic<TrackedState>, kMaxStates> state;
-    static std::atomic<int> nextId;
-    static TrackedState
-    getState(int id)
-    {
-        assert(id < state.size());
-        return state[id].load(std::memory_order_acquire);
-    }
-    static void
-    resetStates(bool resetCallback)
-    {
-        for (int i = 0; i < kMaxStates; ++i)
-        {
-            state[i].store(TrackedState::Uninitialized, std::memory_order_release);
-        }
-        nextId.store(0, std::memory_order_release);
-        if (resetCallback)
-            TIBase::tracingCallback = [](TrackedState, std::optional<TrackedState>) {};
-    }
-
-    struct ResetStatesGuard
-    {
-        bool resetCallback{false};
-
-        ResetStatesGuard(bool resetCallback) : resetCallback{resetCallback}
-        {
-            TIBase::resetStates(resetCallback);
-        }
-        ~ResetStatesGuard()
-        {
-            TIBase::resetStates(resetCallback);
-        }
-    };
-
-    TIBase() : id{checkoutID()}
-    {
-        assert(state.size() > id);
-        state[id].store(TrackedState::Alive, std::memory_order_relaxed);
-    }
-    ~TIBase() override
-    {
-        using enum TrackedState;
-
-        assert(state.size() > id);
-        tracingCallback(state[id].load(std::memory_order_relaxed), DeletedStarted);
-
-        assert(state.size() > id);
-        // Use relaxed memory order to try to avoid atomic operations from
-        // adding additional memory synchronizations that may hide threading
-        // errors in the underlying shared pointer class.
-        state[id].store(DeletedStarted, std::memory_order_relaxed);
-
-        tracingCallback(DeletedStarted, Deleted);
-
-        assert(state.size() > id);
-        state[id].store(TrackedState::Deleted, std::memory_order_relaxed);
-
-        tracingCallback(TrackedState::Deleted, std::nullopt);
-    }
-
-    void
-    partialDestructor() const
-    {
-        using enum TrackedState;
-
-        assert(state.size() > id);
-        tracingCallback(state[id].load(std::memory_order_relaxed), PartiallyDeletedStarted);
-
-        assert(state.size() > id);
-        state[id].store(PartiallyDeletedStarted, std::memory_order_relaxed);
-
-        tracingCallback(PartiallyDeletedStarted, PartiallyDeleted);
-
-        assert(state.size() > id);
-        state[id].store(PartiallyDeleted, std::memory_order_relaxed);
-
-        tracingCallback(PartiallyDeleted, std::nullopt);
-    }
-
-    static std::function<void(TrackedState, std::optional<TrackedState>)> tracingCallback;
-
-    int id;
-
-private:
-    static int
-    checkoutID()
-    {
-        return nextId.fetch_add(1, std::memory_order_acq_rel);
-    }
-};
-
-std::array<std::atomic<TrackedState>, TIBase::kMaxStates> TIBase::state;
-std::atomic<int> TIBase::nextId{0};
-
-std::function<void(TrackedState, std::optional<TrackedState>)> TIBase::tracingCallback =
-    [](TrackedState, std::optional<TrackedState>) {};
-
-}  // namespace
-
-class IntrusiveShared_test : public beast::unit_test::Suite
-{
-public:
-    void
-    testBasics()
-    {
-        testcase("Basics");
-
-        {
-            TIBase::ResetStatesGuard const rsg{true};
-
-            TIBase const b;
-            BEAST_EXPECT(b.useCount() == 1);
-            b.addWeakRef();
-            BEAST_EXPECT(b.useCount() == 1);
-            auto s = b.releaseStrongRef();
-            BEAST_EXPECT(s == ReleaseStrongRefAction::PartialDestroy);
-            BEAST_EXPECT(b.useCount() == 0);
-            TIBase const* pb = &b;
-            partialDestructorFinished(&pb);
-            BEAST_EXPECT(!pb);
-            auto w = b.releaseWeakRef();
-            BEAST_EXPECT(w == ReleaseWeakRefAction::Destroy);
-        }
-
-        std::vector<SharedIntrusive<TIBase>> strong;
-        std::vector<WeakIntrusive<TIBase>> weak;
-        {
-            TIBase::ResetStatesGuard const rsg{true};
-
-            using enum TrackedState;
-            auto b = makeSharedIntrusive<TIBase>();
-            auto id = b->id;
-            BEAST_EXPECT(TIBase::getState(id) == Alive);
-            BEAST_EXPECT(b->useCount() == 1);
-            for (int i = 0; i < 10; ++i)
-            {
-                strong.push_back(b);
-            }
-            b.reset();
-            BEAST_EXPECT(TIBase::getState(id) == Alive);
-            strong.resize(strong.size() - 1);
-            BEAST_EXPECT(TIBase::getState(id) == Alive);
-            strong.clear();
-            BEAST_EXPECT(TIBase::getState(id) == Deleted);
-
-            b = makeSharedIntrusive<TIBase>();
-            id = b->id;
-            BEAST_EXPECT(TIBase::getState(id) == Alive);
-            BEAST_EXPECT(b->useCount() == 1);
-            for (int i = 0; i < 10; ++i)
-            {
-                weak.emplace_back(b);
-                BEAST_EXPECT(b->useCount() == 1);
-            }
-            BEAST_EXPECT(TIBase::getState(id) == Alive);
-            weak.resize(weak.size() - 1);
-            BEAST_EXPECT(TIBase::getState(id) == Alive);
-            b.reset();
-            BEAST_EXPECT(TIBase::getState(id) == PartiallyDeleted);
-            while (!weak.empty())
-            {
-                weak.resize(weak.size() - 1);
-                if (!weak.empty())
-                    BEAST_EXPECT(TIBase::getState(id) == PartiallyDeleted);
-            }
-            BEAST_EXPECT(TIBase::getState(id) == Deleted);
-        }
-        {
-            TIBase::ResetStatesGuard const rsg{true};
-
-            using enum TrackedState;
-            auto b = makeSharedIntrusive<TIBase>();
-            auto id = b->id;
-            BEAST_EXPECT(TIBase::getState(id) == Alive);
-            WeakIntrusive<TIBase> w{b};
-            BEAST_EXPECT(TIBase::getState(id) == Alive);
-            auto s = w.lock();
-            BEAST_EXPECT(s && s->useCount() == 2);
-            b.reset();
-            BEAST_EXPECT(TIBase::getState(id) == Alive);
-            BEAST_EXPECT(s && s->useCount() == 1);
-            s.reset();
-            BEAST_EXPECT(TIBase::getState(id) == PartiallyDeleted);
-            BEAST_EXPECT(w.expired());
-            s = w.lock();
-            // Cannot convert a weak pointer to a strong pointer if object is
-            // already partially deleted
-            BEAST_EXPECT(!s);
-            w.reset();
-            BEAST_EXPECT(TIBase::getState(id) == Deleted);
-        }
-        {
-            TIBase::ResetStatesGuard const rsg{true};
-
-            using enum TrackedState;
-            using swu = SharedWeakUnion<TIBase>;
-            swu b = makeSharedIntrusive<TIBase>();
-            BEAST_EXPECT(b.isStrong() && b.useCount() == 1);
-            auto id = b.get()->id;
-            BEAST_EXPECT(TIBase::getState(id) == Alive);
-            swu w = b;
-            BEAST_EXPECT(TIBase::getState(id) == Alive);
-            BEAST_EXPECT(w.isStrong() && b.useCount() == 2);
-            w.convertToWeak();
-            BEAST_EXPECT(w.isWeak() && b.useCount() == 1);
-            swu s = w;
-            BEAST_EXPECT(s.isWeak() && b.useCount() == 1);
-            s.convertToStrong();
-            BEAST_EXPECT(s.isStrong() && b.useCount() == 2);
-            b.reset();
-            BEAST_EXPECT(TIBase::getState(id) == Alive);
-            BEAST_EXPECT(s.useCount() == 1);
-            BEAST_EXPECT(!w.expired());
-            s.reset();
-            BEAST_EXPECT(TIBase::getState(id) == PartiallyDeleted);
-            BEAST_EXPECT(w.expired());
-            w.convertToStrong();
-            // Cannot convert a weak pointer to a strong pointer if object is
-            // already partially deleted
-            BEAST_EXPECT(w.isWeak());
-            w.reset();
-            BEAST_EXPECT(TIBase::getState(id) == Deleted);
-        }
-        {
-            // Testing SharedWeakUnion assignment operator
-
-            TIBase::ResetStatesGuard const rsg{true};
-
-            auto strong1 = makeSharedIntrusive<TIBase>();
-            auto strong2 = makeSharedIntrusive<TIBase>();
-
-            auto id1 = strong1->id;
-            auto id2 = strong2->id;
-
-            BEAST_EXPECT(id1 != id2);
-
-            SharedWeakUnion<TIBase> union1 = strong1;
-            SharedWeakUnion<TIBase> union2 = strong2;
-
-            BEAST_EXPECT(union1.isStrong());
-            BEAST_EXPECT(union2.isStrong());
-            BEAST_EXPECT(union1.get() == strong1.get());
-            BEAST_EXPECT(union2.get() == strong2.get());
-
-            // 1) Normal assignment: explicitly calls SharedWeakUnion assignment
-            union1 = union2;
-            BEAST_EXPECT(union1.isStrong());
-            BEAST_EXPECT(union2.isStrong());
-            BEAST_EXPECT(union1.get() == union2.get());
-            BEAST_EXPECT(TIBase::getState(id1) == TrackedState::Alive);
-            BEAST_EXPECT(TIBase::getState(id2) == TrackedState::Alive);
-
-            // 2) Test self-assignment
-            BEAST_EXPECT(union1.isStrong());
-            BEAST_EXPECT(TIBase::getState(id1) == TrackedState::Alive);
-            int const initialRefCount = strong1->useCount();
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wself-assign-overloaded"
-            union1 = union1;  // Self-assignment
-#pragma clang diagnostic pop
-            BEAST_EXPECT(union1.isStrong());
-            BEAST_EXPECT(TIBase::getState(id1) == TrackedState::Alive);
-            BEAST_EXPECT(strong1->useCount() == initialRefCount);
-
-            // 3) Test assignment from null union pointer
-            union1 = SharedWeakUnion<TIBase>();
-            BEAST_EXPECT(union1.get() == nullptr);
-
-            // 4) Test assignment to expired union pointer
-            strong2.reset();
-            union2.reset();
-            union1 = union2;
-            BEAST_EXPECT(union1.get() == nullptr);
-            BEAST_EXPECT(TIBase::getState(id2) == TrackedState::Deleted);
-        }
-    }
-
-    void
-    testPartialDelete()
-    {
-        testcase("Partial Delete");
-
-        // This test creates two threads. One with a strong pointer and one
-        // with a weak pointer. The strong pointer is reset while the weak
-        // pointer still holds a reference, triggering a partial delete.
-        // While the partial delete function runs (a sleep is inserted) the
-        // weak pointer is reset. The destructor should wait to run until
-        // after the partial delete function has completed running.
-
-        using enum TrackedState;
-
-        TIBase::ResetStatesGuard const rsg{true};
-
-        auto strong = makeSharedIntrusive<TIBase>();
-        WeakIntrusive<TIBase> weak{strong};
-        bool destructorRan = false;
-        bool partialDeleteRan = false;
-        std::latch partialDeleteStartedSyncPoint{2};
-        strong->tracingCallback = [&](TrackedState cur, std::optional<TrackedState> next) {
-            using enum TrackedState;
-            if (next == DeletedStarted)
-            {
-                // strong goes out of scope while weak is still in scope
-                // This checks that partialDelete has run to completion
-                // before the destructor is called. A sleep is inserted
-                // inside the partial delete to make sure the destructor is
-                // given an opportunity to run during partial delete.
-                BEAST_EXPECT(cur == PartiallyDeleted);
-            }
-            if (next == PartiallyDeletedStarted)
-            {
-                partialDeleteStartedSyncPoint.arrive_and_wait();
-                using namespace std::chrono_literals;
-                // Sleep and let the weak pointer go out of scope,
-                // potentially triggering a destructor while partial delete
-                // is running. The test is to make sure that doesn't happen.
-                std::this_thread::sleep_for(800ms);
-            }
-            if (next == PartiallyDeleted)
-            {
-                BEAST_EXPECT(!partialDeleteRan && !destructorRan);
-                partialDeleteRan = true;
-            }
-            if (next == Deleted)
-            {
-                BEAST_EXPECT(!destructorRan);
-                destructorRan = true;
-            }
-        };
-        std::thread t1{[&] {
-            partialDeleteStartedSyncPoint.arrive_and_wait();
-            weak.reset();  // Trigger a full delete as soon as the partial
-                           // delete starts
-        }};
-        std::thread t2{[&] {
-            strong.reset();  // Trigger a partial delete
-        }};
-        t1.join();
-        t2.join();
-
-        BEAST_EXPECT(destructorRan && partialDeleteRan);
-    }
-
-    void
-    testDestructor()
-    {
-        testcase("Destructor");
-
-        // This test creates two threads. One with a strong pointer and one
-        // with a weak pointer. The weak pointer is reset while the strong
-        // pointer still holds a reference. Then the strong pointer is
-        // reset. Only the destructor should run. The partial destructor
-        // should not be called. Since the weak reset runs to completion
-        // before the strong pointer is reset, threading doesn't add much to
-        // this test, but there is no harm in keeping it.
-
-        using enum TrackedState;
-
-        TIBase::ResetStatesGuard const rsg{true};
-
-        auto strong = makeSharedIntrusive<TIBase>();
-        WeakIntrusive<TIBase> weak{strong};
-        bool destructorRan = false;
-        bool partialDeleteRan = false;
-        std::latch weakResetSyncPoint{2};
-        strong->tracingCallback = [&](TrackedState cur, std::optional<TrackedState> next) {
-            using enum TrackedState;
-            if (next == PartiallyDeleted)
-            {
-                BEAST_EXPECT(!partialDeleteRan && !destructorRan);
-                partialDeleteRan = true;
-            }
-            if (next == Deleted)
-            {
-                BEAST_EXPECT(!destructorRan);
-                destructorRan = true;
-            }
-        };
-        std::thread t1{[&] {
-            weak.reset();
-            weakResetSyncPoint.arrive_and_wait();
-        }};
-        std::thread t2{[&] {
-            weakResetSyncPoint.arrive_and_wait();
-            strong.reset();  // Trigger a partial delete
-        }};
-        t1.join();
-        t2.join();
-
-        BEAST_EXPECT(destructorRan && !partialDeleteRan);
-    }
-
-    void
-    testMultithreadedClearMixedVariant()
-    {
-        testcase("Multithreaded Clear Mixed Variant");
-
-        // This test creates and destroys many strong and weak pointers in a
-        // loop. There is a random mix of strong and weak pointers stored in
-        // a vector (held as a variant). Both threads clear all the pointers
-        // and check that the invariants hold.
-
-        using enum TrackedState;
-        TIBase::ResetStatesGuard const rsg{true};
-
-        std::atomic<int> destructionState{0};
-        // returns destructorRan and partialDestructorRan (in that order)
-        auto getDestructorState = [&]() -> std::pair<bool, bool> {
-            int const s = destructionState.load(std::memory_order_relaxed);
-            return {(s & 1) != 0, (s & 2) != 0};
-        };
-        auto setDestructorRan = [&]() -> void {
-            destructionState.fetch_or(1, std::memory_order_acq_rel);
-        };
-        auto setPartialDeleteRan = [&]() -> void {
-            destructionState.fetch_or(2, std::memory_order_acq_rel);
-        };
-        auto tracingCallback = [&](TrackedState cur, std::optional<TrackedState> next) {
-            using enum TrackedState;
-            auto [destructorRan, partialDeleteRan] = getDestructorState();
-            if (next == PartiallyDeleted)
-            {
-                BEAST_EXPECT(!partialDeleteRan && !destructorRan);
-                setPartialDeleteRan();
-            }
-            if (next == Deleted)
-            {
-                BEAST_EXPECT(!destructorRan);
-                setDestructorRan();
-            }
-        };
-        auto createVecOfPointers = [&](auto const& toClone, std::default_random_engine& eng)
-            -> std::vector<std::variant<SharedIntrusive<TIBase>, WeakIntrusive<TIBase>>> {
-            std::vector<std::variant<SharedIntrusive<TIBase>, WeakIntrusive<TIBase>>> result;
-            std::uniform_int_distribution<> toCreateDist(4, 64);
-            std::uniform_int_distribution<> isStrongDist(0, 1);
-            auto numToCreate = toCreateDist(eng);
-            result.reserve(numToCreate);
-            for (int i = 0; i < numToCreate; ++i)
-            {
-                if (isStrongDist(eng))
-                {
-                    result.emplace_back(SharedIntrusive<TIBase>(toClone));
-                }
-                else
-                {
-                    result.emplace_back(WeakIntrusive<TIBase>(toClone));
-                }
-            }
-            return result;
-        };
-        static constexpr int kLoopIters = 2 * 1024;
-        static constexpr int kNumThreads = 16;
-        std::vector<SharedIntrusive<TIBase>> toClone;
-        Barrier loopStartSyncPoint{kNumThreads};
-        Barrier postCreateToCloneSyncPoint{kNumThreads};
-        Barrier postCreateVecOfPointersSyncPoint{kNumThreads};
-        auto engines = [&]() -> std::vector<std::default_random_engine> {
-            std::random_device rd;
-            std::vector<std::default_random_engine> result;
-            result.reserve(kNumThreads);
-            for (int i = 0; i < kNumThreads; ++i)
-                result.emplace_back(rd());
-            return result;
-        }();
-
-        // cloneAndDestroy clones the strong pointer into a vector of mixed
-        // strong and weak pointers and destroys them all at once.
-        // threadId==0 is special.
-        auto cloneAndDestroy = [&](int threadId) {
-            for (int i = 0; i < kLoopIters; ++i)
-            {
-                // ------ Sync Point ------
-                loopStartSyncPoint.arriveAndWait();
-
-                // only thread 0 should reset the state
-                std::optional<TIBase::ResetStatesGuard> rsg;
-                if (threadId == 0)
-                {
-                    // Thread 0 is the genesis thread. It creates the strong
-                    // pointers to be cloned by the other threads. This
-                    // thread will also check that the destructor ran and
-                    // clear the temporary variables.
-
-                    rsg.emplace(false);
-                    auto [destructorRan, partialDeleteRan] = getDestructorState();
-                    BEAST_EXPECT(!i || destructorRan);
-                    destructionState.store(0, std::memory_order_release);
-
-                    toClone.clear();
-                    toClone.resize(kNumThreads);
-                    auto strong = makeSharedIntrusive<TIBase>();
-                    strong->tracingCallback = tracingCallback;
-                    std::ranges::fill(toClone, strong);
-                }
-
-                // ------ Sync Point ------
-                postCreateToCloneSyncPoint.arriveAndWait();
-
-                auto v = createVecOfPointers(toClone[threadId], engines[threadId]);
-                toClone[threadId].reset();
-
-                // ------ Sync Point ------
-                postCreateVecOfPointersSyncPoint.arriveAndWait();
-
-                v.clear();
-            }
-        };
-        std::vector<std::thread> threads;
-        threads.reserve(kNumThreads);
-        for (int i = 0; i < kNumThreads; ++i)
-        {
-            threads.emplace_back(cloneAndDestroy, i);
-        }
-        for (int i = 0; i < kNumThreads; ++i)
-        {
-            threads[i].join();
-        }
-    }
-
-    void
-    testMultithreadedClearMixedUnion()
-    {
-        testcase("Multithreaded Clear Mixed Union");
-
-        // This test creates and destroys many SharedWeak pointers in a
-        // loop. All the pointers start as strong and a loop randomly
-        // convert them between strong and weak pointers. Both threads clear
-        // all the pointers and check that the invariants hold.
-        //
-        // Note: This test also differs from the test above in that the pointers
-        // randomly change from strong to weak and from weak to strong in a
-        // loop. This can't be done in the variant test above because variant is
-        // not thread safe while the SharedWeakUnion is thread safe.
-
-        using enum TrackedState;
-
-        TIBase::ResetStatesGuard const rsg{true};
-
-        std::atomic<int> destructionState{0};
-        // returns destructorRan and partialDestructorRan (in that order)
-        auto getDestructorState = [&]() -> std::pair<bool, bool> {
-            int const s = destructionState.load(std::memory_order_relaxed);
-            return {(s & 1) != 0, (s & 2) != 0};
-        };
-        auto setDestructorRan = [&]() -> void {
-            destructionState.fetch_or(1, std::memory_order_acq_rel);
-        };
-        auto setPartialDeleteRan = [&]() -> void {
-            destructionState.fetch_or(2, std::memory_order_acq_rel);
-        };
-        auto tracingCallback = [&](TrackedState cur, std::optional<TrackedState> next) {
-            using enum TrackedState;
-            auto [destructorRan, partialDeleteRan] = getDestructorState();
-            if (next == PartiallyDeleted)
-            {
-                BEAST_EXPECT(!partialDeleteRan && !destructorRan);
-                setPartialDeleteRan();
-            }
-            if (next == Deleted)
-            {
-                BEAST_EXPECT(!destructorRan);
-                setDestructorRan();
-            }
-        };
-        auto createVecOfPointers =
-            [&](auto const& toClone,
-                std::default_random_engine& eng) -> std::vector<SharedWeakUnion<TIBase>> {
-            std::vector<SharedWeakUnion<TIBase>> result;
-            std::uniform_int_distribution<> toCreateDist(4, 64);
-            auto numToCreate = toCreateDist(eng);
-            result.reserve(numToCreate);
-            for (int i = 0; i < numToCreate; ++i)
-                result.emplace_back(SharedIntrusive<TIBase>(toClone));
-            return result;
-        };
-        static constexpr int kLoopIters = 2 * 1024;
-        static constexpr int kFlipPointersLoopIters = 256;
-        static constexpr int kNumThreads = 16;
-        std::vector<SharedIntrusive<TIBase>> toClone;
-        Barrier loopStartSyncPoint{kNumThreads};
-        Barrier postCreateToCloneSyncPoint{kNumThreads};
-        Barrier postCreateVecOfPointersSyncPoint{kNumThreads};
-        Barrier postFlipPointersLoopSyncPoint{kNumThreads};
-        auto engines = [&]() -> std::vector<std::default_random_engine> {
-            std::random_device rd;
-            std::vector<std::default_random_engine> result;
-            result.reserve(kNumThreads);
-            for (int i = 0; i < kNumThreads; ++i)
-                result.emplace_back(rd());
-            return result;
-        }();
-
-        // cloneAndDestroy clones the strong pointer into a vector of
-        // mixed strong and weak pointers, runs a loop that randomly
-        // changes strong pointers to weak pointers,  and destroys them
-        // all at once.
-        auto cloneAndDestroy = [&](int threadId) {
-            for (int i = 0; i < kLoopIters; ++i)
-            {
-                // ------ Sync Point ------
-                loopStartSyncPoint.arriveAndWait();
-
-                // only thread 0 should reset the state
-                std::optional<TIBase::ResetStatesGuard> rsg;
-                if (threadId == 0)
-                {
-                    // threadId 0 is the genesis thread. It creates the
-                    // strong point to be cloned by the other threads. This
-                    // thread will also check that the destructor ran and
-                    // clear the temporary variables.
-                    rsg.emplace(false);
-                    auto [destructorRan, partialDeleteRan] = getDestructorState();
-                    BEAST_EXPECT(!i || destructorRan);
-                    destructionState.store(0, std::memory_order_release);
-
-                    toClone.clear();
-                    toClone.resize(kNumThreads);
-                    auto strong = makeSharedIntrusive<TIBase>();
-                    strong->tracingCallback = tracingCallback;
-                    std::ranges::fill(toClone, strong);
-                }
-
-                // ------ Sync Point ------
-                postCreateToCloneSyncPoint.arriveAndWait();
-
-                auto v = createVecOfPointers(toClone[threadId], engines[threadId]);
-                toClone[threadId].reset();
-
-                // ------ Sync Point ------
-                postCreateVecOfPointersSyncPoint.arriveAndWait();
-
-                std::uniform_int_distribution<> isStrongDist(0, 1);
-                for (int f = 0; f < kFlipPointersLoopIters; ++f)
-                {
-                    for (auto& p : v)
-                    {
-                        if (isStrongDist(engines[threadId]))
-                        {
-                            p.convertToStrong();
-                        }
-                        else
-                        {
-                            p.convertToWeak();
-                        }
-                    }
-                }
-
-                // ------ Sync Point ------
-                postFlipPointersLoopSyncPoint.arriveAndWait();
-
-                v.clear();
-            }
-        };
-        std::vector<std::thread> threads;
-        threads.reserve(kNumThreads);
-        for (int i = 0; i < kNumThreads; ++i)
-        {
-            threads.emplace_back(cloneAndDestroy, i);
-        }
-        for (int i = 0; i < kNumThreads; ++i)
-        {
-            threads[i].join();
-        }
-    }
-
-    void
-    testMultithreadedLockingWeak()
-    {
-        testcase("Multithreaded Locking Weak");
-
-        // This test creates a single shared atomic pointer that multiple thread
-        // create weak pointers from. The threads then lock the weak pointers.
-        // Both threads clear all the pointers and check that the invariants
-        // hold.
-
-        using enum TrackedState;
-
-        TIBase::ResetStatesGuard const rsg{true};
-
-        std::atomic<int> destructionState{0};
-        // returns destructorRan and partialDestructorRan (in that order)
-        auto getDestructorState = [&]() -> std::pair<bool, bool> {
-            int const s = destructionState.load(std::memory_order_relaxed);
-            return {(s & 1) != 0, (s & 2) != 0};
-        };
-        auto setDestructorRan = [&]() -> void {
-            destructionState.fetch_or(1, std::memory_order_acq_rel);
-        };
-        auto setPartialDeleteRan = [&]() -> void {
-            destructionState.fetch_or(2, std::memory_order_acq_rel);
-        };
-        auto tracingCallback = [&](TrackedState cur, std::optional<TrackedState> next) {
-            using enum TrackedState;
-            auto [destructorRan, partialDeleteRan] = getDestructorState();
-            if (next == PartiallyDeleted)
-            {
-                BEAST_EXPECT(!partialDeleteRan && !destructorRan);
-                setPartialDeleteRan();
-            }
-            if (next == Deleted)
-            {
-                BEAST_EXPECT(!destructorRan);
-                setDestructorRan();
-            }
-        };
-
-        static constexpr int kLoopIters = 2 * 1024;
-        static constexpr int kLockWeakLoopIters = 256;
-        static constexpr int kNumThreads = 16;
-        std::vector<SharedIntrusive<TIBase>> toLock;
-        Barrier loopStartSyncPoint{kNumThreads};
-        Barrier postCreateToLockSyncPoint{kNumThreads};
-        Barrier postLockWeakLoopSyncPoint{kNumThreads};
-
-        // lockAndDestroy creates weak pointers from the strong pointer
-        // and runs a loop that locks the weak pointer. At the end of the loop
-        // all the pointers are destroyed all at once.
-        auto lockAndDestroy = [&](int threadId) {
-            for (int i = 0; i < kLoopIters; ++i)
-            {
-                // ------ Sync Point ------
-                loopStartSyncPoint.arriveAndWait();
-
-                // only thread 0 should reset the state
-                std::optional<TIBase::ResetStatesGuard> rsg;
-                if (threadId == 0)
-                {
-                    // threadId 0 is the genesis thread. It creates the
-                    // strong point to be locked by the other threads. This
-                    // thread will also check that the destructor ran and
-                    // clear the temporary variables.
-                    rsg.emplace(false);
-                    auto [destructorRan, partialDeleteRan] = getDestructorState();
-                    BEAST_EXPECT(!i || destructorRan);
-                    destructionState.store(0, std::memory_order_release);
-
-                    toLock.clear();
-                    toLock.resize(kNumThreads);
-                    auto strong = makeSharedIntrusive<TIBase>();
-                    strong->tracingCallback = tracingCallback;
-                    std::ranges::fill(toLock, strong);
-                }
-
-                // ------ Sync Point ------
-                postCreateToLockSyncPoint.arriveAndWait();
-
-                // Multiple threads all create a weak pointer from the same
-                // strong pointer
-                WeakIntrusive const weak{toLock[threadId]};
-                for (int wi = 0; wi < kLockWeakLoopIters; ++wi)
-                {
-                    BEAST_EXPECT(!weak.expired());
-                    auto strong = weak.lock();
-                    BEAST_EXPECT(strong);
-                }
-
-                // ------ Sync Point ------
-                postLockWeakLoopSyncPoint.arriveAndWait();
-
-                toLock[threadId].reset();
-            }
-        };
-        std::vector<std::thread> threads;
-        threads.reserve(kNumThreads);
-        for (int i = 0; i < kNumThreads; ++i)
-        {
-            threads.emplace_back(lockAndDestroy, i);
-        }
-        for (int i = 0; i < kNumThreads; ++i)
-        {
-            threads[i].join();
-        }
-    }
-
-    void
-    run() override
-    {
-        testBasics();
-        testPartialDelete();
-        testDestructor();
-        testMultithreadedClearMixedVariant();
-        testMultithreadedClearMixedUnion();
-        testMultithreadedLockingWeak();
-    }
-};  // namespace tests
-
-BEAST_DEFINE_TESTSUITE(IntrusiveShared, basics, xrpl);
-}  // namespace xrpl::tests
diff --git a/src/test/basics/KeyCache_test.cpp b/src/test/basics/KeyCache_test.cpp
deleted file mode 100644
index e83ae4c277..0000000000
--- a/src/test/basics/KeyCache_test.cpp
+++ /dev/null
@@ -1,82 +0,0 @@
-#include <test/unit_test/SuiteJournal.h>
-
-#include <xrpl/basics/TaggedCache.h>
-#include <xrpl/basics/TaggedCache.ipp>  // IWYU pragma: keep
-#include <xrpl/basics/chrono.h>
-#include <xrpl/beast/unit_test/suite.h>
-#include <xrpl/protocol/Protocol.h>
-
-#include <string>
-
-namespace xrpl {
-
-class KeyCache_test : public beast::unit_test::Suite
-{
-public:
-    void
-    run() override
-    {
-        using namespace std::chrono_literals;
-        TestStopwatch clock;
-        clock.set(0);
-
-        using Key = std::string;
-        using Cache = TaggedCache<Key, int, true>;
-
-        test::SuiteJournal j("KeyCacheTest", *this);
-
-        // Insert an item, retrieve it, and age it so it gets purged.
-        {
-            Cache c("test", LedgerIndex(1), 2s, clock, j);
-
-            BEAST_EXPECT(c.size() == 0);
-            BEAST_EXPECT(c.insert("one"));
-            BEAST_EXPECT(!c.insert("one"));
-            BEAST_EXPECT(c.size() == 1);
-            BEAST_EXPECT(c.touchIfExists("one"));
-            ++clock;
-            c.sweep();
-            BEAST_EXPECT(c.size() == 1);
-            ++clock;
-            c.sweep();
-            BEAST_EXPECT(c.size() == 0);
-            BEAST_EXPECT(!c.touchIfExists("one"));
-        }
-
-        // Insert two items, have one expire
-        {
-            Cache c("test", LedgerIndex(2), 2s, clock, j);
-
-            BEAST_EXPECT(c.insert("one"));
-            BEAST_EXPECT(c.size() == 1);
-            BEAST_EXPECT(c.insert("two"));
-            BEAST_EXPECT(c.size() == 2);
-            ++clock;
-            c.sweep();
-            BEAST_EXPECT(c.size() == 2);
-            BEAST_EXPECT(c.touchIfExists("two"));
-            ++clock;
-            c.sweep();
-            BEAST_EXPECT(c.size() == 1);
-        }
-
-        // Insert three items (1 over limit), sweep
-        {
-            Cache c("test", LedgerIndex(2), 3s, clock, j);
-
-            BEAST_EXPECT(c.insert("one"));
-            ++clock;
-            BEAST_EXPECT(c.insert("two"));
-            ++clock;
-            BEAST_EXPECT(c.insert("three"));
-            ++clock;
-            BEAST_EXPECT(c.size() == 3);
-            c.sweep();
-            BEAST_EXPECT(c.size() < 3);
-        }
-    }
-};
-
-BEAST_DEFINE_TESTSUITE(KeyCache, basics, xrpl);
-
-}  // namespace xrpl
diff --git a/src/test/basics/StringUtilities_test.cpp b/src/test/basics/StringUtilities_test.cpp
deleted file mode 100644
index e12bc53857..0000000000
--- a/src/test/basics/StringUtilities_test.cpp
+++ /dev/null
@@ -1,309 +0,0 @@
-#include <xrpl/basics/Slice.h>
-#include <xrpl/basics/StringUtilities.h>
-#include <xrpl/basics/ToString.h>
-#include <xrpl/beast/unit_test/suite.h>
-
-#include <string>
-
-namespace xrpl {
-
-class StringUtilities_test : public beast::unit_test::Suite
-{
-public:
-    void
-    testUnHexSuccess(std::string const& strIn, std::string const& strExpected)
-    {
-        auto rv = strUnHex(strIn);
-        BEAST_EXPECT(rv);
-
-        // NOLINTNEXTLINE(bugprone-unchecked-optional-access)
-        BEAST_EXPECT(makeSlice(*rv) == makeSlice(strExpected));
-    }
-
-    void
-    testUnHexFailure(std::string const& strIn)
-    {
-        auto rv = strUnHex(strIn);
-        BEAST_EXPECT(!rv);
-    }
-
-    void
-    testUnHex()
-    {
-        testcase("strUnHex");
-
-        testUnHexSuccess("526970706c6544", "RippleD");
-        testUnHexSuccess("A", "\n");
-        testUnHexSuccess("0A", "\n");
-        testUnHexSuccess("D0A", "\r\n");
-        testUnHexSuccess("0D0A", "\r\n");
-        testUnHexSuccess("200D0A", " \r\n");
-        testUnHexSuccess("282A2B2C2D2E2F29", "(*+,-./)");
-
-        // Check for things which contain some or only invalid characters
-        testUnHexFailure("123X");
-        testUnHexFailure("V");
-        testUnHexFailure("XRP");
-    }
-
-    void
-    testParseUrl()
-    {
-        testcase("parseUrl");
-
-        // Expected passes.
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "scheme://"));
-            BEAST_EXPECT(pUrl.scheme == "scheme");
-            BEAST_EXPECT(pUrl.username.empty());
-            BEAST_EXPECT(pUrl.password.empty());
-            BEAST_EXPECT(pUrl.domain.empty());
-            BEAST_EXPECT(!pUrl.port);
-            // RFC 3986:
-            // > In general, a URI that uses the generic syntax for authority
-            //   with an empty path should be normalized to a path of "/".
-            // Do we want to normalize paths?
-            BEAST_EXPECT(pUrl.path.empty());
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "scheme:///"));
-            BEAST_EXPECT(pUrl.scheme == "scheme");
-            BEAST_EXPECT(pUrl.username.empty());
-            BEAST_EXPECT(pUrl.password.empty());
-            BEAST_EXPECT(pUrl.domain.empty());
-            BEAST_EXPECT(!pUrl.port);
-            BEAST_EXPECT(pUrl.path == "/");
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "lower://domain"));
-            BEAST_EXPECT(pUrl.scheme == "lower");
-            BEAST_EXPECT(pUrl.username.empty());
-            BEAST_EXPECT(pUrl.password.empty());
-            BEAST_EXPECT(pUrl.domain == "domain");
-            BEAST_EXPECT(!pUrl.port);
-            BEAST_EXPECT(pUrl.path.empty());
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "UPPER://domain:234/"));
-            BEAST_EXPECT(pUrl.scheme == "upper");
-            BEAST_EXPECT(pUrl.username.empty());
-            BEAST_EXPECT(pUrl.password.empty());
-            BEAST_EXPECT(pUrl.domain == "domain");
-            BEAST_EXPECT(*pUrl.port == 234);  // NOLINT(bugprone-unchecked-optional-access)
-            BEAST_EXPECT(pUrl.path == "/");
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "Mixed://domain/path"));
-            BEAST_EXPECT(pUrl.scheme == "mixed");
-            BEAST_EXPECT(pUrl.username.empty());
-            BEAST_EXPECT(pUrl.password.empty());
-            BEAST_EXPECT(pUrl.domain == "domain");
-            BEAST_EXPECT(!pUrl.port);
-            BEAST_EXPECT(pUrl.path == "/path");
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "scheme://[::1]:123/path"));
-            BEAST_EXPECT(pUrl.scheme == "scheme");
-            BEAST_EXPECT(pUrl.username.empty());
-            BEAST_EXPECT(pUrl.password.empty());
-            BEAST_EXPECT(pUrl.domain == "::1");
-            BEAST_EXPECT(*pUrl.port == 123);  // NOLINT(bugprone-unchecked-optional-access)
-            BEAST_EXPECT(pUrl.path == "/path");
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "scheme://user:pass@domain:123/abc:321"));
-            BEAST_EXPECT(pUrl.scheme == "scheme");
-            BEAST_EXPECT(pUrl.username == "user");
-            BEAST_EXPECT(pUrl.password == "pass");
-            BEAST_EXPECT(pUrl.domain == "domain");
-            BEAST_EXPECT(*pUrl.port == 123);  // NOLINT(bugprone-unchecked-optional-access)
-            BEAST_EXPECT(pUrl.path == "/abc:321");
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "scheme://user@domain:123/abc:321"));
-            BEAST_EXPECT(pUrl.scheme == "scheme");
-            BEAST_EXPECT(pUrl.username == "user");
-            BEAST_EXPECT(pUrl.password.empty());
-            BEAST_EXPECT(pUrl.domain == "domain");
-            BEAST_EXPECT(*pUrl.port == 123);  // NOLINT(bugprone-unchecked-optional-access)
-            BEAST_EXPECT(pUrl.path == "/abc:321");
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "scheme://:pass@domain:123/abc:321"));
-            BEAST_EXPECT(pUrl.scheme == "scheme");
-            BEAST_EXPECT(pUrl.username.empty());
-            BEAST_EXPECT(pUrl.password == "pass");
-            BEAST_EXPECT(pUrl.domain == "domain");
-            BEAST_EXPECT(*pUrl.port == 123);  // NOLINT(bugprone-unchecked-optional-access)
-            BEAST_EXPECT(pUrl.path == "/abc:321");
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "scheme://domain:123/abc:321"));
-            BEAST_EXPECT(pUrl.scheme == "scheme");
-            BEAST_EXPECT(pUrl.username.empty());
-            BEAST_EXPECT(pUrl.password.empty());
-            BEAST_EXPECT(pUrl.domain == "domain");
-            BEAST_EXPECT(*pUrl.port == 123);  // NOLINT(bugprone-unchecked-optional-access)
-            BEAST_EXPECT(pUrl.path == "/abc:321");
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "scheme://user:pass@domain/abc:321"));
-            BEAST_EXPECT(pUrl.scheme == "scheme");
-            BEAST_EXPECT(pUrl.username == "user");
-            BEAST_EXPECT(pUrl.password == "pass");
-            BEAST_EXPECT(pUrl.domain == "domain");
-            BEAST_EXPECT(!pUrl.port);
-            BEAST_EXPECT(pUrl.path == "/abc:321");
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "scheme://user@domain/abc:321"));
-            BEAST_EXPECT(pUrl.scheme == "scheme");
-            BEAST_EXPECT(pUrl.username == "user");
-            BEAST_EXPECT(pUrl.password.empty());
-            BEAST_EXPECT(pUrl.domain == "domain");
-            BEAST_EXPECT(!pUrl.port);
-            BEAST_EXPECT(pUrl.path == "/abc:321");
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "scheme://:pass@domain/abc:321"));
-            BEAST_EXPECT(pUrl.scheme == "scheme");
-            BEAST_EXPECT(pUrl.username.empty());
-            BEAST_EXPECT(pUrl.password == "pass");
-            BEAST_EXPECT(pUrl.domain == "domain");
-            BEAST_EXPECT(!pUrl.port);
-            BEAST_EXPECT(pUrl.path == "/abc:321");
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "scheme://domain/abc:321"));
-            BEAST_EXPECT(pUrl.scheme == "scheme");
-            BEAST_EXPECT(pUrl.username.empty());
-            BEAST_EXPECT(pUrl.password.empty());
-            BEAST_EXPECT(pUrl.domain == "domain");
-            BEAST_EXPECT(!pUrl.port);
-            BEAST_EXPECT(pUrl.path == "/abc:321");
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "scheme:///path/to/file"));
-            BEAST_EXPECT(pUrl.scheme == "scheme");
-            BEAST_EXPECT(pUrl.username.empty());
-            BEAST_EXPECT(pUrl.password.empty());
-            BEAST_EXPECT(pUrl.domain.empty());
-            BEAST_EXPECT(!pUrl.port);
-            BEAST_EXPECT(pUrl.path == "/path/to/file");
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "scheme://user:pass@domain/path/with/an@sign"));
-            BEAST_EXPECT(pUrl.scheme == "scheme");
-            BEAST_EXPECT(pUrl.username == "user");
-            BEAST_EXPECT(pUrl.password == "pass");
-            BEAST_EXPECT(pUrl.domain == "domain");
-            BEAST_EXPECT(!pUrl.port);
-            BEAST_EXPECT(pUrl.path == "/path/with/an@sign");
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "scheme://domain/path/with/an@sign"));
-            BEAST_EXPECT(pUrl.scheme == "scheme");
-            BEAST_EXPECT(pUrl.username.empty());
-            BEAST_EXPECT(pUrl.password.empty());
-            BEAST_EXPECT(pUrl.domain == "domain");
-            BEAST_EXPECT(!pUrl.port);
-            BEAST_EXPECT(pUrl.path == "/path/with/an@sign");
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "scheme://:999/"));
-            BEAST_EXPECT(pUrl.scheme == "scheme");
-            BEAST_EXPECT(pUrl.username.empty());
-            BEAST_EXPECT(pUrl.password.empty());
-            BEAST_EXPECT(pUrl.domain == ":999");
-            BEAST_EXPECT(!pUrl.port);
-            BEAST_EXPECT(pUrl.path == "/");
-        }
-
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(parseUrl(pUrl, "http://::1:1234/validators"));
-            BEAST_EXPECT(pUrl.scheme == "http");
-            BEAST_EXPECT(pUrl.username.empty());
-            BEAST_EXPECT(pUrl.password.empty());
-            BEAST_EXPECT(pUrl.domain == "::0.1.18.52");
-            BEAST_EXPECT(!pUrl.port);
-            BEAST_EXPECT(pUrl.path == "/validators");
-        }
-
-        // Expected fails.
-        {
-            ParsedUrl pUrl;
-            BEAST_EXPECT(!parseUrl(pUrl, ""));
-            BEAST_EXPECT(!parseUrl(pUrl, "nonsense"));
-            BEAST_EXPECT(!parseUrl(pUrl, "://"));
-            BEAST_EXPECT(!parseUrl(pUrl, ":///"));
-            BEAST_EXPECT(!parseUrl(pUrl, "scheme://user:pass@domain:65536/abc:321"));
-            BEAST_EXPECT(!parseUrl(pUrl, "UPPER://domain:23498765/"));
-            BEAST_EXPECT(!parseUrl(pUrl, "UPPER://domain:0/"));
-            BEAST_EXPECT(!parseUrl(pUrl, "UPPER://domain:+7/"));
-            BEAST_EXPECT(!parseUrl(pUrl, "UPPER://domain:-7234/"));
-            BEAST_EXPECT(!parseUrl(pUrl, "UPPER://domain:@#$56!/"));
-        }
-
-        {
-            std::string const strUrl("s://" + std::string(8192, ':'));
-            ParsedUrl pUrl;
-            BEAST_EXPECT(!parseUrl(pUrl, strUrl));
-        }
-    }
-
-    void
-    testToString()
-    {
-        testcase("toString");
-        auto result = to_string("hello");
-        BEAST_EXPECT(result == "hello");
-    }
-
-    void
-    run() override
-    {
-        testParseUrl();
-        testUnHex();
-        testToString();
-    }
-};
-
-BEAST_DEFINE_TESTSUITE(StringUtilities, basics, xrpl);
-
-}  // namespace xrpl
diff --git a/src/test/basics/TaggedCache_test.cpp b/src/test/basics/TaggedCache_test.cpp
deleted file mode 100644
index 26564a4de8..0000000000
--- a/src/test/basics/TaggedCache_test.cpp
+++ /dev/null
@@ -1,251 +0,0 @@
-#include <test/unit_test/SuiteJournal.h>
-
-#include <xrpl/basics/IntrusivePointer.h>
-#include <xrpl/basics/IntrusiveRefCounts.h>
-#include <xrpl/basics/TaggedCache.h>
-#include <xrpl/basics/TaggedCache.ipp>  // IWYU pragma: keep
-#include <xrpl/basics/chrono.h>
-#include <xrpl/beast/unit_test/suite.h>
-#include <xrpl/beast/utility/Journal.h>
-#include <xrpl/protocol/Protocol.h>
-
-#include <memory>
-#include <utility>
-
-namespace xrpl {
-
-/*
-I guess you can put some items in, make sure they're still there. Let some
-time pass, make sure they're gone. Keep a strong pointer to one of them, make
-sure you can still find it even after time passes. Create two objects with
-the same key, canonicalize them both and make sure you get the same object.
-Put an object in but keep a strong pointer to it, advance the clock a lot,
-then canonicalize a new object with the same key, make sure you get the
-original object.
-*/
-
-class TaggedCache_test : public beast::unit_test::Suite
-{
-public:
-    void
-    run() override
-    {
-        using namespace std::chrono_literals;
-        using beast::Severity;
-        test::SuiteJournal journal("TaggedCache_test", *this);
-
-        TestStopwatch clock;
-        clock.set(0);
-
-        using Key = LedgerIndex;
-        using Value = std::string;
-        using Cache = TaggedCache<Key, Value>;
-
-        Cache c("test", 1, 1s, clock, journal);
-
-        // Insert an item, retrieve it, and age it so it gets purged.
-        {
-            BEAST_EXPECT(c.getCacheSize() == 0);
-            BEAST_EXPECT(c.getTrackSize() == 0);
-            BEAST_EXPECT(!c.insert(1, "one"));
-            BEAST_EXPECT(c.getCacheSize() == 1);
-            BEAST_EXPECT(c.getTrackSize() == 1);
-
-            {
-                std::string s;
-                BEAST_EXPECT(c.retrieve(1, s));
-                BEAST_EXPECT(s == "one");
-            }
-
-            ++clock;
-            c.sweep();
-            BEAST_EXPECT(c.getCacheSize() == 0);
-            BEAST_EXPECT(c.getTrackSize() == 0);
-        }
-
-        // Insert an item, maintain a strong pointer, age it, and
-        // verify that the entry still exists.
-        {
-            BEAST_EXPECT(!c.insert(2, "two"));
-            BEAST_EXPECT(c.getCacheSize() == 1);
-            BEAST_EXPECT(c.getTrackSize() == 1);
-
-            {
-                auto p = c.fetch(2);
-                BEAST_EXPECT(p != nullptr);
-                ++clock;
-                c.sweep();
-                BEAST_EXPECT(c.getCacheSize() == 0);
-                BEAST_EXPECT(c.getTrackSize() == 1);
-            }
-
-            // Make sure its gone now that our reference is gone
-            ++clock;
-            c.sweep();
-            BEAST_EXPECT(c.getCacheSize() == 0);
-            BEAST_EXPECT(c.getTrackSize() == 0);
-        }
-
-        // Insert the same key/value pair and make sure we get the same result
-        {
-            BEAST_EXPECT(!c.insert(3, "three"));
-
-            {
-                auto const p1 = c.fetch(3);
-                auto p2 = std::make_shared<Value>("three");
-                c.canonicalizeReplaceClient(3, p2);
-                BEAST_EXPECT(p1.get() == p2.get());
-            }
-            ++clock;
-            c.sweep();
-            BEAST_EXPECT(c.getCacheSize() == 0);
-            BEAST_EXPECT(c.getTrackSize() == 0);
-        }
-
-        // Put an object in but keep a strong pointer to it, advance the clock a
-        // lot, then canonicalize a new object with the same key, make sure you
-        // get the original object.
-        {
-            // Put an object in
-            BEAST_EXPECT(!c.insert(4, "four"));
-            BEAST_EXPECT(c.getCacheSize() == 1);
-            BEAST_EXPECT(c.getTrackSize() == 1);
-
-            {
-                // Keep a strong pointer to it
-                auto const p1 = c.fetch(4);
-                BEAST_EXPECT(p1 != nullptr);
-                BEAST_EXPECT(c.getCacheSize() == 1);
-                BEAST_EXPECT(c.getTrackSize() == 1);
-                // Advance the clock a lot
-                ++clock;
-                c.sweep();
-                BEAST_EXPECT(c.getCacheSize() == 0);
-                BEAST_EXPECT(c.getTrackSize() == 1);
-                // Canonicalize a new object with the same key
-                auto p2 = std::make_shared<std::string>("four");
-                BEAST_EXPECT(c.canonicalizeReplaceClient(4, p2));
-                BEAST_EXPECT(c.getCacheSize() == 1);
-                BEAST_EXPECT(c.getTrackSize() == 1);
-                // Make sure we get the original object
-                BEAST_EXPECT(p1.get() == p2.get());
-            }
-
-            ++clock;
-            c.sweep();
-            BEAST_EXPECT(c.getCacheSize() == 0);
-            BEAST_EXPECT(c.getTrackSize() == 0);
-        }
-        {
-            BEAST_EXPECT(!c.insert(5, "five"));
-            BEAST_EXPECT(c.getCacheSize() == 1);
-            BEAST_EXPECT(c.size() == 1);
-
-            {
-                auto const p1 = c.fetch(5);
-                BEAST_EXPECT(p1 != nullptr);
-                BEAST_EXPECT(c.getCacheSize() == 1);
-                BEAST_EXPECT(c.size() == 1);
-
-                // Advance the clock a lot
-                ++clock;
-                c.sweep();
-                BEAST_EXPECT(c.getCacheSize() == 0);
-                BEAST_EXPECT(c.size() == 1);
-
-                auto p2 = std::make_shared<std::string>("five_2");
-                BEAST_EXPECT(c.canonicalizeReplaceCache(5, p2));
-                BEAST_EXPECT(c.getCacheSize() == 1);
-                BEAST_EXPECT(c.size() == 1);
-                // Make sure the caller's original pointer is unchanged
-                BEAST_EXPECT(p1.get() != p2.get());
-                BEAST_EXPECT(*p2 == "five_2");
-
-                auto const p3 = c.fetch(5);
-                BEAST_EXPECT(p3 != nullptr);
-                BEAST_EXPECT(p3.get() == p2.get());
-                BEAST_EXPECT(p3.get() != p1.get());
-            }
-
-            ++clock;
-            c.sweep();
-            BEAST_EXPECT(c.getCacheSize() == 0);
-            BEAST_EXPECT(c.size() == 0);
-        }
-
-        {
-            testcase("intrptr");
-
-            struct MyRefCountObject : IntrusiveRefCounts
-            {
-                std::string data;
-
-                // Needed to support weak intrusive pointers
-                virtual void
-                partialDestructor() {};
-
-                MyRefCountObject() = default;
-                explicit MyRefCountObject(std::string data) : data(std::move(data))
-                {
-                }
-
-                bool
-                operator==(std::string const& other) const
-                {
-                    return data == other;
-                }
-            };
-
-            using IntrPtrCache = TaggedCache<
-                Key,
-                MyRefCountObject,
-                /*IsKeyCache*/ false,
-                intr_ptr::SharedWeakUnionPtr<MyRefCountObject>,
-                intr_ptr::SharedPtr<MyRefCountObject>>;
-
-            IntrPtrCache intrPtrCache("IntrPtrTest", 1, 1s, clock, journal);
-
-            intrPtrCache.canonicalizeReplaceCache(1, intr_ptr::makeShared<MyRefCountObject>("one"));
-            BEAST_EXPECT(intrPtrCache.getCacheSize() == 1);
-            BEAST_EXPECT(intrPtrCache.size() == 1);
-
-            {
-                {
-                    intrPtrCache.canonicalizeReplaceCache(
-                        1, intr_ptr::makeShared<MyRefCountObject>("one_replaced"));
-
-                    auto p = intrPtrCache.fetch(1);
-                    BEAST_EXPECT(*p == "one_replaced");
-
-                    // Advance the clock a lot
-                    ++clock;
-                    intrPtrCache.sweep();
-                    BEAST_EXPECT(intrPtrCache.getCacheSize() == 0);
-                    BEAST_EXPECT(intrPtrCache.size() == 1);
-
-                    intrPtrCache.canonicalizeReplaceCache(
-                        1, intr_ptr::makeShared<MyRefCountObject>("one_replaced_2"));
-
-                    auto p2 = intrPtrCache.fetch(1);
-                    BEAST_EXPECT(*p2 == "one_replaced_2");
-
-                    intrPtrCache.del(1, true);
-                }
-
-                intrPtrCache.canonicalizeReplaceCache(
-                    1, intr_ptr::makeShared<MyRefCountObject>("one_replaced_3"));
-                auto p3 = intrPtrCache.fetch(1);
-                BEAST_EXPECT(*p3 == "one_replaced_3");
-            }
-
-            ++clock;
-            intrPtrCache.sweep();
-            BEAST_EXPECT(intrPtrCache.getCacheSize() == 0);
-            BEAST_EXPECT(intrPtrCache.size() == 0);
-        }
-    }
-};
-
-BEAST_DEFINE_TESTSUITE(TaggedCache, basics, xrpl);
-
-}  // namespace xrpl
diff --git a/src/test/basics/Units_test.cpp b/src/test/basics/Units_test.cpp
deleted file mode 100644
index dc780166c6..0000000000
--- a/src/test/basics/Units_test.cpp
+++ /dev/null
@@ -1,344 +0,0 @@
-#include <xrpl/beast/unit_test/suite.h>
-#include <xrpl/beast/utility/Zero.h>
-#include <xrpl/json/json_value.h>
-#include <xrpl/protocol/SystemParameters.h>
-#include <xrpl/protocol/Units.h>
-#include <xrpl/protocol/XRPAmount.h>
-
-#include <cstdint>
-#include <limits>
-#include <type_traits>
-
-namespace xrpl::test {
-
-class units_test : public beast::unit_test::Suite
-{
-private:
-    void
-    testTypes()
-    {
-        using FeeLevel32 = FeeLevel<std::uint32_t>;
-
-        {
-            XRPAmount const x{100};
-            BEAST_EXPECT(x.drops() == 100);
-            BEAST_EXPECT((std::is_same_v<decltype(x)::unit_type, unit::dropTag>));
-            auto y = 4u * x;
-            BEAST_EXPECT(y.value() == 400);
-            BEAST_EXPECT((std::is_same_v<decltype(y)::unit_type, unit::dropTag>));
-
-            auto z = 4 * y;
-            BEAST_EXPECT(z.value() == 1600);
-            BEAST_EXPECT((std::is_same_v<decltype(z)::unit_type, unit::dropTag>));
-
-            FeeLevel32 const f{10};
-            FeeLevel32 const baseFee{100};
-
-            auto drops = mulDiv(baseFee, x, f);
-
-            BEAST_EXPECT(drops);
-            BEAST_EXPECT(drops.value() == 1000);  // NOLINT(bugprone-unchecked-optional-access)
-            BEAST_EXPECT((std::is_same_v<
-                          std::remove_reference_t<decltype(*drops)>::unit_type,
-                          unit::dropTag>));
-
-            BEAST_EXPECT((std::is_same_v<std::remove_reference_t<decltype(*drops)>, XRPAmount>));
-        }
-        {
-            XRPAmount const x{100};
-            BEAST_EXPECT(x.value() == 100);
-            BEAST_EXPECT((std::is_same_v<decltype(x)::unit_type, unit::dropTag>));
-            auto y = 4u * x;
-            BEAST_EXPECT(y.value() == 400);
-            BEAST_EXPECT((std::is_same_v<decltype(y)::unit_type, unit::dropTag>));
-
-            FeeLevel64 const f{10};
-            FeeLevel64 const baseFee{100};
-
-            auto drops = mulDiv(baseFee, x, f);
-
-            BEAST_EXPECT(drops);
-            BEAST_EXPECT(drops.value() == 1000);  // NOLINT(bugprone-unchecked-optional-access)
-            BEAST_EXPECT((std::is_same_v<
-                          std::remove_reference_t<decltype(*drops)>::unit_type,
-                          unit::dropTag>));
-            BEAST_EXPECT((std::is_same_v<std::remove_reference_t<decltype(*drops)>, XRPAmount>));
-        }
-        {
-            FeeLevel64 const x{1024};
-            BEAST_EXPECT(x.value() == 1024);
-            BEAST_EXPECT((std::is_same_v<decltype(x)::unit_type, unit::feelevelTag>));
-            std::uint64_t const m = 4;
-            auto y = m * x;
-            BEAST_EXPECT(y.value() == 4096);
-            BEAST_EXPECT((std::is_same_v<decltype(y)::unit_type, unit::feelevelTag>));
-
-            XRPAmount const basefee{10};
-            FeeLevel64 const referencefee{256};
-
-            auto drops = mulDiv(x, basefee, referencefee);
-
-            BEAST_EXPECT(drops);
-            BEAST_EXPECT(drops.value() == 40);  // NOLINT(bugprone-unchecked-optional-access)
-            BEAST_EXPECT((std::is_same_v<
-                          std::remove_reference_t<decltype(*drops)>::unit_type,
-                          unit::dropTag>));
-            BEAST_EXPECT((std::is_same_v<std::remove_reference_t<decltype(*drops)>, XRPAmount>));
-        }
-    }
-
-    void
-    testJson()
-    {
-        // Json value functionality
-        using FeeLevel32 = FeeLevel<std::uint32_t>;
-
-        {
-            FeeLevel32 const x{std::numeric_limits<std::uint32_t>::max()};
-            auto y = x.jsonClipped();
-            BEAST_EXPECT(y.type() == json::ValueType::UInt);
-            BEAST_EXPECT(y == json::Value{x.fee()});
-        }
-
-        {
-            FeeLevel32 const x{std::numeric_limits<std::uint32_t>::min()};
-            auto y = x.jsonClipped();
-            BEAST_EXPECT(y.type() == json::ValueType::UInt);
-            BEAST_EXPECT(y == json::Value{x.fee()});
-        }
-
-        {
-            FeeLevel64 const x{std::numeric_limits<std::uint64_t>::max()};
-            auto y = x.jsonClipped();
-            BEAST_EXPECT(y.type() == json::ValueType::UInt);
-            BEAST_EXPECT(y == json::Value{std::numeric_limits<std::uint32_t>::max()});
-        }
-
-        {
-            FeeLevel64 const x{std::numeric_limits<std::uint64_t>::min()};
-            auto y = x.jsonClipped();
-            BEAST_EXPECT(y.type() == json::ValueType::UInt);
-            BEAST_EXPECT(y == json::Value{0});
-        }
-
-        {
-            FeeLevelDouble const x{std::numeric_limits<double>::max()};
-            auto y = x.jsonClipped();
-            BEAST_EXPECT(y.type() == json::ValueType::Real);
-            BEAST_EXPECT(y == json::Value{std::numeric_limits<double>::max()});
-        }
-
-        {
-            FeeLevelDouble const x{std::numeric_limits<double>::min()};
-            auto y = x.jsonClipped();
-            BEAST_EXPECT(y.type() == json::ValueType::Real);
-            BEAST_EXPECT(y == json::Value{std::numeric_limits<double>::min()});
-        }
-
-        {
-            XRPAmount const x{std::numeric_limits<std::int64_t>::max()};
-            auto y = x.jsonClipped();
-            BEAST_EXPECT(y.type() == json::ValueType::Int);
-            BEAST_EXPECT(y == json::Value{std::numeric_limits<std::int32_t>::max()});
-        }
-
-        {
-            XRPAmount const x{std::numeric_limits<std::int64_t>::min()};
-            auto y = x.jsonClipped();
-            BEAST_EXPECT(y.type() == json::ValueType::Int);
-            BEAST_EXPECT(y == json::Value{std::numeric_limits<std::int32_t>::min()});
-        }
-    }
-
-    void
-    testFunctions()
-    {
-        // Explicitly test every defined function for the ValueUnit class
-        // since some of them are templated, but not used anywhere else.
-        using FeeLevel32 = FeeLevel<std::uint32_t>;
-
-        {
-            auto make = [&](auto x) -> FeeLevel64 { return x; };
-            auto explicitmake = [&](auto x) -> FeeLevel64 { return FeeLevel64{x}; };
-
-            [[maybe_unused]]
-            FeeLevel64 const defaulted{};
-            FeeLevel64 test{0};
-            BEAST_EXPECT(test.fee() == 0);
-
-            test = explicitmake(beast::kZero);
-            BEAST_EXPECT(test.fee() == 0);
-
-            test = beast::kZero;
-            BEAST_EXPECT(test.fee() == 0);
-
-            test = explicitmake(100u);
-            BEAST_EXPECT(test.fee() == 100);
-
-            FeeLevel64 const targetSame{200u};
-            FeeLevel32 const targetOther{300u};
-            test = make(targetSame);
-            BEAST_EXPECT(test.fee() == 200);
-            BEAST_EXPECT(test == targetSame);
-            BEAST_EXPECT(test < FeeLevel64{1000});
-            BEAST_EXPECT(test > FeeLevel64{100});
-            test = make(targetOther);
-            BEAST_EXPECT(test.fee() == 300);
-            BEAST_EXPECT(test == targetOther);
-
-            test = std::uint64_t(200);
-            BEAST_EXPECT(test.fee() == 200);
-            test = std::uint32_t(300);
-            BEAST_EXPECT(test.fee() == 300);
-
-            test = targetSame;
-            BEAST_EXPECT(test.fee() == 200);
-            test = targetOther.fee();
-            BEAST_EXPECT(test.fee() == 300);
-            BEAST_EXPECT(test == targetOther);
-
-            test = targetSame * 2;
-            BEAST_EXPECT(test.fee() == 400);
-            test = 3 * targetSame;
-            BEAST_EXPECT(test.fee() == 600);
-            test = targetSame / 10;
-            BEAST_EXPECT(test.fee() == 20);
-
-            test += targetSame;
-            BEAST_EXPECT(test.fee() == 220);
-
-            test -= targetSame;
-            BEAST_EXPECT(test.fee() == 20);
-
-            test++;
-            BEAST_EXPECT(test.fee() == 21);
-            ++test;
-            BEAST_EXPECT(test.fee() == 22);
-            test--;
-            BEAST_EXPECT(test.fee() == 21);
-            --test;
-            BEAST_EXPECT(test.fee() == 20);
-
-            test *= 5;
-            BEAST_EXPECT(test.fee() == 100);
-            test /= 2;
-            BEAST_EXPECT(test.fee() == 50);
-            test %= 13;
-            BEAST_EXPECT(test.fee() == 11);
-
-            /*
-            // illegal with unsigned
-            test = -test;
-            BEAST_EXPECT(test.fee() == -11);
-            BEAST_EXPECT(test.signum() == -1);
-            BEAST_EXPECT(to_string(test) == "-11");
-            */
-
-            BEAST_EXPECT(test);
-            test = 0;
-            BEAST_EXPECT(!test);
-            BEAST_EXPECT(test.signum() == 0);
-            test = targetSame;
-            BEAST_EXPECT(test.signum() == 1);
-            BEAST_EXPECT(to_string(test) == "200");
-        }
-        {
-            auto make = [&](auto x) -> FeeLevelDouble { return x; };
-            auto explicitmake = [&](auto x) -> FeeLevelDouble { return FeeLevelDouble{x}; };
-
-            [[maybe_unused]]
-            FeeLevelDouble const defaulted{};
-            FeeLevelDouble test{0};
-            BEAST_EXPECT(test.fee() == 0);
-
-            test = explicitmake(beast::kZero);
-            BEAST_EXPECT(test.fee() == 0);
-
-            test = beast::kZero;
-            BEAST_EXPECT(test.fee() == 0);
-
-            test = explicitmake(100.0);
-            BEAST_EXPECT(test.fee() == 100);
-
-            FeeLevelDouble const targetSame{200.0};
-            FeeLevel64 const targetOther{300};
-            test = make(targetSame);
-            BEAST_EXPECT(test.fee() == 200);
-            BEAST_EXPECT(test == targetSame);
-            BEAST_EXPECT(test < FeeLevelDouble{1000.0});
-            BEAST_EXPECT(test > FeeLevelDouble{100.0});
-            test = targetOther.fee();
-            BEAST_EXPECT(test.fee() == 300);
-            BEAST_EXPECT(test == targetOther);
-
-            test = 200.0;
-            BEAST_EXPECT(test.fee() == 200);
-            test = std::uint64_t(300);
-            BEAST_EXPECT(test.fee() == 300);
-
-            test = targetSame;
-            BEAST_EXPECT(test.fee() == 200);
-
-            test = targetSame * 2;
-            BEAST_EXPECT(test.fee() == 400);
-            test = 3 * targetSame;
-            BEAST_EXPECT(test.fee() == 600);
-            test = targetSame / 10;
-            BEAST_EXPECT(test.fee() == 20);
-
-            test += targetSame;
-            BEAST_EXPECT(test.fee() == 220);
-
-            test -= targetSame;
-            BEAST_EXPECT(test.fee() == 20);
-
-            test++;
-            BEAST_EXPECT(test.fee() == 21);
-            ++test;
-            BEAST_EXPECT(test.fee() == 22);
-            test--;
-            BEAST_EXPECT(test.fee() == 21);
-            --test;
-            BEAST_EXPECT(test.fee() == 20);
-
-            test *= 5;
-            BEAST_EXPECT(test.fee() == 100);
-            test /= 2;
-            BEAST_EXPECT(test.fee() == 50);
-            /* illegal with floating
-            test %= 13;
-            BEAST_EXPECT(test.fee() == 11);
-            */
-
-            // legal with signed
-            test = -test;
-            BEAST_EXPECT(test.fee() == -50);
-            BEAST_EXPECT(test.signum() == -1);
-            BEAST_EXPECT(to_string(test) == "-50.000000");
-
-            BEAST_EXPECT(test);
-            test = 0;
-            BEAST_EXPECT(!test);
-            BEAST_EXPECT(test.signum() == 0);
-            test = targetSame;
-            BEAST_EXPECT(test.signum() == 1);
-            BEAST_EXPECT(to_string(test) == "200.000000");
-        }
-    }
-
-public:
-    void
-    run() override
-    {
-        BEAST_EXPECT(kInitialXrp.drops() == 100'000'000'000'000'000);
-        BEAST_EXPECT(kInitialXrp == XRPAmount{100'000'000'000'000'000});
-
-        testTypes();
-        testJson();
-        testFunctions();
-    }
-};
-
-BEAST_DEFINE_TESTSUITE(units, basics, xrpl);
-
-}  // namespace xrpl::test
diff --git a/src/test/basics/XRPAmount_test.cpp b/src/test/basics/XRPAmount_test.cpp
deleted file mode 100644
index f393003365..0000000000
--- a/src/test/basics/XRPAmount_test.cpp
+++ /dev/null
@@ -1,326 +0,0 @@
-#include <xrpl/beast/unit_test/suite.h>
-#include <xrpl/beast/utility/Zero.h>
-#include <xrpl/protocol/XRPAmount.h>
-
-#include <cstdint>
-#include <limits>
-
-namespace xrpl {
-
-class XRPAmount_test : public beast::unit_test::Suite
-{
-public:
-    void
-    testSigNum()
-    {
-        testcase("signum");
-
-        for (auto i : {-1, 0, 1})
-        {
-            XRPAmount const x(i);
-
-            if (i < 0)
-            {
-                BEAST_EXPECT(x.signum() < 0);
-            }
-            else if (i > 0)
-            {
-                BEAST_EXPECT(x.signum() > 0);
-            }
-            else
-            {
-                BEAST_EXPECT(x.signum() == 0);
-            }
-        }
-    }
-
-    void
-    testBeastZero()
-    {
-        testcase("beast::Zero Comparisons");
-
-        using beast::kZero;
-
-        for (auto i : {-1, 0, 1})
-        {
-            XRPAmount const x(i);
-
-            BEAST_EXPECT((i == 0) == (x == kZero));
-            BEAST_EXPECT((i != 0) == (x != kZero));
-            BEAST_EXPECT((i < 0) == (x < kZero));
-            BEAST_EXPECT((i > 0) == (x > kZero));
-            BEAST_EXPECT((i <= 0) == (x <= kZero));
-            BEAST_EXPECT((i >= 0) == (x >= kZero));
-
-            BEAST_EXPECT((0 == i) == (kZero == x));
-            BEAST_EXPECT((0 != i) == (kZero != x));
-            BEAST_EXPECT((0 < i) == (kZero < x));
-            BEAST_EXPECT((0 > i) == (kZero > x));
-            BEAST_EXPECT((0 <= i) == (kZero <= x));
-            BEAST_EXPECT((0 >= i) == (kZero >= x));
-        }
-    }
-
-    void
-    testComparisons()
-    {
-        testcase("XRP Comparisons");
-
-        for (auto i : {-1, 0, 1})
-        {
-            XRPAmount const x(i);
-
-            for (auto j : {-1, 0, 1})
-            {
-                XRPAmount const y(j);
-
-                BEAST_EXPECT((i == j) == (x == y));
-                BEAST_EXPECT((i != j) == (x != y));
-                BEAST_EXPECT((i < j) == (x < y));
-                BEAST_EXPECT((i > j) == (x > y));
-                BEAST_EXPECT((i <= j) == (x <= y));
-                BEAST_EXPECT((i >= j) == (x >= y));
-            }
-        }
-    }
-
-    void
-    testAddSub()
-    {
-        testcase("Addition & Subtraction");
-
-        for (auto i : {-1, 0, 1})
-        {
-            XRPAmount const x(i);
-
-            for (auto j : {-1, 0, 1})
-            {
-                XRPAmount const y(j);
-
-                BEAST_EXPECT(XRPAmount(i + j) == (x + y));
-                BEAST_EXPECT(XRPAmount(i - j) == (x - y));
-
-                BEAST_EXPECT((x + y) == (y + x));  // addition is commutative
-            }
-        }
-    }
-
-    void
-    testDecimal()
-    {
-        // Tautology
-        BEAST_EXPECT(kDropsPerXrp.decimalXRP() == 1);
-
-        XRPAmount test{1};
-        BEAST_EXPECT(test.decimalXRP() == 0.000001);
-
-        test = -test;
-        BEAST_EXPECT(test.decimalXRP() == -0.000001);
-
-        test = 100'000'000;
-        BEAST_EXPECT(test.decimalXRP() == 100);
-
-        test = -test;
-        BEAST_EXPECT(test.decimalXRP() == -100);
-    }
-
-    void
-    testFunctions()
-    {
-        // Explicitly test every defined function for the XRPAmount class
-        // since some of them are templated, but not used anywhere else.
-        auto make = [&](auto x) -> XRPAmount { return XRPAmount{x}; };
-
-        XRPAmount const defaulted{};
-        (void)defaulted;
-        XRPAmount test{0};
-        BEAST_EXPECT(test.drops() == 0);
-
-        test = make(beast::kZero);
-        BEAST_EXPECT(test.drops() == 0);
-
-        test = beast::kZero;
-        BEAST_EXPECT(test.drops() == 0);
-
-        test = make(100);
-        BEAST_EXPECT(test.drops() == 100);
-
-        test = make(100u);
-        BEAST_EXPECT(test.drops() == 100);
-
-        XRPAmount const targetSame{200u};
-        test = make(targetSame);
-        BEAST_EXPECT(test.drops() == 200);
-        BEAST_EXPECT(test == targetSame);
-        BEAST_EXPECT(test < XRPAmount{1000});
-        BEAST_EXPECT(test > XRPAmount{100});
-
-        test = std::int64_t(200);
-        BEAST_EXPECT(test.drops() == 200);
-        test = std::uint32_t(300);
-        BEAST_EXPECT(test.drops() == 300);
-
-        test = targetSame;
-        BEAST_EXPECT(test.drops() == 200);
-        auto testOther = test.dropsAs<std::uint32_t>();
-        BEAST_EXPECT(testOther);
-        BEAST_EXPECT(*testOther == 200);  // NOLINT(bugprone-unchecked-optional-access)
-        test = std::numeric_limits<std::uint64_t>::max();
-        testOther = test.dropsAs<std::uint32_t>();
-        BEAST_EXPECT(!testOther);
-        test = -1;
-        testOther = test.dropsAs<std::uint32_t>();
-        BEAST_EXPECT(!testOther);
-
-        test = targetSame * 2;
-        BEAST_EXPECT(test.drops() == 400);
-        test = 3 * targetSame;
-        BEAST_EXPECT(test.drops() == 600);
-        test = 20;
-        BEAST_EXPECT(test.drops() == 20);
-
-        test += targetSame;
-        BEAST_EXPECT(test.drops() == 220);
-
-        test -= targetSame;
-        BEAST_EXPECT(test.drops() == 20);
-
-        test *= 5;
-        BEAST_EXPECT(test.drops() == 100);
-        test = 50;
-        BEAST_EXPECT(test.drops() == 50);
-        test -= 39;
-        BEAST_EXPECT(test.drops() == 11);
-
-        // legal with signed
-        test = -test;
-        BEAST_EXPECT(test.drops() == -11);
-        BEAST_EXPECT(test.signum() == -1);
-        BEAST_EXPECT(to_string(test) == "-11");
-
-        BEAST_EXPECT(test);
-        test = 0;
-        BEAST_EXPECT(!test);
-        BEAST_EXPECT(test.signum() == 0);
-        test = targetSame;
-        BEAST_EXPECT(test.signum() == 1);
-        BEAST_EXPECT(to_string(test) == "200");
-    }
-
-    void
-    testMulRatio()
-    {
-        testcase("mulRatio");
-
-        constexpr auto kMaxUInt32 = std::numeric_limits<std::uint32_t>::max();
-        constexpr auto kMaxXrp = std::numeric_limits<XRPAmount::value_type>::max();
-        constexpr auto kMinXrp = std::numeric_limits<XRPAmount::value_type>::min();
-
-        {
-            // multiply by a number that would overflow then divide by the same
-            // number, and check we didn't lose any value
-            XRPAmount big(kMaxXrp);
-            BEAST_EXPECT(big == mulRatio(big, kMaxUInt32, kMaxUInt32, true));
-            // rounding mode shouldn't matter as the result is exact
-            BEAST_EXPECT(big == mulRatio(big, kMaxUInt32, kMaxUInt32, false));
-
-            // multiply and divide by values that would overflow if done
-            // naively, and check that it gives the correct answer
-            big -= 0xf;  // Subtract a little so it's divisible by 4
-            BEAST_EXPECT(mulRatio(big, 3, 4, false).value() == (big.value() / 4) * 3);
-            BEAST_EXPECT(mulRatio(big, 3, 4, true).value() == (big.value() / 4) * 3);
-            BEAST_EXPECT((big.value() * 3) / 4 != (big.value() / 4) * 3);
-        }
-
-        {
-            // Similar test as above, but for negative values
-            XRPAmount big(kMinXrp);  // NOLINT TODO
-            BEAST_EXPECT(big == mulRatio(big, kMaxUInt32, kMaxUInt32, true));
-            // rounding mode shouldn't matter as the result is exact
-            BEAST_EXPECT(big == mulRatio(big, kMaxUInt32, kMaxUInt32, false));
-
-            // multiply and divide by values that would overflow if done
-            // naively, and check that it gives the correct answer
-            BEAST_EXPECT(mulRatio(big, 3, 4, false).value() == (big.value() / 4) * 3);
-            BEAST_EXPECT(mulRatio(big, 3, 4, true).value() == (big.value() / 4) * 3);
-            BEAST_EXPECT((big.value() * 3) / 4 != (big.value() / 4) * 3);
-        }
-
-        {
-            // small amounts
-            XRPAmount const tiny(1);
-            // Round up should give the smallest allowable number
-            BEAST_EXPECT(tiny == mulRatio(tiny, 1, kMaxUInt32, true));
-            // rounding down should be zero
-            BEAST_EXPECT(beast::kZero == mulRatio(tiny, 1, kMaxUInt32, false));
-            BEAST_EXPECT(beast::kZero == mulRatio(tiny, kMaxUInt32 - 1, kMaxUInt32, false));
-
-            // tiny negative numbers
-            XRPAmount const tinyNeg(-1);
-            // Round up should give zero
-            BEAST_EXPECT(beast::kZero == mulRatio(tinyNeg, 1, kMaxUInt32, true));
-            BEAST_EXPECT(beast::kZero == mulRatio(tinyNeg, kMaxUInt32 - 1, kMaxUInt32, true));
-            // rounding down should be tiny
-            BEAST_EXPECT(tinyNeg == mulRatio(tinyNeg, kMaxUInt32 - 1, kMaxUInt32, false));
-        }
-
-        {  // rounding
-            {
-                XRPAmount const one(1);
-                auto const rup = mulRatio(one, kMaxUInt32 - 1, kMaxUInt32, true);
-                auto const rdown = mulRatio(one, kMaxUInt32 - 1, kMaxUInt32, false);
-                BEAST_EXPECT(rup.drops() - rdown.drops() == 1);
-            }
-
-            {
-                XRPAmount const big(kMaxXrp);
-                auto const rup = mulRatio(big, kMaxUInt32 - 1, kMaxUInt32, true);
-                auto const rdown = mulRatio(big, kMaxUInt32 - 1, kMaxUInt32, false);
-                BEAST_EXPECT(rup.drops() - rdown.drops() == 1);
-            }
-
-            {
-                XRPAmount const negOne(-1);
-                auto const rup = mulRatio(negOne, kMaxUInt32 - 1, kMaxUInt32, true);
-                auto const rdown = mulRatio(negOne, kMaxUInt32 - 1, kMaxUInt32, false);
-                BEAST_EXPECT(rup.drops() - rdown.drops() == 1);
-            }
-        }
-
-        {
-            // division by zero
-            XRPAmount one(1);
-            except([&] { mulRatio(one, 1, 0, true); });
-        }
-
-        {
-            // overflow
-            XRPAmount big(kMaxXrp);
-            except([&] { mulRatio(big, 2, 1, true); });
-        }
-
-        {
-            // underflow
-            XRPAmount const bigNegative(kMinXrp + 10);
-            BEAST_EXPECT(mulRatio(bigNegative, 2, 1, true) == kMinXrp);
-        }
-    }  // namespace xrpl
-
-    //--------------------------------------------------------------------------
-
-    void
-    run() override
-    {
-        testSigNum();
-        testBeastZero();
-        testComparisons();
-        testAddSub();
-        testDecimal();
-        testFunctions();
-        testMulRatio();
-    }
-};
-
-BEAST_DEFINE_TESTSUITE(XRPAmount, basics, xrpl);
-
-}  // namespace xrpl
diff --git a/src/test/basics/base58_test.cpp b/src/test/basics/base58_test.cpp
deleted file mode 100644
index 3c76308813..0000000000
--- a/src/test/basics/base58_test.cpp
+++ /dev/null
@@ -1,439 +0,0 @@
-#include <xrpl/beast/unit_test/suite.h>
-#include <xrpl/protocol/detail/token_errors.h>
-
-#include <boost/multiprecision/cpp_int.hpp>  // IWYU pragma: keep
-
-#include <algorithm>
-#include <cassert>
-#include <cstdint>
-#include <cstring>
-#include <iomanip>
-#include <iostream>
-#include <limits>
-#include <stdexcept>
-#include <string>
-#include <tuple>
-#include <vector>
-#ifndef _MSC_VER
-
-#include <xrpl/protocol/detail/b58_utils.h>
-#include <xrpl/protocol/tokens.h>
-
-#include <array>
-#include <cstddef>
-#include <random>
-#include <span>
-#include <sstream>
-
-namespace xrpl::test {
-namespace {
-
-[[nodiscard]] inline auto
-randEngine() -> std::mt19937&
-{
-    static std::mt19937 kR = [] {
-        std::random_device rd;
-        return std::mt19937{rd()};
-    }();
-    return kR;
-}
-
-constexpr int kNumTokenTypeIndexes = 9;
-
-[[nodiscard]] inline auto
-tokenTypeAndSize(int i) -> std::tuple<xrpl::TokenType, std::size_t>
-{
-    assert(i < kNumTokenTypeIndexes);
-
-    switch (i)
-    {
-        using enum xrpl::TokenType;
-        case 0:
-            return {None, 20};
-        case 1:
-            return {NodePublic, 32};
-        case 2:
-            return {NodePublic, 33};
-        case 3:
-            return {NodePrivate, 32};
-        case 4:
-            return {AccountID, 20};
-        case 5:
-            return {AccountPublic, 32};
-        case 6:
-            return {AccountPublic, 33};
-        case 7:
-            return {AccountSecret, 32};
-        case 8:
-            return {FamilySeed, 16};
-        default:
-            throw std::invalid_argument(
-                "Invalid token selection passed to tokenTypeAndSize() "
-                "in " __FILE__);
-    }
-}
-
-[[nodiscard]] inline auto
-randomTokenTypeAndSize() -> std::tuple<xrpl::TokenType, std::size_t>
-{
-    using namespace xrpl;
-    auto& rng = randEngine();
-    std::uniform_int_distribution<> d(0, 8);
-    return tokenTypeAndSize(d(rng));
-}
-
-// Return the token type and subspan of `d` to use as test data.
-[[nodiscard]] inline auto
-randomB256TestData(std::span<std::uint8_t> d)
-    -> std::tuple<xrpl::TokenType, std::span<std::uint8_t>>
-{
-    auto& rng = randEngine();
-    std::uniform_int_distribution<std::uint8_t> dist(0, 255);
-    auto [tokType, tokSize] = randomTokenTypeAndSize();
-    std::generate(d.begin(), d.begin() + tokSize, [&] { return dist(rng); });
-    return {tokType, d.subspan(0, tokSize)};
-}
-
-inline void
-printAsChar(std::span<std::uint8_t> a, std::span<std::uint8_t> b)
-{
-    auto asString = [](std::span<std::uint8_t> s) {
-        std::string r;
-        r.resize(s.size());
-        std::ranges::copy(s, r.begin());
-        return r;
-    };
-    auto sa = asString(a);
-    auto sb = asString(b);
-    std::cerr << "\n\n" << sa << "\n" << sb << "\n";
-}
-
-inline void
-printAsInt(std::span<std::uint8_t> a, std::span<std::uint8_t> b)
-{
-    auto asString = [](std::span<std::uint8_t> s) -> std::string {
-        std::stringstream sstr;
-        for (auto i : s)
-        {
-            sstr << std::setw(3) << int(i) << ',';
-        }
-        return sstr.str();
-    };
-    auto sa = asString(a);
-    auto sb = asString(b);
-    std::cerr << "\n\n" << sa << "\n" << sb << "\n";
-}
-
-}  // namespace
-
-namespace multiprecision_utils {
-
-boost::multiprecision::checked_uint512_t
-toBoostMP(std::span<std::uint64_t> in)
-{
-    boost::multiprecision::checked_uint512_t mbp = 0;
-    for (auto i = in.rbegin(); i != in.rend(); ++i)
-    {
-        mbp <<= 64;
-        mbp += *i;
-    }
-    return mbp;
-}
-
-std::vector<std::uint64_t>
-randomBigInt(std::uint8_t minSize = 1, std::uint8_t maxSize = 5)
-{
-    auto eng = randEngine();
-    std::uniform_int_distribution<std::uint8_t> numCoeffDist(minSize, maxSize);
-    std::uniform_int_distribution<std::uint64_t> dist;
-    auto const numCoeff = numCoeffDist(eng);
-    std::vector<std::uint64_t> coeffs;
-    coeffs.reserve(numCoeff);
-    for (int i = 0; i < numCoeff; ++i)
-    {
-        coeffs.push_back(dist(eng));
-    }
-    return coeffs;
-}
-}  // namespace multiprecision_utils
-
-class base58_test : public beast::unit_test::Suite
-{
-    void
-    testMultiprecision()
-    {
-        testcase("b58_multiprecision");
-
-        using namespace boost::multiprecision;
-
-        static constexpr std::size_t kIters = 100000;
-        auto eng = randEngine();
-        std::uniform_int_distribution<std::uint64_t> dist;
-        std::uniform_int_distribution<std::uint64_t> dist1(1);
-        for (int i = 0; i < kIters; ++i)
-        {
-            std::uint64_t const d = dist(eng);
-            if (d == 0u)
-                continue;
-            auto bigInt = multiprecision_utils::randomBigInt();
-            auto const boostBigInt = multiprecision_utils::toBoostMP(
-                std::span<std::uint64_t>(bigInt.data(), bigInt.size()));
-
-            auto const refDiv = boostBigInt / d;
-            auto const refMod = boostBigInt % d;
-
-            auto const mod = b58_fast::detail::inplaceBigintDivRem(
-                std::span<uint64_t>(bigInt.data(), bigInt.size()), d);
-            auto const foundDiv = multiprecision_utils::toBoostMP(bigInt);
-            BEAST_EXPECT(refMod.convert_to<std::uint64_t>() == mod);
-            BEAST_EXPECT(foundDiv == refDiv);
-        }
-        for (int i = 0; i < kIters; ++i)
-        {
-            std::uint64_t const d = dist(eng);
-            auto bigInt = multiprecision_utils::randomBigInt(/*minSize*/ 2);
-            if (bigInt[bigInt.size() - 1] == std::numeric_limits<std::uint64_t>::max())
-            {
-                bigInt[bigInt.size() - 1] -= 1;  // Prevent overflow
-            }
-            auto const boostBigInt = multiprecision_utils::toBoostMP(
-                std::span<std::uint64_t>(bigInt.data(), bigInt.size()));
-
-            auto const refAdd = boostBigInt + d;
-
-            auto const result = b58_fast::detail::inplaceBigintAdd(
-                std::span<uint64_t>(bigInt.data(), bigInt.size()), d);
-            BEAST_EXPECT(result == TokenCodecErrc::Success);
-            auto const foundAdd = multiprecision_utils::toBoostMP(bigInt);
-            BEAST_EXPECT(refAdd == foundAdd);
-        }
-        for (int i = 0; i < kIters; ++i)
-        {
-            std::uint64_t const d = dist1(eng);
-            // Force overflow
-            std::vector<std::uint64_t> bigInt(5, std::numeric_limits<std::uint64_t>::max());
-
-            auto const boostBigInt = multiprecision_utils::toBoostMP(
-                std::span<std::uint64_t>(bigInt.data(), bigInt.size()));
-
-            auto const refAdd = boostBigInt + d;
-
-            auto const result = b58_fast::detail::inplaceBigintAdd(
-                std::span<uint64_t>(bigInt.data(), bigInt.size()), d);
-            BEAST_EXPECT(result == TokenCodecErrc::OverflowAdd);
-            auto const foundAdd = multiprecision_utils::toBoostMP(bigInt);
-            BEAST_EXPECT(refAdd != foundAdd);
-        }
-        for (int i = 0; i < kIters; ++i)
-        {
-            std::uint64_t const d = dist(eng);
-            auto bigInt = multiprecision_utils::randomBigInt(/* minSize */ 2);
-            // inplace mul requires the most significant coeff to be zero to
-            // hold the result.
-            bigInt[bigInt.size() - 1] = 0;
-            auto const boostBigInt = multiprecision_utils::toBoostMP(
-                std::span<std::uint64_t>(bigInt.data(), bigInt.size()));
-
-            auto const refMul = boostBigInt * d;
-
-            auto const result = b58_fast::detail::inplaceBigintMul(
-                std::span<uint64_t>(bigInt.data(), bigInt.size()), d);
-            BEAST_EXPECT(result == TokenCodecErrc::Success);
-            auto const foundMul = multiprecision_utils::toBoostMP(bigInt);
-            BEAST_EXPECT(refMul == foundMul);
-        }
-        for (int i = 0; i < kIters; ++i)
-        {
-            std::uint64_t const d = dist1(eng);
-            // Force overflow
-            std::vector<std::uint64_t> bigInt(5, std::numeric_limits<std::uint64_t>::max());
-            auto const boostBigInt = multiprecision_utils::toBoostMP(
-                std::span<std::uint64_t>(bigInt.data(), bigInt.size()));
-
-            auto const refMul = boostBigInt * d;
-
-            auto const result = b58_fast::detail::inplaceBigintMul(
-                std::span<uint64_t>(bigInt.data(), bigInt.size()), d);
-            BEAST_EXPECT(result == TokenCodecErrc::InputTooLarge);
-            auto const foundMul = multiprecision_utils::toBoostMP(bigInt);
-            BEAST_EXPECT(refMul != foundMul);
-        }
-    }
-
-    void
-    testFastMatchesRef()
-    {
-        testcase("fast_matches_ref");
-        auto testRawEncode = [&](std::span<std::uint8_t> const& b256Data) {
-            std::array<std::uint8_t, 64> b58ResultBuf[2];
-            std::array<std::span<std::uint8_t>, 2> b58Result;
-
-            std::array<std::uint8_t, 64> b256ResultBuf[2];
-            std::array<std::span<std::uint8_t>, 2> b256Result;
-            for (int i = 0; i < 2; ++i)
-            {
-                std::span const outBuf{b58ResultBuf[i]};
-                if (i == 0)
-                {
-                    auto const r = xrpl::b58_fast::detail::b256ToB58Be(b256Data, outBuf);
-                    BEAST_EXPECT(r);
-                    b58Result[i] = r.value();
-                }
-                else
-                {
-                    std::array<std::uint8_t, 128> tmpBuf{};
-                    std::string const s = xrpl::b58_ref::detail::encodeBase58(
-                        b256Data.data(), b256Data.size(), tmpBuf.data(), tmpBuf.size());
-                    BEAST_EXPECT(s.size());
-                    b58Result[i] = outBuf.subspan(0, s.size());
-                    std::ranges::copy(s, b58Result[i].begin());
-                }
-            }
-            if (BEAST_EXPECT(b58Result[0].size() == b58Result[1].size()))
-            {
-                if (!BEAST_EXPECT(
-                        memcmp(b58Result[0].data(), b58Result[1].data(), b58Result[0].size()) == 0))
-                {
-                    printAsChar(b58Result[0], b58Result[1]);
-                }
-            }
-
-            for (int i = 0; i < 2; ++i)
-            {
-                std::span const outBuf{b256ResultBuf[i].data(), b256ResultBuf[i].size()};
-                if (i == 0)
-                {
-                    std::string const in(
-                        b58Result[i].data(), b58Result[i].data() + b58Result[i].size());
-                    auto const r = xrpl::b58_fast::detail::b58ToB256Be(in, outBuf);
-                    BEAST_EXPECT(r);
-                    b256Result[i] = r.value();
-                }
-                else
-                {
-                    std::string const st(b58Result[i].begin(), b58Result[i].end());
-                    std::string const s = xrpl::b58_ref::detail::decodeBase58(st);
-                    BEAST_EXPECT(s.size());
-                    b256Result[i] = outBuf.subspan(0, s.size());
-                    std::ranges::copy(s, b256Result[i].begin());
-                }
-            }
-
-            if (BEAST_EXPECT(b256Result[0].size() == b256Result[1].size()))
-            {
-                if (!BEAST_EXPECT(
-                        memcmp(b256Result[0].data(), b256Result[1].data(), b256Result[0].size()) ==
-                        0))
-                {
-                    printAsInt(b256Result[0], b256Result[1]);
-                }
-            }
-        };
-
-        auto testTokenEncode = [&](xrpl::TokenType const tokType,
-                                   std::span<std::uint8_t> const& b256Data) {
-            std::array<std::uint8_t, 64> b58ResultBuf[2];
-            std::array<std::span<std::uint8_t>, 2> b58Result;
-
-            std::array<std::uint8_t, 64> b256ResultBuf[2];
-            std::array<std::span<std::uint8_t>, 2> b256Result;
-            for (int i = 0; i < 2; ++i)
-            {
-                std::span const outBuf{b58ResultBuf[i].data(), b58ResultBuf[i].size()};
-                if (i == 0)
-                {
-                    auto const r = xrpl::b58_fast::encodeBase58Token(tokType, b256Data, outBuf);
-                    BEAST_EXPECT(r);
-                    b58Result[i] = r.value();
-                }
-                else
-                {
-                    std::string const s =
-                        xrpl::b58_ref::encodeBase58Token(tokType, b256Data.data(), b256Data.size());
-                    BEAST_EXPECT(s.size());
-                    b58Result[i] = outBuf.subspan(0, s.size());
-                    std::ranges::copy(s, b58Result[i].begin());
-                }
-            }
-            if (BEAST_EXPECT(b58Result[0].size() == b58Result[1].size()))
-            {
-                if (!BEAST_EXPECT(
-                        memcmp(b58Result[0].data(), b58Result[1].data(), b58Result[0].size()) == 0))
-                {
-                    printAsChar(b58Result[0], b58Result[1]);
-                }
-            }
-
-            for (int i = 0; i < 2; ++i)
-            {
-                std::span const outBuf{b256ResultBuf[i].data(), b256ResultBuf[i].size()};
-                if (i == 0)
-                {
-                    std::string const in(
-                        b58Result[i].data(), b58Result[i].data() + b58Result[i].size());
-                    auto const r = xrpl::b58_fast::decodeBase58Token(tokType, in, outBuf);
-                    BEAST_EXPECT(r);
-                    b256Result[i] = r.value();
-                }
-                else
-                {
-                    std::string const st(b58Result[i].begin(), b58Result[i].end());
-                    std::string const s = xrpl::b58_ref::decodeBase58Token(st, tokType);
-                    BEAST_EXPECT(s.size());
-                    b256Result[i] = outBuf.subspan(0, s.size());
-                    std::ranges::copy(s, b256Result[i].begin());
-                }
-            }
-
-            if (BEAST_EXPECT(b256Result[0].size() == b256Result[1].size()))
-            {
-                if (!BEAST_EXPECT(
-                        memcmp(b256Result[0].data(), b256Result[1].data(), b256Result[0].size()) ==
-                        0))
-                {
-                    printAsInt(b256Result[0], b256Result[1]);
-                }
-            }
-        };
-
-        auto testIt = [&](xrpl::TokenType const tokType, std::span<std::uint8_t> const& b256Data) {
-            testRawEncode(b256Data);
-            testTokenEncode(tokType, b256Data);
-        };
-
-        // test every token type with data where every byte is the same and the
-        // bytes range from 0-255
-        for (int i = 0; i < kNumTokenTypeIndexes; ++i)
-        {
-            std::array<std::uint8_t, 128> b256DataBuf{};
-            auto const [tokType, tokSize] = tokenTypeAndSize(i);
-            for (int d = 0; d <= 255; ++d)
-            {
-                memset(b256DataBuf.data(), d, tokSize);
-                testIt(tokType, std::span(b256DataBuf.data(), tokSize));
-            }
-        }
-
-        // test with random data
-        static constexpr std::size_t kIters = 100000;
-        for (int i = 0; i < kIters; ++i)
-        {
-            std::array<std::uint8_t, 128> b256DataBuf{};
-            auto const [tokType, b256Data] = randomB256TestData(b256DataBuf);
-            testIt(tokType, b256Data);
-        }
-    }
-
-    void
-    run() override
-    {
-        testMultiprecision();
-        testFastMatchesRef();
-    }
-};
-
-BEAST_DEFINE_TESTSUITE(base58, basics, xrpl);
-
-}  // namespace xrpl::test
-
-#endif  // _MSC_VER
diff --git a/src/test/basics/base_uint_test.cpp b/src/test/basics/base_uint_test.cpp
deleted file mode 100644
index c6572a0028..0000000000
--- a/src/test/basics/base_uint_test.cpp
+++ /dev/null
@@ -1,376 +0,0 @@
-#include <xrpl/basics/Blob.h>
-#include <xrpl/basics/base_uint.h>
-#include <xrpl/basics/hardened_hash.h>
-#include <xrpl/beast/unit_test/suite.h>
-#include <xrpl/beast/utility/Zero.h>
-
-#include <boost/endian/detail/order.hpp>
-
-#include <array>
-#include <cassert>
-#include <complex>
-#include <cstddef>
-#include <cstdint>
-#include <iterator>
-#include <stdexcept>
-#include <string_view>
-#include <type_traits>
-#include <unordered_set>
-#include <utility>
-#include <vector>
-
-namespace xrpl::test {
-
-// a non-hashing Hasher that just copies the bytes.
-// Used to test hash_append in base_uint
-template <std::size_t Bits>
-struct Nonhash
-{
-    static constexpr auto kEndian = boost::endian::order::big;
-    static constexpr std::size_t kWidth = Bits / 8;
-
-    std::array<std::uint8_t, kWidth> data;
-
-    Nonhash() = default;
-
-    void
-    operator()(void const* key, std::size_t len) noexcept
-    {
-        assert(len == kWidth);
-        memcpy(data.data(), key, len);
-    }
-
-    explicit
-    operator std::size_t() noexcept
-    {
-        return kWidth;
-    }
-};
-
-struct base_uint_test : beast::unit_test::Suite
-{
-    using test96 = BaseUInt<96>;
-    static_assert(std::is_copy_constructible_v<test96>);
-    static_assert(std::is_copy_assignable_v<test96>);
-
-    void
-    testComparisons()
-    {
-        {
-            static constexpr std::array<std::pair<std::string_view, std::string_view>, 6> kTestArgs{
-                {{"0000000000000000", "0000000000000001"},
-                 {"0000000000000000", "ffffffffffffffff"},
-                 {"1234567812345678", "2345678923456789"},
-                 {"8000000000000000", "8000000000000001"},
-                 {"aaaaaaaaaaaaaaa9", "aaaaaaaaaaaaaaaa"},
-                 {"fffffffffffffffe", "ffffffffffffffff"}}};
-
-            for (auto const& arg : kTestArgs)
-            {
-                xrpl::BaseUInt<64> const u{arg.first}, v{arg.second};
-                BEAST_EXPECT(u < v);
-                BEAST_EXPECT(u <= v);
-                BEAST_EXPECT(u != v);
-                BEAST_EXPECT(!(u == v));
-                BEAST_EXPECT(!(u > v));
-                BEAST_EXPECT(!(u >= v));
-                BEAST_EXPECT(!(v < u));
-                BEAST_EXPECT(!(v <= u));
-                BEAST_EXPECT(v != u);
-                BEAST_EXPECT(!(v == u));
-                BEAST_EXPECT(v > u);
-                BEAST_EXPECT(v >= u);
-                BEAST_EXPECT(u == u);
-                BEAST_EXPECT(v == v);
-            }
-        }
-
-        {
-            static constexpr std::array<std::pair<std::string_view, std::string_view>, 6> kTestArgs{
-                {
-                    {"000000000000000000000000", "000000000000000000000001"},
-                    {"000000000000000000000000", "ffffffffffffffffffffffff"},
-                    {"0123456789ab0123456789ab", "123456789abc123456789abc"},
-                    {"555555555555555555555555", "55555555555a555555555555"},
-                    {"aaaaaaaaaaaaaaa9aaaaaaaa", "aaaaaaaaaaaaaaaaaaaaaaaa"},
-                    {"fffffffffffffffffffffffe", "ffffffffffffffffffffffff"},
-                }};
-
-            for (auto const& arg : kTestArgs)
-            {
-                xrpl::BaseUInt<96> const u{arg.first}, v{arg.second};
-                BEAST_EXPECT(u < v);
-                BEAST_EXPECT(u <= v);
-                BEAST_EXPECT(u != v);
-                BEAST_EXPECT(!(u == v));
-                BEAST_EXPECT(!(u > v));
-                BEAST_EXPECT(!(u >= v));
-                BEAST_EXPECT(!(v < u));
-                BEAST_EXPECT(!(v <= u));
-                BEAST_EXPECT(v != u);
-                BEAST_EXPECT(!(v == u));
-                BEAST_EXPECT(v > u);
-                BEAST_EXPECT(v >= u);
-                BEAST_EXPECT(u == u);
-                BEAST_EXPECT(v == v);
-            }
-        }
-    }
-
-    void
-    testFromRawSizeMismatch()
-    {
-        testcase("base_uint: fromRaw size mismatch");
-
-        // Container larger than the base_uint (16 bytes vs 12 bytes for test96).
-        // Only the first 12 bytes are copied; the extra bytes are ignored.
-        {
-            Blob const tooBig{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16};
-            test96 const result = test96::fromRaw(tooBig);
-            BEAST_EXPECT(to_string(result) == "0102030405060708090A0B0C");
-        }
-    }
-
-    void
-    run() override
-    {
-        testcase("base_uint: general purpose tests");
-
-#ifdef NDEBUG
-        testFromRawSizeMismatch();
-#endif
-
-        static_assert(!std::is_constructible_v<test96, std::complex<double>>);
-        static_assert(!std::is_assignable_v<test96&, std::complex<double>>);
-
-        testComparisons();
-
-        // used to verify set insertion (hashing required)
-        std::unordered_set<test96, HardenedHash<>> uset;
-
-        Blob const raw{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};
-        BEAST_EXPECT(test96::kBytes == raw.size());
-
-        test96 u = test96::fromRaw(raw);
-        uset.insert(u);
-        BEAST_EXPECT(raw.size() == u.size());
-        BEAST_EXPECT(to_string(u) == "0102030405060708090A0B0C");
-        BEAST_EXPECT(toShortString(u) == "01020304...");
-        BEAST_EXPECT(*u.data() == 1);
-        BEAST_EXPECT(u.signum() == 1);
-        BEAST_EXPECT(!!u);
-        BEAST_EXPECT(!u.isZero());
-        BEAST_EXPECT(u.isNonZero());
-        unsigned char t = 0;
-        for (auto& d : u)
-        {
-            BEAST_EXPECT(d == ++t);
-        }
-
-        // Test hash_append by "hashing" with a no-op hasher (h)
-        // and then extracting the bytes that were written during hashing
-        // back into another base_uint (w) for comparison with the original
-        Nonhash<96> h{};
-        hash_append(h, u);
-        test96 const w = test96::fromRaw(std::vector<std::uint8_t>(h.data.begin(), h.data.end()));
-        BEAST_EXPECT(w == u);
-
-        test96 v{~u};
-        uset.insert(v);
-        BEAST_EXPECT(to_string(v) == "FEFDFCFBFAF9F8F7F6F5F4F3");
-        BEAST_EXPECT(toShortString(v) == "FEFDFCFB...");
-        BEAST_EXPECT(*v.data() == 0xfe);
-        BEAST_EXPECT(v.signum() == 1);
-        BEAST_EXPECT(!!v);
-        BEAST_EXPECT(!v.isZero());
-        BEAST_EXPECT(v.isNonZero());
-        t = 0xff;
-        for (auto& d : v)
-        {
-            BEAST_EXPECT(d == --t);
-        }
-
-        BEAST_EXPECT(u < v);
-        BEAST_EXPECT(v > u);
-
-        v = u;
-        BEAST_EXPECT(v == u);
-
-        test96 z{beast::kZero};
-        uset.insert(z);
-        BEAST_EXPECT(to_string(z) == "000000000000000000000000");
-        BEAST_EXPECT(toShortString(z) == "00000000...");
-        BEAST_EXPECT(*z.data() == 0);
-        BEAST_EXPECT(*z.begin() == 0);
-        BEAST_EXPECT(*std::prev(z.end(), 1) == 0);
-        BEAST_EXPECT(z.signum() == 0);
-        BEAST_EXPECT(!z);
-        BEAST_EXPECT(z.isZero());
-        BEAST_EXPECT(!z.isNonZero());
-        for (auto& d : z)
-        {
-            BEAST_EXPECT(d == 0);
-        }
-
-        test96 n{z};
-        n++;
-        BEAST_EXPECT(n == test96(1));
-        n--;
-        BEAST_EXPECT(n == beast::kZero);
-        BEAST_EXPECT(n == z);
-        n--;
-        BEAST_EXPECT(to_string(n) == "FFFFFFFFFFFFFFFFFFFFFFFF");
-        BEAST_EXPECT(toShortString(n) == "FFFFFFFF...");
-        n = beast::kZero;
-        BEAST_EXPECT(n == z);
-
-        test96 zp1{z};
-        zp1++;
-        test96 zm1{z};
-        zm1--;
-        test96 const x{zm1 ^ zp1};
-        uset.insert(x);
-        BEAST_EXPECTS(to_string(x) == "FFFFFFFFFFFFFFFFFFFFFFFE", to_string(x));
-        BEAST_EXPECTS(toShortString(x) == "FFFFFFFF...", toShortString(x));
-
-        BEAST_EXPECT(uset.size() == 4);
-
-        test96 tmp;
-        BEAST_EXPECT(tmp.parseHex(to_string(u)));
-        BEAST_EXPECT(tmp == u);
-        tmp = z;
-
-        // fails with extra char
-        BEAST_EXPECT(!tmp.parseHex("A" + to_string(u)));
-        tmp = z;
-
-        // fails with extra char at end
-        BEAST_EXPECT(!tmp.parseHex(to_string(u) + "A"));
-
-        // fails with a non-hex character at some point in the string:
-        tmp = z;
-
-        for (std::size_t i = 0; i != 24; ++i)
-        {
-            std::string x = to_string(z);
-            x[i] = ('G' + (i % 10));
-            BEAST_EXPECT(!tmp.parseHex(x));
-        }
-
-        // Walking 1s:
-        for (std::size_t i = 0; i != 24; ++i)
-        {
-            std::string s1 = "000000000000000000000000";
-            s1[i] = '1';
-
-            BEAST_EXPECT(tmp.parseHex(s1));
-            BEAST_EXPECT(to_string(tmp) == s1);
-        }
-
-        // Walking 0s:
-        for (std::size_t i = 0; i != 24; ++i)
-        {
-            std::string s1 = "111111111111111111111111";
-            s1[i] = '0';
-
-            BEAST_EXPECT(tmp.parseHex(s1));
-            BEAST_EXPECT(to_string(tmp) == s1);
-        }
-
-        // Constexpr constructors
-        {
-            static_assert(test96{}.signum() == 0);
-            static_assert(test96("0").signum() == 0);
-            static_assert(test96("000000000000000000000000").signum() == 0);
-            static_assert(test96("000000000000000000000001").signum() == 1);
-            static_assert(test96("800000000000000000000000").signum() == 1);
-
-// Everything within the #if should fail during compilation.
-#if 0
-            // Too few characters
-            static_assert(test96("00000000000000000000000").signum() == 0);
-
-            // Too many characters
-            static_assert(test96("0000000000000000000000000").signum() == 0);
-
-            // Non-hex characters
-            static_assert(test96("00000000000000000000000 ").signum() == 1);
-            static_assert(test96("00000000000000000000000/").signum() == 1);
-            static_assert(test96("00000000000000000000000:").signum() == 1);
-            static_assert(test96("00000000000000000000000@").signum() == 1);
-            static_assert(test96("00000000000000000000000G").signum() == 1);
-            static_assert(test96("00000000000000000000000`").signum() == 1);
-            static_assert(test96("00000000000000000000000g").signum() == 1);
-            static_assert(test96("00000000000000000000000~").signum() == 1);
-#endif  // 0
-
-            // Using the constexpr constructor in a non-constexpr context
-            // with an error in the parsing throws an exception.
-            {
-                // Invalid length for string.
-                bool caught = false;
-                try
-                {
-                    // Try to prevent constant evaluation.
-                    std::vector<char> str(23, '7');
-                    std::string_view const sView(str.data(), str.size());
-                    [[maybe_unused]] test96 const t96(sView);
-                }
-                catch (std::invalid_argument const& e)
-                {
-                    BEAST_EXPECT(e.what() == std::string("invalid length for hex string"));
-                    caught = true;
-                }
-                BEAST_EXPECT(caught);
-            }
-            {
-                // Invalid character in string.
-                bool caught = false;
-                try
-                {
-                    // Try to prevent constant evaluation.
-                    std::vector<char> str(23, '7');
-                    str.push_back('G');
-                    std::string_view const sView(str.data(), str.size());
-                    [[maybe_unused]] test96 const t96(sView);
-                }
-                catch (std::range_error const& e)
-                {
-                    BEAST_EXPECT(e.what() == std::string("invalid hex character"));
-                    caught = true;
-                }
-                BEAST_EXPECT(caught);
-            }
-
-            // Verify that constexpr base_uints interpret a string the same
-            // way parseHex() does.
-            struct StrBaseUInt
-            {
-                char const* const str;
-                test96 tst;
-
-                constexpr StrBaseUInt(char const* s) : str(s), tst(s)
-                {
-                }
-            };
-            static constexpr StrBaseUInt kTestCases[] = {
-                "000000000000000000000000",
-                "000000000000000000000001",
-                "fedcba9876543210ABCDEF91",
-                "19FEDCBA0123456789abcdef",
-                "800000000000000000000000",
-                "fFfFfFfFfFfFfFfFfFfFfFfF"};
-
-            for (StrBaseUInt const& t : kTestCases)
-            {
-                test96 t96;
-                BEAST_EXPECT(t96.parseHex(t.str));
-                BEAST_EXPECT(t96 == t.tst);
-            }
-        }
-    }
-};
-
-BEAST_DEFINE_TESTSUITE(base_uint, basics, xrpl);
-
-}  // namespace xrpl::test
diff --git a/src/test/basics/join_test.cpp b/src/test/basics/join_test.cpp
deleted file mode 100644
index 1ee81f786a..0000000000
--- a/src/test/basics/join_test.cpp
+++ /dev/null
@@ -1,83 +0,0 @@
-#include <test/jtx/Account.h>
-
-#include <xrpl/basics/base_uint.h>
-#include <xrpl/basics/join.h>
-#include <xrpl/beast/unit_test/suite.h>
-
-#include <array>
-#include <cstddef>
-#include <initializer_list>
-#include <sstream>
-#include <string>
-#include <vector>
-
-namespace xrpl::test {
-
-struct join_test : beast::unit_test::Suite
-{
-    void
-    run() override
-    {
-        auto test = [this](auto collectionanddelimiter, std::string expected) {
-            std::stringstream ss;
-            // Put something else in the buffer before and after to ensure that
-            // the << operator returns the stream correctly.
-            ss << "(" << collectionanddelimiter << ")";
-            auto const str = ss.str();
-            BEAST_EXPECT(str.substr(1, str.length() - 2) == expected);
-            BEAST_EXPECT(str.front() == '(');
-            BEAST_EXPECT(str.back() == ')');
-        };
-
-        // C++ array
-        test(CollectionAndDelimiter(std::array<int, 4>{2, -1, 5, 10}, "/"), "2/-1/5/10");
-        // One item C++ array edge case
-        test(CollectionAndDelimiter(std::array<std::string, 1>{"test"}, " & "), "test");
-        // Empty C++ array edge case
-        test(CollectionAndDelimiter(std::array<int, 0>{}, ","), "");
-        {
-            // C-style array
-            char letters[4]{'w', 'a', 's', 'd'};
-            test(CollectionAndDelimiter(letters, std::to_string(0)), "w0a0s0d");
-        }
-        {
-            // Auto sized C-style array
-            std::string words[]{"one", "two", "three", "four"};
-            test(CollectionAndDelimiter(words, "\n"), "one\ntwo\nthree\nfour");
-        }
-        {
-            // One item C-style array edge case
-            std::string words[]{"thing"};
-            test(CollectionAndDelimiter(words, "\n"), "thing");
-        }
-        // Initializer list
-        test(CollectionAndDelimiter(std::initializer_list<size_t>{19, 25}, "+"), "19+25");
-        // vector
-        test(CollectionAndDelimiter(std::vector<int>{0, 42}, std::to_string(99)), "09942");
-        {
-            // vector with one item edge case
-            using namespace jtx;
-            test(
-                CollectionAndDelimiter(std::vector<Account>{Account::kMaster}, "xxx"),
-                Account::kMaster.human());
-        }
-        // empty vector edge case
-        test(CollectionAndDelimiter(std::vector<uint256>{}, ","), "");
-        // C-style string
-        test(CollectionAndDelimiter("string", " "), "s t r i n g");
-        // Empty C-style string edge case
-        test(CollectionAndDelimiter("", "*"), "");
-        // Single char C-style string edge case
-        test(CollectionAndDelimiter("x", "*"), "x");
-        // std::string
-        test(CollectionAndDelimiter(std::string{"string"}, "-"), "s-t-r-i-n-g");
-        // Empty std::string edge case
-        test(CollectionAndDelimiter(std::string{""}, "*"), "");
-        // Single char std::string edge case
-        test(CollectionAndDelimiter(std::string{"y"}, "*"), "y");
-    }
-};  // namespace test
-
-BEAST_DEFINE_TESTSUITE(join, basics, xrpl);
-
-}  // namespace xrpl::test
diff --git a/src/test/beast/aged_associative_container_test.cpp b/src/test/beast/aged_associative_container_test.cpp
index df61824c99..76be44b793 100644
--- a/src/test/beast/aged_associative_container_test.cpp
+++ b/src/test/beast/aged_associative_container_test.cpp
@@ -145,7 +145,7 @@ public:
         }
 
         T*
-        allocate(std::size_t n, T const* = 0)
+        allocate(std::size_t n, T const* = nullptr)
         {
             return static_cast<T*>(::operator new(n * sizeof(T)));
         }
@@ -404,23 +404,27 @@ public:
     //--------------------------------------------------------------------------
 
     template <class Container, class Values>
-    std::enable_if_t<Container::is_map::value && !Container::is_multi::value>
-    checkMapContents(Container& c, Values const& v);
+    void
+    checkMapContents(Container& c, Values const& v)
+        requires(Container::is_map::value && !Container::is_multi::value);
 
     template <class Container, class Values>
-    std::enable_if_t<!(Container::is_map::value && !Container::is_multi::value)>
+    void
     checkMapContents(Container, Values const&)
+        requires(!(Container::is_map::value && !Container::is_multi::value))
     {
     }
 
     // unordered
     template <class C, class Values>
-    std::enable_if_t<std::remove_reference_t<C>::is_unordered::value>
-    checkUnorderedContentsRefRef(C&& c, Values const& v);
+    void
+    checkUnorderedContentsRefRef(C&& c, Values const& v)
+        requires(std::remove_reference_t<C>::is_unordered::value);
 
     template <class C, class Values>
-    std::enable_if_t<!std::remove_reference_t<C>::is_unordered::value>
+    void
     checkUnorderedContentsRefRef(C&&, Values const&)
+        requires(!std::remove_reference_t<C>::is_unordered::value)
     {
     }
 
@@ -440,33 +444,39 @@ public:
 
     // ordered
     template <bool IsUnordered, bool IsMulti, bool IsMap>
-    std::enable_if_t<!IsUnordered>
-    testConstructEmpty();
+    void
+    testConstructEmpty()
+        requires(!IsUnordered);
 
     // unordered
     template <bool IsUnordered, bool IsMulti, bool IsMap>
-    std::enable_if_t<IsUnordered>
-    testConstructEmpty();
+    void
+    testConstructEmpty()
+        requires IsUnordered;
 
     // ordered
     template <bool IsUnordered, bool IsMulti, bool IsMap>
-    std::enable_if_t<!IsUnordered>
-    testConstructRange();
+    void
+    testConstructRange()
+        requires(!IsUnordered);
 
     // unordered
     template <bool IsUnordered, bool IsMulti, bool IsMap>
-    std::enable_if_t<IsUnordered>
-    testConstructRange();
+    void
+    testConstructRange()
+        requires IsUnordered;
 
     // ordered
     template <bool IsUnordered, bool IsMulti, bool IsMap>
-    std::enable_if_t<!IsUnordered>
-    testConstructInitList();
+    void
+    testConstructInitList()
+        requires(!IsUnordered);
 
     // unordered
     template <bool IsUnordered, bool IsMulti, bool IsMap>
-    std::enable_if_t<IsUnordered>
-    testConstructInitList();
+    void
+    testConstructInitList()
+        requires IsUnordered;
 
     //--------------------------------------------------------------------------
 
@@ -482,12 +492,14 @@ public:
 
     // Unordered containers don't have reverse iterators
     template <bool IsUnordered, bool IsMulti, bool IsMap>
-    std::enable_if_t<!IsUnordered>
-    testReverseIterator();
+    void
+    testReverseIterator()
+        requires(!IsUnordered);
 
     template <bool IsUnordered, bool IsMulti, bool IsMap>
-    std::enable_if_t<IsUnordered>
+    void
     testReverseIterator()
+        requires IsUnordered
     {
     }
 
@@ -531,12 +543,14 @@ public:
 
     // map, unordered_map
     template <bool IsUnordered, bool IsMulti, bool IsMap>
-    std::enable_if_t<IsMap && !IsMulti>
-    testArrayCreate();
+    void
+    testArrayCreate()
+        requires(IsMap && !IsMulti);
 
     template <bool IsUnordered, bool IsMulti, bool IsMap>
-    std::enable_if_t<!IsMap || IsMulti>
+    void
     testArrayCreate()
+        requires(!IsMap || IsMulti)
     {
     }
 
@@ -575,12 +589,14 @@ public:
 
     // ordered
     template <bool IsUnordered, bool IsMulti, bool IsMap>
-    std::enable_if_t<!IsUnordered>
-    testCompare();
+    void
+    testCompare()
+        requires(!IsUnordered);
 
     template <bool IsUnordered, bool IsMulti, bool IsMap>
-    std::enable_if_t<IsUnordered>
+    void
     testCompare()
+        requires IsUnordered
     {
     }
 
@@ -588,13 +604,15 @@ public:
 
     // ordered
     template <bool IsUnordered, bool IsMulti, bool IsMap>
-    std::enable_if_t<!IsUnordered>
-    testObservers();
+    void
+    testObservers()
+        requires(!IsUnordered);
 
     // unordered
     template <bool IsUnordered, bool IsMulti, bool IsMap>
-    std::enable_if_t<IsUnordered>
-    testObservers();
+    void
+    testObservers()
+        requires IsUnordered;
 
     //--------------------------------------------------------------------------
 
@@ -616,8 +634,9 @@ public:
 // Check contents via at() and operator[]
 // map, unordered_map
 template <class Container, class Values>
-std::enable_if_t<Container::is_map::value && !Container::is_multi::value>
+void
 AgedAssociativeContainerTestBase::checkMapContents(Container& c, Values const& v)
+    requires(Container::is_map::value && !Container::is_multi::value)
 {
     if (v.empty())
     {
@@ -642,8 +661,9 @@ AgedAssociativeContainerTestBase::checkMapContents(Container& c, Values const& v
 
 // unordered
 template <class C, class Values>
-std::enable_if_t<std::remove_reference_t<C>::is_unordered::value>
+void
 AgedAssociativeContainerTestBase::checkUnorderedContentsRefRef(C&& c, Values const& v)
+    requires(std::remove_reference_t<C>::is_unordered::value)
 {
     using Cont = std::remove_reference_t<C>;
     using Traits =
@@ -715,8 +735,9 @@ AgedAssociativeContainerTestBase::checkContents(Cont& c)
 
 // ordered
 template <bool IsUnordered, bool IsMulti, bool IsMap>
-std::enable_if_t<!IsUnordered>
+void
 AgedAssociativeContainerTestBase::testConstructEmpty()
+    requires(!IsUnordered)
 {
     using Traits = TestTraits<IsUnordered, IsMulti, IsMap>;
     using Comp = Traits::Comp;
@@ -751,8 +772,9 @@ AgedAssociativeContainerTestBase::testConstructEmpty()
 
 // unordered
 template <bool IsUnordered, bool IsMulti, bool IsMap>
-std::enable_if_t<IsUnordered>
+void
 AgedAssociativeContainerTestBase::testConstructEmpty()
+    requires IsUnordered
 {
     using Traits = TestTraits<IsUnordered, IsMulti, IsMap>;
     using Hash = Traits::Hash;
@@ -809,8 +831,9 @@ AgedAssociativeContainerTestBase::testConstructEmpty()
 
 // ordered
 template <bool IsUnordered, bool IsMulti, bool IsMap>
-std::enable_if_t<!IsUnordered>
+void
 AgedAssociativeContainerTestBase::testConstructRange()
+    requires(!IsUnordered)
 {
     using Traits = TestTraits<IsUnordered, IsMulti, IsMap>;
     using Comp = Traits::Comp;
@@ -856,8 +879,9 @@ AgedAssociativeContainerTestBase::testConstructRange()
 
 // unordered
 template <bool IsUnordered, bool IsMulti, bool IsMap>
-std::enable_if_t<IsUnordered>
+void
 AgedAssociativeContainerTestBase::testConstructRange()
+    requires IsUnordered
 {
     using Traits = TestTraits<IsUnordered, IsMulti, IsMap>;
     using Hash = Traits::Hash;
@@ -922,8 +946,9 @@ AgedAssociativeContainerTestBase::testConstructRange()
 
 // ordered
 template <bool IsUnordered, bool IsMulti, bool IsMap>
-std::enable_if_t<!IsUnordered>
+void
 AgedAssociativeContainerTestBase::testConstructInitList()
+    requires(!IsUnordered)
 {
     using Traits = TestTraits<IsUnordered, IsMulti, IsMap>;
     typename Traits::ManualClock const clock;
@@ -938,8 +963,9 @@ AgedAssociativeContainerTestBase::testConstructInitList()
 
 // unordered
 template <bool IsUnordered, bool IsMulti, bool IsMap>
-std::enable_if_t<IsUnordered>
+void
 AgedAssociativeContainerTestBase::testConstructInitList()
+    requires IsUnordered
 {
     using Traits = TestTraits<IsUnordered, IsMulti, IsMap>;
     typename Traits::ManualClock const clock;
@@ -1084,8 +1110,9 @@ AgedAssociativeContainerTestBase::testIterator()
 }
 
 template <bool IsUnordered, bool IsMulti, bool IsMap>
-std::enable_if_t<!IsUnordered>
+void
 AgedAssociativeContainerTestBase::testReverseIterator()
+    requires(!IsUnordered)
 {
     using Traits = TestTraits<IsUnordered, IsMulti, IsMap>;
     typename Traits::ManualClock clock;
@@ -1348,8 +1375,9 @@ AgedAssociativeContainerTestBase::testChronological()
 
 // map, unordered_map
 template <bool IsUnordered, bool IsMulti, bool IsMap>
-std::enable_if_t<IsMap && !IsMulti>
+void
 AgedAssociativeContainerTestBase::testArrayCreate()
+    requires(IsMap && !IsMulti)
 {
     using Traits = TestTraits<IsUnordered, IsMulti, IsMap>;
     typename Traits::ManualClock clock;
@@ -1631,8 +1659,9 @@ AgedAssociativeContainerTestBase::testRangeErase()
 
 // ordered
 template <bool IsUnordered, bool IsMulti, bool IsMap>
-std::enable_if_t<!IsUnordered>
+void
 AgedAssociativeContainerTestBase::testCompare()
+    requires(!IsUnordered)
 {
     using Traits = TestTraits<IsUnordered, IsMulti, IsMap>;
     typename Traits::ManualClock clock;
@@ -1662,8 +1691,9 @@ AgedAssociativeContainerTestBase::testCompare()
 
 // ordered
 template <bool IsUnordered, bool IsMulti, bool IsMap>
-std::enable_if_t<!IsUnordered>
+void
 AgedAssociativeContainerTestBase::testObservers()
+    requires(!IsUnordered)
 {
     using Traits = TestTraits<IsUnordered, IsMulti, IsMap>;
     typename Traits::ManualClock clock;
@@ -1680,8 +1710,9 @@ AgedAssociativeContainerTestBase::testObservers()
 
 // unordered
 template <bool IsUnordered, bool IsMulti, bool IsMap>
-std::enable_if_t<IsUnordered>
+void
 AgedAssociativeContainerTestBase::testObservers()
+    requires IsUnordered
 {
     using Traits = TestTraits<IsUnordered, IsMulti, IsMap>;
     typename Traits::ManualClock clock;
diff --git a/src/test/core/Config_test.cpp b/src/test/core/Config_test.cpp
index fdac1e450d..38c14b8ac5 100644
--- a/src/test/core/Config_test.cpp
+++ b/src/test/core/Config_test.cpp
@@ -1136,7 +1136,7 @@ trust-these-validators.gov
     testZeroPort()
     {
         auto const contents = std::regex_replace(
-            detail::configContents("", ""), std::regex("port\\s*=\\s*\\d+"), "port = 0");
+            detail::configContents("", ""), std::regex(R"(port\s*=\s*\d+)"), "port = 0");
 
         try
         {
diff --git a/src/test/csf/Tx.h b/src/test/csf/Tx.h
index f871909f48..75254f865a 100644
--- a/src/test/csf/Tx.h
+++ b/src/test/csf/Tx.h
@@ -27,8 +27,10 @@ public:
     {
     }
 
-    template <typename T, typename = std::enable_if_t<std::is_same_v<T, Tx>>>
-    Tx(T const* t) : id_{t->id_}
+    template <typename T>
+    Tx(T const* t)
+        requires(std::is_same_v<T, Tx>)
+        : id_{t->id_}
     {
     }
 
diff --git a/src/test/csf/ledgers.h b/src/test/csf/ledgers.h
index dc5ec5277c..4873519dee 100644
--- a/src/test/csf/ledgers.h
+++ b/src/test/csf/ledgers.h
@@ -3,7 +3,6 @@
 #include <test/csf/Tx.h>
 
 #include <xrpl/basics/chrono.h>
-#include <xrpl/basics/comparators.h>
 #include <xrpl/basics/tagged_integer.h>
 #include <xrpl/json/json_value.h>
 #include <xrpl/ledger/LedgerTiming.h>
@@ -13,6 +12,7 @@
 #include <cassert>
 #include <cstddef>
 #include <cstdint>
+#include <functional>
 #include <optional>
 #include <set>
 #include <string>
@@ -232,8 +232,8 @@ private:
 class LedgerOracle
 {
     using InstanceMap = boost::bimaps::bimap<
-        boost::bimaps::set_of<Ledger::Instance, xrpl::less<Ledger::Instance>>,
-        boost::bimaps::set_of<Ledger::ID, xrpl::less<Ledger::ID>>>;
+        boost::bimaps::set_of<Ledger::Instance, std::less<>>,
+        boost::bimaps::set_of<Ledger::ID, std::less<>>>;
     using InstanceEntry = InstanceMap::value_type;
 
     // Set of all known ledgers; note this is never pruned
diff --git a/src/test/csf/submitters.h b/src/test/csf/submitters.h
index 546681abe0..a71c849fb7 100644
--- a/src/test/csf/submitters.h
+++ b/src/test/csf/submitters.h
@@ -61,8 +61,9 @@ class Submitter
     }
 
     template <class T>
-    static std::enable_if_t<std::is_arithmetic_v<T>, SimDuration>
+    static SimDuration
     asDuration(T t)
+        requires(std::is_arithmetic_v<T>)
     {
         return SimDuration{static_cast<SimDuration::rep>(t)};
     }
diff --git a/src/test/jtx/TestHelpers.h b/src/test/jtx/TestHelpers.h
index b1643de362..cb2193db99 100644
--- a/src/test/jtx/TestHelpers.h
+++ b/src/test/jtx/TestHelpers.h
@@ -401,8 +401,9 @@ void
 stpathAppendOne(STPath& st, Account const& account);
 
 template <class T>
-std::enable_if_t<std::is_constructible_v<Account, T>>
+void
 stpathAppendOne(STPath& st, T const& t)
+    requires(std::is_constructible_v<Account, T>)
 {
     stpathAppendOne(st, Account{t});
 }
diff --git a/src/test/jtx/TrustedPublisherServer.h b/src/test/jtx/TrustedPublisherServer.h
index 008bbe70c3..f5ee8aac3a 100644
--- a/src/test/jtx/TrustedPublisherServer.h
+++ b/src/test/jtx/TrustedPublisherServer.h
@@ -188,8 +188,8 @@ public:
 
             for (auto const& val : validators)
             {
-                data += "{\"validation_public_key\":\"" + strHex(val.masterPublic) +
-                    "\",\"manifest\":\"" + val.manifest + "\"},";
+                data += R"({"validation_public_key":")" + strHex(val.masterPublic) +
+                    R"(","manifest":")" + val.manifest + "\"},";
             }
             data.pop_back();
             data += "]}";
@@ -201,8 +201,8 @@ public:
         getList_ = [blob = blob, sig, manifest, version](int interval) {
             // Build the contents of a version 1 format UNL file
             std::stringstream l;
-            l << "{\"blob\":\"" << blob << "\"" << ",\"signature\":\"" << sig << "\""
-              << ",\"manifest\":\"" << manifest << "\""
+            l << R"({"blob":")" << blob << "\"" << R"(,"signature":")" << sig << "\""
+              << R"(,"manifest":")" << manifest << "\""
               << ",\"refresh_interval\": " << interval << ",\"version\":" << version << '}';
             return l.str();
         };
@@ -216,8 +216,8 @@ public:
             // Use the same set of validators for simplicity
             for (auto const& val : validators)
             {
-                data += "{\"validation_public_key\":\"" + strHex(val.masterPublic) +
-                    "\",\"manifest\":\"" + val.manifest + "\"},";
+                data += R"({"validation_public_key":")" + strHex(val.masterPublic) +
+                    R"(","manifest":")" + val.manifest + "\"},";
             }
             data.pop_back();
             data += "]}";
@@ -232,13 +232,13 @@ public:
             std::stringstream l;
             for (auto const& info : blobInfo)
             {
-                l << "{\"blob\":\"" << info.blob << "\"" << ",\"signature\":\"" << info.signature
+                l << R"({"blob":")" << info.blob << "\"" << R"(,"signature":")" << info.signature
                   << "\"},";
             }
             std::string blobs = l.str();
             blobs.pop_back();
             l.str(std::string());
-            l << "{\"blobs_v2\": [ " << blobs << "],\"manifest\":\"" << manifest << "\""
+            l << "{\"blobs_v2\": [ " << blobs << R"(],"manifest":")" << manifest << "\""
               << ",\"refresh_interval\": " << interval << ",\"version\":" << (version + 1) << '}';
             return l.str();
         };
diff --git a/src/test/jtx/amount.h b/src/test/jtx/amount.h
index ce0234b41a..db7dbd1cc1 100644
--- a/src/test/jtx/amount.h
+++ b/src/test/jtx/amount.h
@@ -93,19 +93,16 @@ public:
 
     /** drops */
     template <class T>
-    PrettyAmount(
-        T v,
-        std::enable_if_t<
-            sizeof(T) >= sizeof(int) && std::is_integral_v<T> && std::is_signed_v<T>>* = nullptr)
+    PrettyAmount(T v)
+        requires(sizeof(T) >= sizeof(int) && std::is_integral_v<T> && std::is_signed_v<T>)
         : amount_((v > 0) ? v : -v, v < 0)
     {
     }
 
     /** drops */
     template <class T>
-    PrettyAmount(
-        T v,
-        std::enable_if_t<sizeof(T) >= sizeof(int) && std::is_unsigned_v<T>>* = nullptr)
+    PrettyAmount(T v)
+        requires(sizeof(T) >= sizeof(int) && std::is_unsigned_v<T>)
         : amount_(v)
     {
     }
@@ -282,9 +279,10 @@ struct XrpT
         @param v The number of XRP (not drops)
     */
     /** @{ */
-    template <class T, class = std::enable_if_t<std::is_integral_v<T>>>
+    template <class T>
     PrettyAmount
     operator()(T v) const
+        requires(std::is_integral_v<T>)
     {
         using TOut = std::conditional_t<std::is_signed_v<T>, std::int64_t, std::uint64_t>;
         return {TOut{v} * kJtxDropsPerXrp};
@@ -350,9 +348,10 @@ extern XrpT const XRP;  // NOLINT(readability-identifier-naming)
     Example:
         drops(10)   Returns PrettyAmount of 10 drops
 */
-template <class Integer, class = std::enable_if_t<std::is_integral_v<Integer>>>
+template <class Integer>
 PrettyAmount
 drops(Integer i)
+    requires(std::is_integral_v<Integer>)
 {
     return {i};
 }
@@ -436,11 +435,10 @@ public:
         return asset();
     }
 
-    template <
-        class T,
-        class = std::enable_if_t<sizeof(T) >= sizeof(int) && std::is_arithmetic_v<T>>>
+    template <class T>
     PrettyAmount
     operator()(T v) const
+        requires(sizeof(T) >= sizeof(int) && std::is_arithmetic_v<T>)
     {
         // VFALCO NOTE Should throw if the
         //             representation of v is not exact.
diff --git a/src/test/jtx/impl/WSClient.cpp b/src/test/jtx/impl/WSClient.cpp
index c00a88f270..ca322415fb 100644
--- a/src/test/jtx/impl/WSClient.cpp
+++ b/src/test/jtx/impl/WSClient.cpp
@@ -30,6 +30,7 @@
 
 #include <chrono>
 #include <condition_variable>
+#include <cstddef>
 #include <exception>
 #include <functional>
 #include <iostream>
@@ -172,9 +173,9 @@ public:
                     }));
             ws_.handshake(ep.address().to_string() + ":" + std::to_string(ep.port()), "/");
             ws_.async_read(
-                rb_,
-                boost::asio::bind_executor(
-                    strand_, std::bind(&WSClientImpl::onReadMsg, this, std::placeholders::_1)));
+                rb_, boost::asio::bind_executor(strand_, [this](error_code const& ec, std::size_t) {
+                    onReadMsg(ec);
+                }));
         }
         catch (std::exception&)
         {
@@ -310,9 +311,9 @@ private:
             cv_.notify_all();
         }
         ws_.async_read(
-            rb_,
-            boost::asio::bind_executor(
-                strand_, std::bind(&WSClientImpl::onReadMsg, this, std::placeholders::_1)));
+            rb_, boost::asio::bind_executor(strand_, [this](error_code const& ec, std::size_t) {
+                onReadMsg(ec);
+            }));
     }
 
     // Called when the read op terminates
diff --git a/src/test/jtx/paths.h b/src/test/jtx/paths.h
index 1450985687..b141300a66 100644
--- a/src/test/jtx/paths.h
+++ b/src/test/jtx/paths.h
@@ -67,8 +67,9 @@ private:
     appendOne(AccountID const& account);
 
     template <class T>
-    std::enable_if_t<std::is_constructible_v<Account, T>>
+    void
     appendOne(T const& t)
+        requires(std::is_constructible_v<Account, T>)
     {
         appendOne(Account{t});
     }
diff --git a/src/test/nodestore/Basics_test.cpp b/src/test/nodestore/Basics_test.cpp
index 5565399cc2..7d77b18630 100644
--- a/src/test/nodestore/Basics_test.cpp
+++ b/src/test/nodestore/Basics_test.cpp
@@ -40,9 +40,9 @@ public:
 
         auto batch = createPredictableBatch(kNumObjectsToTest, seedValue);
 
-        for (int i = 0; i < batch.size(); ++i)
+        for (auto const& expected : batch)
         {
-            EncodedBlob const encoded(batch[i]);
+            EncodedBlob const encoded(expected);
 
             DecodedBlob decoded(encoded.getKey(), encoded.getData(), encoded.getSize());
 
@@ -52,7 +52,7 @@ public:
             {
                 std::shared_ptr<NodeObject> const object(decoded.createObject());
 
-                BEAST_EXPECT(isSame(batch[i], object));
+                BEAST_EXPECT(isSame(expected, object));
             }
         }
     }
diff --git a/src/test/nodestore/TestBase.h b/src/test/nodestore/TestBase.h
index 1254fc51aa..a1245ec963 100644
--- a/src/test/nodestore/TestBase.h
+++ b/src/test/nodestore/TestBase.h
@@ -124,9 +124,9 @@ public:
     static void
     storeBatch(Backend& backend, Batch const& batch)
     {
-        for (int i = 0; i < batch.size(); ++i)
+        for (auto const& object : batch)
         {
-            backend.store(batch[i]);
+            backend.store(object);
         }
     }
 
@@ -137,11 +137,11 @@ public:
         pCopy->clear();
         pCopy->reserve(batch.size());
 
-        for (int i = 0; i < batch.size(); ++i)
+        for (auto const& expected : batch)
         {
             std::shared_ptr<NodeObject> object;
 
-            Status const status = backend.fetch(batch[i]->getHash(), &object);
+            Status const status = backend.fetch(expected->getHash(), &object);
 
             BEAST_EXPECT(status == Status::Ok);
 
@@ -157,11 +157,11 @@ public:
     void
     fetchMissing(Backend& backend, Batch const& batch)
     {
-        for (int i = 0; i < batch.size(); ++i)
+        for (auto const& expected : batch)
         {
             std::shared_ptr<NodeObject> object;
 
-            Status const status = backend.fetch(batch[i]->getHash(), &object);
+            Status const status = backend.fetch(expected->getHash(), &object);
 
             BEAST_EXPECT(status == Status::NotFound);
         }
@@ -171,10 +171,8 @@ public:
     static void
     storeBatch(Database& db, Batch const& batch)
     {
-        for (int i = 0; i < batch.size(); ++i)
+        for (auto const& object : batch)
         {
-            std::shared_ptr<NodeObject> const object(batch[i]);
-
             Blob data(object->getData());
 
             db.store(object->getType(), std::move(data), object->getHash(), db.earliestLedgerSeq());
@@ -188,9 +186,9 @@ public:
         pCopy->clear();
         pCopy->reserve(batch.size());
 
-        for (int i = 0; i < batch.size(); ++i)
+        for (auto const& expected : batch)
         {
-            std::shared_ptr<NodeObject> const object = db.fetchNodeObject(batch[i]->getHash(), 0);
+            std::shared_ptr<NodeObject> const object = db.fetchNodeObject(expected->getHash(), 0);
 
             if (object != nullptr)
                 pCopy->push_back(object);
diff --git a/src/test/nodestore/Timing_test.cpp b/src/test/nodestore/Timing_test.cpp
index e308d0d5ff..1c296ca44c 100644
--- a/src/test/nodestore/Timing_test.cpp
+++ b/src/test/nodestore/Timing_test.cpp
@@ -564,10 +564,10 @@ public:
                     char p[2];
                     p[0] = rand_(gen_) < 50 ? 0 : 1;
                     p[1] = 1 - p[0];
-                    for (int q = 0; q < 2; ++q)
+                    for (char const op : p)
                     {
                         // NOLINTNEXTLINE(bugprone-switch-missing-default-case)
-                        switch (p[q])
+                        switch (op)
                         {
                             case 0: {
                                 // fetch recent
diff --git a/src/test/overlay/short_read_test.cpp b/src/test/overlay/short_read_test.cpp
index 9af632d65c..d856231b8d 100644
--- a/src/test/overlay/short_read_test.cpp
+++ b/src/test/overlay/short_read_test.cpp
@@ -26,7 +26,6 @@
 #include <chrono>
 #include <condition_variable>
 #include <cstddef>
-#include <functional>
 #include <map>
 #include <memory>
 #include <mutex>
@@ -199,7 +198,7 @@ private:
             {
                 if (!strand.running_in_this_thread())
                 {
-                    post(strand, std::bind(&Acceptor::close, shared_from_this()));
+                    post(strand, [self = shared_from_this()] { self->close(); });
                     return;
                 }
                 acceptor.close();
@@ -210,9 +209,9 @@ private:
             {
                 acceptor.async_accept(
                     socket,
-                    bind_executor(
-                        strand,
-                        std::bind(&Acceptor::onAccept, shared_from_this(), std::placeholders::_1)));
+                    bind_executor(strand, [self = shared_from_this()](error_code const& ec) {
+                        self->onAccept(ec);
+                    }));
             }
 
             void
@@ -239,9 +238,9 @@ private:
                 p->run();
                 acceptor.async_accept(
                     socket,
-                    bind_executor(
-                        strand,
-                        std::bind(&Acceptor::onAccept, shared_from_this(), std::placeholders::_1)));
+                    bind_executor(strand, [self = shared_from_this()](error_code const& ec) {
+                        self->onAccept(ec);
+                    }));
             }
         };
 
@@ -271,7 +270,7 @@ private:
             {
                 if (!strand.running_in_this_thread())
                 {
-                    post(strand, std::bind(&Connection::close, shared_from_this()));
+                    post(strand, [self = shared_from_this()] { self->close(); });
                     return;
                 }
                 if (socket.is_open())
@@ -287,13 +286,12 @@ private:
                 timer.expires_after(std::chrono::seconds(3));
                 timer.async_wait(bind_executor(
                     strand,
-                    std::bind(&Connection::onTimer, shared_from_this(), std::placeholders::_1)));
+                    [self = shared_from_this()](error_code const& ec) { self->onTimer(ec); }));
                 stream.async_handshake(
                     stream_type::server,
-                    bind_executor(
-                        strand,
-                        std::bind(
-                            &Connection::onHandshake, shared_from_this(), std::placeholders::_1)));
+                    bind_executor(strand, [self = shared_from_this()](error_code const& ec) {
+                        self->onHandshake(ec);
+                    }));
             }
 
             void
@@ -330,21 +328,16 @@ private:
                     fail("handshake", ec);
                     return;
                 }
-#if 1
                 boost::asio::async_read_until(
                     stream,
                     buf,
                     "\n",
                     bind_executor(
                         strand,
-                        std::bind(
-                            &Connection::onRead,
-                            shared_from_this(),
-                            std::placeholders::_1,
-                            std::placeholders::_2)));
-#else
-                close();
-#endif
+                        [self = shared_from_this()](
+                            error_code const& ec, std::size_t bytesTransferred) {
+                            self->onRead(ec, bytesTransferred);
+                        }));
             }
 
             void
@@ -353,10 +346,10 @@ private:
                 if (ec == boost::asio::error::eof)
                 {
                     server.test_.log << "[server] read: EOF" << std::endl;
-                    stream.async_shutdown(bind_executor(
-                        strand,
-                        std::bind(
-                            &Connection::onShutdown, shared_from_this(), std::placeholders::_1)));
+                    stream.async_shutdown(
+                        bind_executor(strand, [self = shared_from_this()](error_code const& ec) {
+                            self->onShutdown(ec);
+                        }));
                     return;
                 }
                 if (ec)
@@ -373,11 +366,10 @@ private:
                     buf.data(),
                     bind_executor(
                         strand,
-                        std::bind(
-                            &Connection::onWrite,
-                            shared_from_this(),
-                            std::placeholders::_1,
-                            std::placeholders::_2)));
+                        [self = shared_from_this()](
+                            error_code const& ec, std::size_t bytesTransferred) {
+                            self->onWrite(ec, bytesTransferred);
+                        }));
             }
 
             void
@@ -391,7 +383,7 @@ private:
                 }
                 stream.async_shutdown(bind_executor(
                     strand,
-                    std::bind(&Connection::onShutdown, shared_from_this(), std::placeholders::_1)));
+                    [self = shared_from_this()](error_code const& ec) { self->onShutdown(ec); }));
             }
 
             void
@@ -463,7 +455,7 @@ private:
             {
                 if (!strand.running_in_this_thread())
                 {
-                    post(strand, std::bind(&Connection::close, shared_from_this()));
+                    post(strand, [self = shared_from_this()] { self->close(); });
                     return;
                 }
                 if (socket.is_open())
@@ -479,13 +471,11 @@ private:
                 timer.expires_after(std::chrono::seconds(3));
                 timer.async_wait(bind_executor(
                     strand,
-                    std::bind(&Connection::onTimer, shared_from_this(), std::placeholders::_1)));
+                    [self = shared_from_this()](error_code const& ec) { self->onTimer(ec); }));
                 socket.async_connect(
-                    ep,
-                    bind_executor(
-                        strand,
-                        std::bind(
-                            &Connection::onConnect, shared_from_this(), std::placeholders::_1)));
+                    ep, bind_executor(strand, [self = shared_from_this()](error_code const& ec) {
+                        self->onConnect(ec);
+                    }));
             }
 
             void
@@ -524,10 +514,9 @@ private:
                 }
                 stream.async_handshake(
                     stream_type::client,
-                    bind_executor(
-                        strand,
-                        std::bind(
-                            &Connection::onHandshake, shared_from_this(), std::placeholders::_1)));
+                    bind_executor(strand, [self = shared_from_this()](error_code const& ec) {
+                        self->onHandshake(ec);
+                    }));
             }
 
             void
@@ -540,23 +529,15 @@ private:
                 }
                 write(buf, "HELLO\n");
 
-#if 1
                 boost::asio::async_write(
                     stream,
                     buf.data(),
                     bind_executor(
                         strand,
-                        std::bind(
-                            &Connection::onWrite,
-                            shared_from_this(),
-                            std::placeholders::_1,
-                            std::placeholders::_2)));
-#else
-                stream_.async_shutdown(bind_executor(
-                    strand_,
-                    std::bind(
-                        &Connection::on_shutdown, shared_from_this(), std::placeholders::_1)));
-#endif
+                        [self = shared_from_this()](
+                            error_code const& ec, std::size_t bytesTransferred) {
+                            self->onWrite(ec, bytesTransferred);
+                        }));
             }
 
             void
@@ -568,24 +549,16 @@ private:
                     fail("write", ec);
                     return;
                 }
-#if 1
                 boost::asio::async_read_until(
                     stream,
                     buf,
                     "\n",
                     bind_executor(
                         strand,
-                        std::bind(
-                            &Connection::onRead,
-                            shared_from_this(),
-                            std::placeholders::_1,
-                            std::placeholders::_2)));
-#else
-                stream_.async_shutdown(bind_executor(
-                    strand_,
-                    std::bind(
-                        &Connection::on_shutdown, shared_from_this(), std::placeholders::_1)));
-#endif
+                        [self = shared_from_this()](
+                            error_code const& ec, std::size_t bytesTransferred) {
+                            self->onRead(ec, bytesTransferred);
+                        }));
             }
 
             void
@@ -599,7 +572,7 @@ private:
                 buf.commit(bytesTransferred);
                 stream.async_shutdown(bind_executor(
                     strand,
-                    std::bind(&Connection::onShutdown, shared_from_this(), std::placeholders::_1)));
+                    [self = shared_from_this()](error_code const& ec) { self->onShutdown(ec); }));
             }
 
             void
diff --git a/src/test/protocol/Quality_test.cpp b/src/test/protocol/Quality_test.cpp
index db81886e94..e7ffa9f305 100644
--- a/src/test/protocol/Quality_test.cpp
+++ b/src/test/protocol/Quality_test.cpp
@@ -22,7 +22,8 @@ public:
 
     template <class Integer>
     static STAmount
-    amount(Integer integer, std::enable_if_t<std::is_signed_v<Integer>>* = 0)
+    amount(Integer integer)
+        requires(std::is_signed_v<Integer>)
     {
         static_assert(std::is_integral_v<Integer>);
         return STAmount(integer, false);
@@ -30,7 +31,8 @@ public:
 
     template <class Integer>
     static STAmount
-    amount(Integer integer, std::enable_if_t<!std::is_signed_v<Integer>>* = 0)
+    amount(Integer integer)
+        requires(!std::is_signed_v<Integer>)
     {
         static_assert(std::is_integral_v<Integer>);
         if (integer < 0)
diff --git a/src/test/protocol/TER_test.cpp b/src/test/protocol/TER_test.cpp
index af1cfced0e..77f12ff2b7 100644
--- a/src/test/protocol/TER_test.cpp
+++ b/src/test/protocol/TER_test.cpp
@@ -72,8 +72,9 @@ struct TER_test : public beast::unit_test::Suite
         std::size_t I2,
         template <std::size_t, std::size_t> class Func,
         typename Tup>
-    std::enable_if_t<I1 != 0>
+    void
     testIterate(Tup const& tup, beast::unit_test::Suite& s)
+        requires(I1 != 0)
     {
         Func<I1, I2> const func;
         func(tup, s);
@@ -86,8 +87,9 @@ struct TER_test : public beast::unit_test::Suite
         std::size_t I2,
         template <std::size_t, std::size_t> class Func,
         typename Tup>
-    std::enable_if_t<I1 == 0 && I2 != 0>
+    void
     testIterate(Tup const& tup, beast::unit_test::Suite& s)
+        requires(I1 == 0 && I2 != 0)
     {
         Func<I1, I2> const func;
         func(tup, s);
@@ -100,8 +102,9 @@ struct TER_test : public beast::unit_test::Suite
         std::size_t I2,
         template <std::size_t, std::size_t> class Func,
         typename Tup>
-    std::enable_if_t<I1 == 0 && I2 == 0>
+    void
     testIterate(Tup const& tup, beast::unit_test::Suite& s)
+        requires(I1 == 0 && I2 == 0)
     {
         Func<I1, I2> const func;
         func(tup, s);
diff --git a/src/test/resource/Logic_test.cpp b/src/test/resource/Logic_test.cpp
deleted file mode 100644
index de4575cb16..0000000000
--- a/src/test/resource/Logic_test.cpp
+++ /dev/null
@@ -1,294 +0,0 @@
-#include <test/unit_test/SuiteJournal.h>
-
-#include <xrpl/basics/Log.h>
-#include <xrpl/basics/chrono.h>
-#include <xrpl/basics/random.h>
-#include <xrpl/beast/insight/NullCollector.h>
-#include <xrpl/beast/net/IPAddressV4.h>
-#include <xrpl/beast/unit_test/suite.h>
-#include <xrpl/beast/utility/Journal.h>
-#include <xrpl/resource/Charge.h>
-#include <xrpl/resource/Consumer.h>
-#include <xrpl/resource/Disposition.h>
-#include <xrpl/resource/Gossip.h>
-#include <xrpl/resource/detail/Logic.h>
-#include <xrpl/resource/detail/Tuning.h>
-
-#include <boost/utility/base_from_member.hpp>
-
-#include <chrono>
-#include <cstdint>
-#include <functional>
-#include <string>
-
-namespace xrpl::Resource {
-
-class ResourceManager_test : public beast::unit_test::Suite
-{
-public:
-    class TestLogic : private boost::base_from_member<TestStopwatch>, public Logic
-
-    {
-    private:
-        using clock_type = boost::base_from_member<TestStopwatch>;
-
-    public:
-        explicit TestLogic(beast::Journal journal)
-            : Logic(beast::insight::NullCollector::make(), member, journal)
-        {
-        }
-
-        void
-        advance()
-        {
-            ++member;
-        }
-
-        TestStopwatch&
-        clock()
-        {
-            return member;
-        }
-    };
-
-    //--------------------------------------------------------------------------
-
-    static void
-    createGossip(Gossip& gossip)
-    {
-        std::uint8_t const v(10 + randInt(9));
-        std::uint8_t const n(10 + randInt(9));
-        gossip.items.reserve(n);
-        for (std::uint8_t i = 0; i < n; ++i)
-        {
-            Gossip::Item item;
-            item.balance = 100 + randInt(499);
-            beast::IP::AddressV4::bytes_type const d = {
-                {192, 0, 2, static_cast<std::uint8_t>(v + i)}};
-            item.address = beast::IP::Endpoint{beast::IP::AddressV4{d}};
-            gossip.items.push_back(item);
-        }
-    }
-
-    //--------------------------------------------------------------------------
-
-    void
-    testDrop(beast::Journal j, bool limited)
-    {
-        if (limited)
-        {
-            testcase("Limited warn/drop");
-        }
-        else
-        {
-            testcase("Unlimited warn/drop");
-        }
-
-        TestLogic logic(j);
-
-        Charge const fee(kDropThreshold + 1);
-        beast::IP::Endpoint const addr(beast::IP::Endpoint::fromString("192.0.2.2"));
-
-        std::function<Consumer(beast::IP::Endpoint)> const ep = limited
-            ? std::bind(&TestLogic::newInboundEndpoint, &logic, std::placeholders::_1)
-            : std::bind(&TestLogic::newUnlimitedEndpoint, &logic, std::placeholders::_1);
-
-        {
-            Consumer c(ep(addr));
-
-            // Create load until we get a warning
-            int n = 10000;
-
-            while (--n >= 0)
-            {
-                if (n == 0)
-                {
-                    if (limited)
-                    {
-                        fail("Loop count exceeded without warning");
-                    }
-                    else
-                    {
-                        pass();
-                    }
-                    return;
-                }
-
-                if (c.charge(fee) == Disposition::Warn)
-                {
-                    if (limited)
-                    {
-                        pass();
-                    }
-                    else
-                    {
-                        fail("Should loop forever with no warning");
-                    }
-                    break;
-                }
-                ++logic.clock();
-            }
-
-            // Create load until we get dropped
-            while (--n >= 0)
-            {
-                if (n == 0)
-                {
-                    if (limited)
-                    {
-                        fail("Loop count exceeded without dropping");
-                    }
-                    else
-                    {
-                        pass();
-                    }
-                    return;
-                }
-
-                if (c.charge(fee) == Disposition::Drop)
-                {
-                    // Disconnect abusive Consumer
-                    BEAST_EXPECT(c.disconnect(j) == limited);
-                    break;
-                }
-                ++logic.clock();
-            }
-        }
-
-        // Make sure the consumer is on the blacklist for a while.
-        {
-            Consumer const c(logic.newInboundEndpoint(addr));
-            logic.periodicActivity();
-            if (c.disposition() != Disposition::Drop)
-            {
-                if (limited)
-                {
-                    fail("Dropped consumer not put on blacklist");
-                }
-                else
-                {
-                    pass();
-                }
-                return;
-            }
-        }
-
-        // Makes sure the Consumer is eventually removed from blacklist
-        bool readmitted = false;
-        {
-            using namespace std::chrono_literals;
-            // Give Consumer time to become readmitted.  Should never
-            // exceed expiration time.
-            auto n = kSecondsUntilExpiration + 1s;
-            while (--n > 0s)
-            {
-                ++logic.clock();
-                logic.periodicActivity();
-                Consumer const c(logic.newInboundEndpoint(addr));
-                if (c.disposition() != Disposition::Drop)
-                {
-                    readmitted = true;
-                    break;
-                }
-            }
-        }
-        if (!readmitted)
-        {
-            fail("Dropped Consumer left on blacklist too long");
-            return;
-        }
-        pass();
-    }
-
-    void
-    testImports(beast::Journal j)
-    {
-        testcase("Imports");
-
-        TestLogic logic(j);
-
-        Gossip g[5];
-
-        for (int i = 0; i < 5; ++i)
-            createGossip(g[i]);
-
-        for (int i = 0; i < 5; ++i)
-            logic.importConsumers(std::to_string(i), g[i]);
-
-        pass();
-    }
-
-    void
-    testImport(beast::Journal j)
-    {
-        testcase("Import");
-
-        TestLogic logic(j);
-
-        Gossip g;
-        Gossip::Item item;
-        item.balance = 100;
-        beast::IP::AddressV4::bytes_type const d = {{192, 0, 2, 1}};
-        item.address = beast::IP::Endpoint{beast::IP::AddressV4{d}};
-        g.items.push_back(item);
-
-        logic.importConsumers("g", g);
-
-        pass();
-    }
-
-    void
-    testCharges(beast::Journal j)
-    {
-        testcase("Charge");
-
-        TestLogic logic(j);
-
-        {
-            beast::IP::Endpoint const address(beast::IP::Endpoint::fromString("192.0.2.1"));
-            Consumer c(logic.newInboundEndpoint(address));
-            Charge const fee(1000);
-            JLOG(j.info()) << "Charging " << c.toString() << " " << fee << " per second";
-            c.charge(fee);
-            for (int i = 0; i < 128; ++i)
-            {
-                JLOG(j.info()) << "Time= " << logic.clock().now().time_since_epoch().count()
-                               << ", Balance = " << c.balance();
-                logic.advance();
-            }
-        }
-
-        {
-            beast::IP::Endpoint const address(beast::IP::Endpoint::fromString("192.0.2.2"));
-            Consumer c(logic.newInboundEndpoint(address));
-            Charge const fee(1000);
-            JLOG(j.info()) << "Charging " << c.toString() << " " << fee << " per second";
-            for (int i = 0; i < 128; ++i)
-            {
-                c.charge(fee);
-                JLOG(j.info()) << "Time= " << logic.clock().now().time_since_epoch().count()
-                               << ", Balance = " << c.balance();
-                logic.advance();
-            }
-        }
-
-        pass();
-    }
-
-    void
-    run() override
-    {
-        using beast::Severity;
-        test::SuiteJournal journal("ResourceManager_test", *this);
-
-        testDrop(journal, true);
-        testDrop(journal, false);
-        testCharges(journal);
-        testImports(journal);
-        testImport(journal);
-    }
-};
-
-BEAST_DEFINE_TESTSUITE(ResourceManager, resource, xrpl);
-
-}  // namespace xrpl::Resource
diff --git a/src/test/rpc/AccountInfo_test.cpp b/src/test/rpc/AccountInfo_test.cpp
index d061be1f0e..61a11d0b93 100644
--- a/src/test/rpc/AccountInfo_test.cpp
+++ b/src/test/rpc/AccountInfo_test.cpp
@@ -234,7 +234,7 @@ public:
         withSigners[jss::account] = alice.human();
         withSigners[jss::signer_lists] = true;
 
-        auto const withSignersAsString = std::string("{ ") + "\"api_version\": 2, \"account\": \"" +
+        auto const withSignersAsString = std::string("{ ") + R"("api_version": 2, "account": ")" +
             alice.human() + "\", " + "\"signer_lists\": asdfggh }";
 
         // Alice has no SignerList yet.
diff --git a/src/test/rpc/AccountTx_test.cpp b/src/test/rpc/AccountTx_test.cpp
index bd7b07e936..ace8743e1e 100644
--- a/src/test/rpc/AccountTx_test.cpp
+++ b/src/test/rpc/AccountTx_test.cpp
@@ -41,7 +41,6 @@
 #include <chrono>
 #include <cstddef>
 #include <cstdint>
-#include <functional>
 #include <initializer_list>
 #include <iterator>
 #include <memory>
@@ -893,7 +892,7 @@ public:
     void
     run() override
     {
-        forAllApiVersions(std::bind_front(&AccountTx_test::testParameters, this));
+        forAllApiVersions([this](unsigned apiVersion) { testParameters(apiVersion); });
         testContents();
         testAccountDelete();
         testMPT();
diff --git a/src/test/rpc/GetAggregatePrice_test.cpp b/src/test/rpc/GetAggregatePrice_test.cpp
index 214bd12183..3e0bfa1fd3 100644
--- a/src/test/rpc/GetAggregatePrice_test.cpp
+++ b/src/test/rpc/GetAggregatePrice_test.cpp
@@ -7,6 +7,7 @@
 
 #include <xrpl/basics/Number.h>
 #include <xrpl/basics/base_uint.h>
+#include <xrpl/basics/random.h>
 #include <xrpl/beast/unit_test/suite.h>
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/core/ServiceRegistry.h>
@@ -16,7 +17,7 @@
 #include <xrpl/protocol/SField.h>
 #include <xrpl/protocol/jss.h>
 
-#include <cstdlib>
+#include <cstdint>
 #include <memory>
 #include <optional>
 #include <string>
@@ -173,7 +174,7 @@ public:
                 Oracle const oracle(
                     env,
                     {.owner = owner,
-                     .documentID = rand(),
+                     .documentID = randInt<std::uint32_t>(),
                      .series = {{"XRP", "USD", 740 + i, 1}, {"XRP", "EUR", 740, 1}},
                      .fee = baseFee});
                 oracles.emplace_back(owner, oracle.documentID());
@@ -297,13 +298,13 @@ public:
 
             OraclesData oracles;
             prep(env, oracles);
-            for (int i = 0; i < oracles.size(); ++i)
+            for (auto& oracleData : oracles)
             {
                 Oracle oracle(
                     env,
-                    {.owner = oracles[i].first,
+                    {.owner = oracleData.first,
                      // NOLINTNEXTLINE(bugprone-unchecked-optional-access)
-                     .documentID = asUInt(*oracles[i].second),
+                     .documentID = asUInt(*oracleData.second),
                      .fee = baseFee},
                     false);
                 // push XRP/USD by two ledgers, so this price
diff --git a/src/test/rpc/JSONRPC_test.cpp b/src/test/rpc/JSONRPC_test.cpp
index 7f6b123533..e18974e7e7 100644
--- a/src/test/rpc/JSONRPC_test.cpp
+++ b/src/test/rpc/JSONRPC_test.cpp
@@ -2238,7 +2238,7 @@ public:
 
         {
             json::Value req;
-            json::Reader().parse("{ \"fee_mult_max\" : 1, \"tx_json\" : { } } ", req);
+            json::Reader().parse(R"({ "fee_mult_max" : 1, "tx_json" : { } } )", req);
             json::Value const result = checkFee(
                 req,
                 Role::ADMIN,
@@ -2275,7 +2275,7 @@ public:
 
         {
             json::Value req;
-            json::Reader().parse("{ \"fee_mult_max\" : 0, \"tx_json\" : { } } ", req);
+            json::Reader().parse(R"({ "fee_mult_max" : 0, "tx_json" : { } } )", req);
             json::Value const result = checkFee(
                 req,
                 Role::ADMIN,
diff --git a/src/test/rpc/LedgerEntry_test.cpp b/src/test/rpc/LedgerEntry_test.cpp
index 59dbf618f0..c7ef5cef2d 100644
--- a/src/test/rpc/LedgerEntry_test.cpp
+++ b/src/test/rpc/LedgerEntry_test.cpp
@@ -2917,29 +2917,32 @@ class LedgerEntry_XChain_test : public beast::unit_test::Suite,
             BEAST_EXPECT(
                 attest[json::Value::UInt(0)].isMember(sfXChainCreateAccountProofSig.jsonName));
             json::Value a[kNumAttest];
-            for (size_t i = 0; i < kNumAttest; ++i)
+            for (auto& attestation : a)
             {
-                a[i] = attest[json::Value::UInt(0)][sfXChainCreateAccountProofSig.jsonName];
+                attestation = attest[json::Value::UInt(0)][sfXChainCreateAccountProofSig.jsonName];
                 BEAST_EXPECT(
-                    a[i].isMember(jss::Amount) && a[i][jss::Amount].asInt() == 1000 * kDropPerXrp);
+                    attestation.isMember(jss::Amount) &&
+                    attestation[jss::Amount].asInt() == 1000 * kDropPerXrp);
                 BEAST_EXPECT(
-                    a[i].isMember(jss::Destination) && a[i][jss::Destination] == scCarol.human());
+                    attestation.isMember(jss::Destination) &&
+                    attestation[jss::Destination] == scCarol.human());
                 BEAST_EXPECT(
-                    a[i].isMember(sfAttestationSignerAccount.jsonName) &&
+                    attestation.isMember(sfAttestationSignerAccount.jsonName) &&
                     std::ranges::any_of(signers, [&](Signer const& s) {
-                        return a[i][sfAttestationSignerAccount.jsonName] == s.account.human();
+                        return attestation[sfAttestationSignerAccount.jsonName] ==
+                            s.account.human();
                     }));
                 BEAST_EXPECT(
-                    a[i].isMember(sfAttestationRewardAccount.jsonName) &&
+                    attestation.isMember(sfAttestationRewardAccount.jsonName) &&
                     std::ranges::any_of(payee, [&](Account const& account) {
-                        return a[i][sfAttestationRewardAccount.jsonName] == account.human();
+                        return attestation[sfAttestationRewardAccount.jsonName] == account.human();
                     }));
                 BEAST_EXPECT(
-                    a[i].isMember(sfWasLockingChainSend.jsonName) &&
-                    a[i][sfWasLockingChainSend.jsonName] == 1);
+                    attestation.isMember(sfWasLockingChainSend.jsonName) &&
+                    attestation[sfWasLockingChainSend.jsonName] == 1);
                 BEAST_EXPECT(
-                    a[i].isMember(sfSignatureReward.jsonName) &&
-                    a[i][sfSignatureReward.jsonName].asInt() == 1 * kDropPerXrp);
+                    attestation.isMember(sfSignatureReward.jsonName) &&
+                    attestation[sfSignatureReward.jsonName].asInt() == 1 * kDropPerXrp);
             }
         }
 
diff --git a/src/test/rpc/LedgerRequest_test.cpp b/src/test/rpc/LedgerRequest_test.cpp
index 4759256b96..93feee9497 100644
--- a/src/test/rpc/LedgerRequest_test.cpp
+++ b/src/test/rpc/LedgerRequest_test.cpp
@@ -11,7 +11,6 @@
 #include <xrpl/protocol/ErrorCodes.h>
 #include <xrpl/protocol/jss.h>
 
-#include <functional>
 #include <memory>
 #include <string>
 #include <utility>
@@ -350,7 +349,7 @@ public:
     {
         testLedgerRequest();
         testEvolution();
-        forAllApiVersions(std::bind_front(&LedgerRequest_test::testBadInput, this));
+        forAllApiVersions([this](unsigned apiVersion) { testBadInput(apiVersion); });
         testMoreThan256Closed();
         testNonAdmin();
     }
diff --git a/src/test/rpc/RPCCall_test.cpp b/src/test/rpc/RPCCall_test.cpp
index cd3cd3cb41..4b5ab1f230 100644
--- a/src/test/rpc/RPCCall_test.cpp
+++ b/src/test/rpc/RPCCall_test.cpp
@@ -14,7 +14,6 @@
 
 #include <cstdint>
 #include <cstring>
-#include <functional>
 #include <initializer_list>
 #include <memory>
 #include <string>
@@ -5927,7 +5926,7 @@ public:
     void
     run() override
     {
-        forAllApiVersions(std::bind_front(&RPCCall_test::testRPCCall, this));
+        forAllApiVersions([this](unsigned apiVersion) { testRPCCall(apiVersion); });
     }
 };
 
diff --git a/src/test/rpc/ServerDefinitions_test.cpp b/src/test/rpc/ServerDefinitions_test.cpp
index bac1b4f7a5..bf345e6fdf 100644
--- a/src/test/rpc/ServerDefinitions_test.cpp
+++ b/src/test/rpc/ServerDefinitions_test.cpp
@@ -433,7 +433,7 @@ public:
                 Env env(*this);
                 auto const firstResult = env.rpc("server_definitions");
                 auto const hash = firstResult[jss::result][jss::hash].asString();
-                auto const hashParam = std::string("{ ") + "\"hash\": \"" + hash + "\"}";
+                auto const hashParam = std::string("{ ") + R"("hash": ")" + hash + "\"}";
 
                 auto const result = env.rpc("json", "server_definitions", hashParam);
                 BEAST_EXPECT(!result[jss::result].isMember(jss::error));
@@ -456,7 +456,7 @@ public:
                 std::string const hash =
                     "54296160385A27154BFA70A239DD8E8FD4CC2DB7BA32D970BA3A5B132CF749"
                     "D1";
-                auto const hashParam = std::string("{ ") + "\"hash\": \"" + hash + "\"}";
+                auto const hashParam = std::string("{ ") + R"("hash": ")" + hash + "\"}";
 
                 auto const result = env.rpc("json", "server_definitions", hashParam);
                 BEAST_EXPECT(!result[jss::result].isMember(jss::error));
diff --git a/src/test/rpc/TransactionEntry_test.cpp b/src/test/rpc/TransactionEntry_test.cpp
index 8724e2974d..38a95e84f8 100644
--- a/src/test/rpc/TransactionEntry_test.cpp
+++ b/src/test/rpc/TransactionEntry_test.cpp
@@ -17,7 +17,6 @@
 #include <xrpl/protocol/ErrorCodes.h>
 #include <xrpl/protocol/jss.h>
 
-#include <functional>
 #include <memory>
 #include <stdexcept>
 #include <string>
@@ -353,7 +352,7 @@ public:
     run() override
     {
         testBadInput();
-        forAllApiVersions(std::bind_front(&TransactionEntry_test::testRequest, this));
+        forAllApiVersions([this](unsigned apiVersion) { testRequest(apiVersion); });
     }
 };
 
diff --git a/src/test/rpc/Transaction_test.cpp b/src/test/rpc/Transaction_test.cpp
index 8c50736b85..c3bf707ec4 100644
--- a/src/test/rpc/Transaction_test.cpp
+++ b/src/test/rpc/Transaction_test.cpp
@@ -31,7 +31,6 @@
 #include <cctype>
 #include <cstddef>
 #include <cstdint>
-#include <functional>
 #include <memory>
 #include <optional>
 #include <string>
@@ -886,7 +885,7 @@ public:
     run() override
     {
         using namespace test::jtx;
-        forAllApiVersions(std::bind_front(&Transaction_test::testBinaryRequest, this));
+        forAllApiVersions([this](unsigned apiVersion) { testBinaryRequest(apiVersion); });
 
         FeatureBitset const all{testableAmendments()};
         testWithFeats(all);
@@ -899,7 +898,8 @@ public:
         testRangeCTIDRequest(features);
         testCTIDValidation(features);
         testRPCsForCTID(features);
-        forAllApiVersions(std::bind_front(&Transaction_test::testRequest, this, features));
+        forAllApiVersions(
+            [this, features](unsigned apiVersion) { testRequest(features, apiVersion); });
     }
 };
 
diff --git a/src/test/rpc/Version_test.cpp b/src/test/rpc/Version_test.cpp
index 20740bfe53..71830c2219 100644
--- a/src/test/rpc/Version_test.cpp
+++ b/src/test/rpc/Version_test.cpp
@@ -76,7 +76,7 @@ class Version_test : public beast::unit_test::Suite
                 "}");
         BEAST_EXPECT(badVersion(re));
 
-        re = env.rpc("json", "version", "{\"api_version\": \"a\"}");
+        re = env.rpc("json", "version", R"({"api_version": "a"})");
         BEAST_EXPECT(badVersion(re));
     }
 
diff --git a/src/test/shamap/FetchPack_test.cpp b/src/test/shamap/FetchPack_test.cpp
deleted file mode 100644
index bcc5129f01..0000000000
--- a/src/test/shamap/FetchPack_test.cpp
+++ /dev/null
@@ -1,169 +0,0 @@
-#include <test/shamap/common.h>
-#include <test/unit_test/SuiteJournal.h>
-
-#include <xrpl/basics/Blob.h>
-#include <xrpl/basics/Log.h>
-#include <xrpl/basics/SHAMapHash.h>
-#include <xrpl/basics/Slice.h>
-#include <xrpl/basics/UnorderedContainers.h>
-#include <xrpl/basics/contract.h>
-#include <xrpl/basics/random.h>
-#include <xrpl/beast/unit_test/suite.h>
-#include <xrpl/beast/utility/Journal.h>
-#include <xrpl/beast/xor_shift_engine.h>
-#include <xrpl/protocol/Serializer.h>
-#include <xrpl/protocol/digest.h>
-#include <xrpl/shamap/SHAMap.h>
-#include <xrpl/shamap/SHAMapItem.h>
-#include <xrpl/shamap/SHAMapMissingNode.h>
-#include <xrpl/shamap/SHAMapSyncFilter.h>
-#include <xrpl/shamap/SHAMapTreeNode.h>
-
-#include <boost/smart_ptr/intrusive_ptr.hpp>
-
-#include <cassert>
-#include <cstddef>
-#include <cstdint>
-#include <memory>
-#include <optional>
-#include <stdexcept>
-
-namespace xrpl::tests {
-
-class FetchPack_test : public beast::unit_test::Suite
-{
-public:
-    static constexpr auto kTableItems = 100;
-    static constexpr auto kTableItemsExtra = 20;
-
-    using Map = hash_map<SHAMapHash, Blob>;
-    using Table = SHAMap;
-    using Item = SHAMapItem;
-
-    struct Handler
-    {
-        void
-        operator()(std::uint32_t refNum) const
-        {
-            Throw<std::runtime_error>("missing node");
-        }
-    };
-
-    struct TestFilter : SHAMapSyncFilter
-    {
-        TestFilter(Map& map, beast::Journal journal) : map(map), journal(journal)
-        {
-        }
-
-        void
-        gotNode(
-            bool fromFilter,
-            SHAMapHash const& nodeHash,
-            std::uint32_t ledgerSeq,
-            Blob&& nodeData,  // NOLINT(cppcoreguidelines-rvalue-reference-param-not-moved)
-            SHAMapNodeType type) const override
-        {
-        }
-
-        [[nodiscard]] std::optional<Blob>
-        getNode(SHAMapHash const& nodeHash) const override
-        {
-            auto const it = map.find(nodeHash);
-            if (it == map.end())
-            {
-                JLOG(journal.fatal()) << "Test filter missing node";
-                return std::nullopt;
-            }
-            return it->second;
-        }
-
-        Map& map;
-        beast::Journal journal;
-    };
-
-    static boost::intrusive_ptr<Item>
-    makeRandomItemMember(beast::xor_shift_engine& r)
-    {
-        Serializer s;
-        for (int d = 0; d < 3; ++d)
-            s.add32(xrpl::randInt<std::uint32_t>(r));
-        return makeShamapitem(s.getSHA512Half(), s.slice());
-    }
-
-    static void
-    addRandomItems(std::size_t n, Table& t, beast::xor_shift_engine& r)
-    {
-        while ((n--) != 0u)
-        {
-            auto const result(t.addItem(SHAMapNodeType::TnAccountState, makeRandomItemMember(r)));
-            assert(result);
-            (void)result;
-        }
-    }
-
-    void
-    onFetch(Map& map, SHAMapHash const& hash, Blob const& blob)
-    {
-        BEAST_EXPECT(sha512Half(makeSlice(blob)) == hash.asUInt256());
-        map.emplace(hash, blob);
-    }
-
-    void
-    run() override
-    {
-        using beast::Severity;
-        test::SuiteJournal journal("FetchPack_test", *this);
-
-        TestNodeFamily f(journal);
-        std::shared_ptr<Table> const t1(std::make_shared<Table>(SHAMapType::FREE, f));
-
-        pass();
-
-        //         beast::Random r;
-        //         add_random_items_ (tableItems, *t1, r);
-        //         std::shared_ptr <Table> t2 (t1->snapShot (true));
-        //
-        //         add_random_items_ (tableItemsExtra, *t1, r);
-        //         add_random_items_ (tableItemsExtra, *t2, r);
-
-        // turn t1 into t2
-        //         Map map;
-        //         t2->getFetchPack (t1.get(), true, 1000000, std::bind (
-        //             &FetchPack_test::on_fetch, this, std::ref (map),
-        //             std::placeholders::_1, std::placeholders::_2));
-        //         t1->getFetchPack (nullptr, true, 1000000, std::bind (
-        //             &FetchPack_test::on_fetch, this, std::ref (map),
-        //             std::placeholders::_1, std::placeholders::_2));
-
-        // try to rebuild t2 from the fetch pack
-        //         std::shared_ptr <Table> t3;
-        //         try
-        //         {
-        //             TestFilter filter (map, beast::Journal());
-        //
-        //             t3 = std::make_shared <Table> (SHAMapType::FREE,
-        //             t2->getHash (),
-        //                 fullBelowCache);
-        //
-        //             BEAST_EXPECT(t3->fetchRoot (t2->getHash (), &filter),
-        //             "unable to get root");
-        //
-        //             // everything should be in the pack, no hashes should be
-        //             needed std::vector <uint256> hashes =
-        //             t3->getNeededHashes(1, &filter);
-        //             BEAST_EXPECT(hashes.empty(), "missing hashes");
-        //
-        //             BEAST_EXPECT(t3->getHash () == t2->getHash (), "root
-        //             hashes do not match"); BEAST_EXPECT(t3->deepCompare
-        //             (*t2), "failed compare");
-        //         }
-        //         catch (std::exception const&)
-        //         {
-        //             fail ("unhandled exception");
-        //         }
-    }
-};
-
-BEAST_DEFINE_TESTSUITE(FetchPack, shamap, xrpl);
-
-}  // namespace xrpl::tests
diff --git a/src/test/shamap/SHAMapSync_test.cpp b/src/test/shamap/SHAMapSync_test.cpp
deleted file mode 100644
index 9e9a490977..0000000000
--- a/src/test/shamap/SHAMapSync_test.cpp
+++ /dev/null
@@ -1,178 +0,0 @@
-#include <test/shamap/common.h>
-#include <test/unit_test/SuiteJournal.h>
-
-#include <xrpl/basics/Blob.h>
-#include <xrpl/basics/SHAMapHash.h>
-#include <xrpl/basics/Slice.h>
-#include <xrpl/basics/base_uint.h>
-#include <xrpl/basics/random.h>
-#include <xrpl/beast/unit_test/suite.h>
-#include <xrpl/beast/utility/Journal.h>
-#include <xrpl/beast/xor_shift_engine.h>
-#include <xrpl/protocol/Serializer.h>
-#include <xrpl/shamap/SHAMap.h>
-#include <xrpl/shamap/SHAMapItem.h>
-#include <xrpl/shamap/SHAMapMissingNode.h>
-#include <xrpl/shamap/SHAMapTreeNode.h>
-
-#include <boost/smart_ptr/intrusive_ptr.hpp>
-
-#include <chrono>
-#include <cstddef>
-#include <cstdint>
-#include <list>
-#include <ostream>
-#include <utility>
-#include <vector>
-
-namespace xrpl::tests {
-
-class SHAMapSync_test : public beast::unit_test::Suite
-{
-public:
-    beast::xor_shift_engine eng;
-
-    boost::intrusive_ptr<SHAMapItem>
-    makeRandomAS()
-    {
-        Serializer s;
-
-        for (int d = 0; d < 3; ++d)
-            s.add32(randInt<std::uint32_t>(eng));
-        return makeShamapitem(s.getSHA512Half(), s.slice());
-    }
-
-    bool
-    confuseMap(SHAMap& map, int count)
-    {
-        // add a bunch of random states to a map, then remove them
-        // map should be the same
-        SHAMapHash const beforeHash = map.getHash();
-
-        std::list<uint256> items;
-
-        for (int i = 0; i < count; ++i)
-        {
-            auto item = makeRandomAS();
-            items.push_back(item->key());
-
-            if (!map.addItem(SHAMapNodeType::TnAccountState, item))
-            {
-                log << "Unable to add item to map\n";
-                return false;
-            }
-        }
-
-        for (auto const& item : items)
-        {
-            if (!map.delItem(item))
-            {
-                log << "Unable to remove item from map\n";
-                return false;
-            }
-        }
-
-        if (beforeHash != map.getHash())
-        {
-            log << "Hashes do not match " << beforeHash << " " << map.getHash() << std::endl;
-            return false;
-        }
-
-        return true;
-    }
-
-    void
-    run() override
-    {
-        using beast::Severity;
-        test::SuiteJournal journal("SHAMapSync_test", *this);
-
-        TestNodeFamily f(journal), f2(journal);
-        SHAMap source(SHAMapType::FREE, f);
-        SHAMap destination(SHAMapType::FREE, f2);
-
-        int const items = 10000;
-        for (int i = 0; i < items; ++i)
-        {
-            source.addItem(SHAMapNodeType::TnAccountState, makeRandomAS());
-            if (i % 100 == 0)
-                source.invariants();
-        }
-
-        source.invariants();
-        BEAST_EXPECT(confuseMap(source, 500));
-        source.invariants();
-
-        source.setImmutable();
-
-        int count = 0;
-        source.visitLeaves([&count](auto const& item) { ++count; });
-        BEAST_EXPECT(count == items);
-
-        std::vector<SHAMapMissingNode> missingNodes;
-        source.walkMap(missingNodes, 2048);
-        BEAST_EXPECT(missingNodes.empty());
-
-        destination.setSynching();
-
-        {
-            std::vector<std::pair<SHAMapNodeID, Blob>> a;
-
-            BEAST_EXPECT(source.getNodeFat(SHAMapNodeID(), a, randBool(eng), randInt(eng, 2)));
-
-            unexpected(a.empty(), "NodeSize");
-
-            BEAST_EXPECT(destination.addRootNode(source.getHash(), makeSlice(a[0].second), nullptr)
-                             .isGood());
-        }
-
-        do
-        {
-            f.clock().advance(std::chrono::seconds(1));
-
-            // get the list of nodes we know we need
-            auto nodesMissing = destination.getMissingNodes(2048, nullptr);
-
-            if (nodesMissing.empty())
-                break;
-
-            // get as many nodes as possible based on this information
-            std::vector<std::pair<SHAMapNodeID, Blob>> b;
-
-            for (auto& it : nodesMissing)
-            {
-                // Don't use BEAST_EXPECT here b/c it will be called a
-                // non-deterministic number of times and the number of tests run
-                // should be deterministic
-                if (!source.getNodeFat(it.first, b, randBool(eng), randInt(eng, 2)))
-                    fail("", __FILE__, __LINE__);
-            }
-
-            // Don't use BEAST_EXPECT here b/c it will be called a
-            // non-deterministic number of times and the number of tests run
-            // should be deterministic
-            if (b.empty())
-                fail("", __FILE__, __LINE__);
-
-            for (std::size_t i = 0; i < b.size(); ++i)
-            {
-                // Don't use BEAST_EXPECT here b/c it will be called a
-                // non-deterministic number of times and the number of tests run
-                // should be deterministic
-                if (!destination.addKnownNode(b[i].first, makeSlice(b[i].second), nullptr)
-                         .isUseful())
-                    fail("", __FILE__, __LINE__);
-            }
-        } while (true);
-
-        destination.clearSynching();
-
-        BEAST_EXPECT(source.deepCompare(destination));
-
-        destination.invariants();
-    }
-};
-
-BEAST_DEFINE_TESTSUITE(SHAMapSync, shamap, xrpl);
-
-}  // namespace xrpl::tests
diff --git a/src/test/shamap/SHAMap_test.cpp b/src/test/shamap/SHAMap_test.cpp
deleted file mode 100644
index 5ff5ef5e05..0000000000
--- a/src/test/shamap/SHAMap_test.cpp
+++ /dev/null
@@ -1,427 +0,0 @@
-#include <test/shamap/common.h>
-#include <test/unit_test/SuiteJournal.h>
-
-#include <xrpl/basics/Blob.h>
-#include <xrpl/basics/Buffer.h>
-#include <xrpl/basics/SHAMapHash.h>
-#include <xrpl/basics/base_uint.h>
-#include <xrpl/beast/unit_test/suite.h>
-#include <xrpl/beast/utility/Journal.h>
-#include <xrpl/beast/utility/Zero.h>
-#include <xrpl/shamap/SHAMap.h>
-#include <xrpl/shamap/SHAMapInnerNode.h>
-#include <xrpl/shamap/SHAMapItem.h>
-#include <xrpl/shamap/SHAMapLeafNode.h>
-#include <xrpl/shamap/SHAMapMissingNode.h>
-#include <xrpl/shamap/SHAMapTreeNode.h>
-
-#include <algorithm>
-#include <array>
-#include <cstdint>
-#include <memory>
-#include <type_traits>
-#include <utility>
-#include <vector>
-
-namespace xrpl::tests {
-
-#ifndef __INTELLISENSE__
-static_assert(std::is_nothrow_destructible<SHAMap>{});
-static_assert(!std::is_default_constructible<SHAMap>{});
-static_assert(!std::is_copy_constructible<SHAMap>{});
-static_assert(!std::is_copy_assignable<SHAMap>{});
-static_assert(!std::is_move_constructible<SHAMap>{});
-static_assert(!std::is_move_assignable<SHAMap>{});
-
-static_assert(std::is_nothrow_destructible<SHAMap::ConstIterator>{});
-static_assert(std::is_copy_constructible<SHAMap::ConstIterator>{});
-static_assert(std::is_copy_assignable<SHAMap::ConstIterator>{});
-static_assert(std::is_move_constructible<SHAMap::ConstIterator>{});
-static_assert(std::is_move_assignable<SHAMap::ConstIterator>{});
-
-static_assert(std::is_nothrow_destructible<SHAMapItem>{});
-static_assert(!std::is_default_constructible<SHAMapItem>{});
-static_assert(!std::is_copy_constructible<SHAMapItem>{});
-
-static_assert(std::is_nothrow_destructible<SHAMapNodeID>{});
-static_assert(std::is_default_constructible<SHAMapNodeID>{});
-static_assert(std::is_copy_constructible<SHAMapNodeID>{});
-static_assert(std::is_copy_assignable<SHAMapNodeID>{});
-static_assert(std::is_move_constructible<SHAMapNodeID>{});
-static_assert(std::is_move_assignable<SHAMapNodeID>{});
-
-static_assert(std::is_nothrow_destructible<SHAMapHash>{});
-static_assert(std::is_default_constructible<SHAMapHash>{});
-static_assert(std::is_copy_constructible<SHAMapHash>{});
-static_assert(std::is_copy_assignable<SHAMapHash>{});
-static_assert(std::is_move_constructible<SHAMapHash>{});
-static_assert(std::is_move_assignable<SHAMapHash>{});
-
-static_assert(std::is_nothrow_destructible<SHAMapTreeNode>{});
-static_assert(!std::is_default_constructible<SHAMapTreeNode>{});
-static_assert(!std::is_copy_constructible<SHAMapTreeNode>{});
-static_assert(!std::is_copy_assignable<SHAMapTreeNode>{});
-static_assert(!std::is_move_constructible<SHAMapTreeNode>{});
-static_assert(!std::is_move_assignable<SHAMapTreeNode>{});
-
-static_assert(std::is_nothrow_destructible<SHAMapInnerNode>{});
-static_assert(!std::is_default_constructible<SHAMapInnerNode>{});
-static_assert(!std::is_copy_constructible<SHAMapInnerNode>{});
-static_assert(!std::is_copy_assignable<SHAMapInnerNode>{});
-static_assert(!std::is_move_constructible<SHAMapInnerNode>{});
-static_assert(!std::is_move_assignable<SHAMapInnerNode>{});
-
-static_assert(std::is_nothrow_destructible<SHAMapLeafNode>{});
-static_assert(!std::is_default_constructible<SHAMapLeafNode>{});
-static_assert(!std::is_copy_constructible<SHAMapLeafNode>{});
-static_assert(!std::is_copy_assignable<SHAMapLeafNode>{});
-static_assert(!std::is_move_constructible<SHAMapLeafNode>{});
-static_assert(!std::is_move_assignable<SHAMapLeafNode>{});
-#endif
-
-inline bool
-operator==(SHAMapItem const& a, SHAMapItem const& b)
-{
-    return a.key() == b.key();
-}
-inline bool
-operator!=(SHAMapItem const& a, SHAMapItem const& b)
-{
-    return a.key() != b.key();
-}
-inline bool
-operator==(SHAMapItem const& a, uint256 const& b)
-{
-    return a.key() == b;
-}
-inline bool
-operator!=(SHAMapItem const& a, uint256 const& b)
-{
-    return a.key() != b;
-}
-
-class SHAMap_test : public beast::unit_test::Suite
-{
-public:
-    static Buffer
-    intToVuc(int v)
-    {
-        Buffer vuc(32);
-        std::fill_n(vuc.data(), vuc.size(), static_cast<std::uint8_t>(v));
-        return vuc;
-    }
-
-    void
-    run() override
-    {
-        using beast::Severity;
-        test::SuiteJournal journal("SHAMap_test", *this);
-
-        run(true, journal);
-        run(false, journal);
-    }
-
-    void
-    run(bool backed, beast::Journal const& journal)
-    {
-        if (backed)
-        {
-            testcase("add/traverse backed");
-        }
-        else
-        {
-            testcase("add/traverse unbacked");
-        }
-
-        tests::TestNodeFamily f(journal);
-
-        // h3 and h4 differ only in the leaf, same terminal node (level 19)
-        constexpr uint256 kH1("092891fe4ef6cee585fdc6fda0e09eb4d386363158ec3321b8123e5a772c6ca7");
-        constexpr uint256 kH2("436ccbac3347baa1f1e53baeef1f43334da88f1f6d70d963b833afd6dfa289fe");
-        constexpr uint256 kH3("b92891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8");
-        constexpr uint256 kH4("b92891fe4ef6cee585fdc6fda2e09eb4d386363158ec3321b8123e5a772c6ca8");
-        constexpr uint256 kH5("a92891fe4ef6cee585fdc6fda0e09eb4d386363158ec3321b8123e5a772c6ca7");
-
-        SHAMap sMap(SHAMapType::FREE, f);
-        sMap.invariants();
-        if (!backed)
-            sMap.setUnbacked();
-
-        auto i1 = makeShamapitem(kH1, intToVuc(1));
-        auto i2 = makeShamapitem(kH2, intToVuc(2));
-        auto i3 = makeShamapitem(kH3, intToVuc(3));
-        auto i4 = makeShamapitem(kH4, intToVuc(4));
-        auto i5 = makeShamapitem(kH5, intToVuc(5));
-
-        unexpected(!sMap.addItem(SHAMapNodeType::TnTransactionNm, makeShamapitem(*i2)), "no add");
-        sMap.invariants();
-        unexpected(!sMap.addItem(SHAMapNodeType::TnTransactionNm, makeShamapitem(*i1)), "no add");
-        sMap.invariants();
-
-        auto i = sMap.begin();
-        auto e = sMap.end();
-        unexpected(i == e || (*i != *i1), "bad traverse");
-        ++i;
-        unexpected(i == e || (*i != *i2), "bad traverse");
-        ++i;
-        unexpected(i != e, "bad traverse");
-        sMap.addItem(SHAMapNodeType::TnTransactionNm, makeShamapitem(*i4));
-        sMap.invariants();
-        sMap.delItem(i2->key());
-        sMap.invariants();
-        sMap.addItem(SHAMapNodeType::TnTransactionNm, makeShamapitem(*i3));
-        sMap.invariants();
-        i = sMap.begin();
-        e = sMap.end();
-        unexpected(i == e || (*i != *i1), "bad traverse");
-        ++i;
-        unexpected(i == e || (*i != *i3), "bad traverse");
-        ++i;
-        unexpected(i == e || (*i != *i4), "bad traverse");
-        ++i;
-        unexpected(i != e, "bad traverse");
-
-        if (backed)
-        {
-            testcase("snapshot backed");
-        }
-        else
-        {
-            testcase("snapshot unbacked");
-        }
-
-        SHAMapHash const mapHash = sMap.getHash();
-        std::shared_ptr<SHAMap> const map2 = sMap.snapShot(false);
-        map2->invariants();
-        unexpected(sMap.getHash() != mapHash, "bad snapshot");
-        unexpected(map2->getHash() != mapHash, "bad snapshot");
-
-        SHAMap::Delta delta;
-        BEAST_EXPECT(sMap.compare(*map2, delta, 100));
-        BEAST_EXPECT(delta.empty());
-
-        unexpected(!sMap.delItem(sMap.begin()->key()), "bad mod");
-        sMap.invariants();
-        unexpected(sMap.getHash() == mapHash, "bad snapshot");
-        unexpected(map2->getHash() != mapHash, "bad snapshot");
-
-        BEAST_EXPECT(sMap.compare(*map2, delta, 100));
-        BEAST_EXPECT(delta.size() == 1);
-        BEAST_EXPECT(delta.begin()->first == kH1);
-        BEAST_EXPECT(delta.begin()->second.first == nullptr);
-        BEAST_EXPECT(delta.begin()->second.second->key() == kH1);
-
-        sMap.dump();
-
-        if (backed)
-        {
-            testcase("build/tear backed");
-        }
-        else
-        {
-            testcase("build/tear unbacked");
-        }
-        {
-            static constexpr std::array keys{
-                uint256(
-                    "b92891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e"
-                    "5a772c6ca8"),
-                uint256(
-                    "b92881fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e"
-                    "5a772c6ca8"),
-                uint256(
-                    "b92691fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e"
-                    "5a772c6ca8"),
-                uint256(
-                    "b92791fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e"
-                    "5a772c6ca8"),
-                uint256(
-                    "b91891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e"
-                    "5a772c6ca8"),
-                uint256(
-                    "b99891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e"
-                    "5a772c6ca8"),
-                uint256(
-                    "f22891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e"
-                    "5a772c6ca8"),
-                uint256(
-                    "292891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e"
-                    "5a772c6ca8")};
-
-            static constexpr std::array kHashes{
-                uint256(
-                    "B7387CFEA0465759ADC718E8C42B52D2309D179B326E239EB5075C"
-                    "64B6281F7F"),
-                uint256(
-                    "FBC195A9592A54AB44010274163CB6BA95F497EC5BA0A883184546"
-                    "7FB2ECE266"),
-                uint256(
-                    "4E7D2684B65DFD48937FFB775E20175C43AF0C94066F7D5679F51A"
-                    "E756795B75"),
-                uint256(
-                    "7A2F312EB203695FFD164E038E281839EEF06A1B99BFC263F3CECC"
-                    "6C74F93E07"),
-                uint256(
-                    "395A6691A372387A703FB0F2C6D2C405DAF307D0817F8F0E207596"
-                    "462B0E3A3E"),
-                uint256(
-                    "D044C0A696DE3169CC70AE216A1564D69DE96582865796142CE7D9"
-                    "8A84D9DDE4"),
-                uint256(
-                    "76DCC77C4027309B5A91AD164083264D70B77B5E43E08AEDA5EBF9"
-                    "4361143615"),
-                uint256(
-                    "DF4220E93ADC6F5569063A01B4DC79F8DB9553B6A3222ADE23DEA0"
-                    "2BBE7230E5")};
-
-            SHAMap map(SHAMapType::FREE, f);
-            if (!backed)
-                map.setUnbacked();
-
-            BEAST_EXPECT(map.getHash() == beast::kZero);
-            for (int k = 0; k < keys.size(); ++k)
-            {
-                BEAST_EXPECT(map.addItem(
-                    SHAMapNodeType::TnTransactionNm, makeShamapitem(keys[k], intToVuc(k))));
-                BEAST_EXPECT(map.getHash().asUInt256() == kHashes[k]);
-                map.invariants();
-            }
-            for (int k = keys.size() - 1; k >= 0; --k)
-            {
-                BEAST_EXPECT(map.getHash().asUInt256() == kHashes[k]);
-                BEAST_EXPECT(map.delItem(keys[k]));
-                map.invariants();
-            }
-            BEAST_EXPECT(map.getHash() == beast::kZero);
-        }
-
-        if (backed)
-        {
-            testcase("iterate backed");
-        }
-        else
-        {
-            testcase("iterate unbacked");
-        }
-
-        {
-            static constexpr std::array keys{
-                uint256(
-                    "f22891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e"
-                    "5a772c6ca8"),
-                uint256(
-                    "b99891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e"
-                    "5a772c6ca8"),
-                uint256(
-                    "b92891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e"
-                    "5a772c6ca8"),
-                uint256(
-                    "b92881fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e"
-                    "5a772c6ca8"),
-                uint256(
-                    "b92791fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e"
-                    "5a772c6ca8"),
-                uint256(
-                    "b92691fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e"
-                    "5a772c6ca8"),
-                uint256(
-                    "b91891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e"
-                    "5a772c6ca8"),
-                uint256(
-                    "292891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e"
-                    "5a772c6ca8")};
-
-            tests::TestNodeFamily tf{journal};
-            SHAMap map{SHAMapType::FREE, tf};
-            if (!backed)
-                map.setUnbacked();
-            for (auto const& k : keys)
-            {
-                map.addItem(SHAMapNodeType::TnTransactionNm, makeShamapitem(k, intToVuc(0)));
-                map.invariants();
-            }
-
-            int h = 7;
-            for (auto const& k : map)
-            {
-                BEAST_EXPECT(k.key() == keys[h]);
-                --h;
-            }
-        }
-    }
-};
-
-class SHAMapPathProof_test : public beast::unit_test::Suite
-{
-    void
-    run() override
-    {
-        test::SuiteJournal journal("SHAMapPathProof_test", *this);
-
-        tests::TestNodeFamily tf{journal};
-        SHAMap map{SHAMapType::FREE, tf};
-        map.setUnbacked();
-
-        uint256 key;
-        uint256 rootHash;
-        std::vector<Blob> goodPath;
-
-        for (unsigned char c = 1; c < 100; ++c)
-        {
-            uint256 k(c);
-            map.addItem(
-                SHAMapNodeType::TnAccountState, makeShamapitem(k, Slice{k.data(), k.size()}));
-            map.invariants();
-
-            auto root = map.getHash().asUInt256();
-            auto path = map.getProofPath(k);
-            BEAST_EXPECT(path);
-            if (!path)
-                break;
-            BEAST_EXPECT(map.verifyProofPath(root, k, *path));
-            if (c == 1)
-            {
-                // extra node
-                path->insert(path->begin(), path->front());
-                BEAST_EXPECT(!map.verifyProofPath(root, k, *path));
-                // wrong key
-                uint256 const wrongKey(c + 1);
-                BEAST_EXPECT(!map.getProofPath(wrongKey));
-            }
-            if (c == 99)
-            {
-                key = k;
-                rootHash = root;
-                goodPath = std::move(*path);
-            }
-        }
-
-        // still good
-        BEAST_EXPECT(map.verifyProofPath(rootHash, key, goodPath));
-        // empty path
-        std::vector<Blob> badPath;
-        BEAST_EXPECT(!map.verifyProofPath(rootHash, key, badPath));
-        // too long
-        badPath = goodPath;
-        badPath.push_back(goodPath.back());
-        BEAST_EXPECT(!map.verifyProofPath(rootHash, key, badPath));
-        // bad node
-        badPath.clear();
-        badPath.emplace_back(100, 100);
-        BEAST_EXPECT(!map.verifyProofPath(rootHash, key, badPath));
-        // bad node type
-        badPath.clear();
-        badPath.push_back(goodPath.front());
-        badPath.front().back()--;  // change node type
-        BEAST_EXPECT(!map.verifyProofPath(rootHash, key, badPath));
-        // all inner
-        badPath.clear();
-        badPath = goodPath;
-        badPath.erase(badPath.begin());
-        BEAST_EXPECT(!map.verifyProofPath(rootHash, key, badPath));
-    }
-};
-
-BEAST_DEFINE_TESTSUITE(SHAMap, shamap, xrpl);
-BEAST_DEFINE_TESTSUITE(SHAMapPathProof, shamap, xrpl);
-}  // namespace xrpl::tests
diff --git a/src/tests/libxrpl/CMakeLists.txt b/src/tests/libxrpl/CMakeLists.txt
index df483a36d8..cafe72eff9 100644
--- a/src/tests/libxrpl/CMakeLists.txt
+++ b/src/tests/libxrpl/CMakeLists.txt
@@ -29,6 +29,8 @@ set(test_modules
     basics
     crypto
     json
+    resource
+    shamap
     tx
     protocol_autogen
 )
diff --git a/src/tests/libxrpl/basics/Buffer.cpp b/src/tests/libxrpl/basics/Buffer.cpp
new file mode 100644
index 0000000000..5b34585fcf
--- /dev/null
+++ b/src/tests/libxrpl/basics/Buffer.cpp
@@ -0,0 +1,260 @@
+#include <xrpl/basics/Buffer.h>
+
+#include <xrpl/basics/Slice.h>
+
+#include <gtest/gtest.h>
+
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+#include <type_traits>
+#include <utility>
+
+namespace xrpl::test {
+
+struct BufferTest : public ::testing::Test
+{
+    static bool
+    sane(Buffer const& b)
+    {
+        if (b.empty())
+            return b.data() == nullptr;
+
+        return b.data() != nullptr;
+    }
+};
+
+TEST_F(BufferTest, buffer)
+{
+    std::uint8_t const data[] = {0xa8, 0xa1, 0x38, 0x45, 0x23, 0xec, 0xe4, 0x23, 0x71, 0x6d, 0x2a,
+                                 0x18, 0xb4, 0x70, 0xcb, 0xf5, 0xac, 0x2d, 0x89, 0x4d, 0x19, 0x9c,
+                                 0xf0, 0x2c, 0x15, 0xd1, 0xf9, 0x9b, 0x66, 0xd2, 0x30, 0xd3};
+
+    Buffer const b0;
+    EXPECT_TRUE(sane(b0));
+    EXPECT_TRUE(b0.empty());
+
+    Buffer b1{0};
+    EXPECT_TRUE(sane(b1));
+    EXPECT_TRUE(b1.empty());
+    std::memcpy(b1.alloc(16), data, 16);
+    EXPECT_TRUE(sane(b1));
+    EXPECT_FALSE(b1.empty());
+    EXPECT_EQ(b1.size(), 16);
+
+    Buffer b2{b1.size()};
+    EXPECT_TRUE(sane(b2));
+    EXPECT_FALSE(b2.empty());
+    EXPECT_EQ(b2.size(), b1.size());
+    std::memcpy(b2.data(), data + 16, 16);
+
+    Buffer b3{data, sizeof(data)};
+    EXPECT_TRUE(sane(b3));
+    EXPECT_FALSE(b3.empty());
+    EXPECT_EQ(b3.size(), sizeof(data));
+    EXPECT_EQ(std::memcmp(b3.data(), data, b3.size()), 0);
+
+    // Check equality and inequality comparisons.
+    // For code readability, we want to use general
+    // EXPECT_TRUE instead of specific EXPECT_EQ etc.
+    EXPECT_TRUE(b0 == b0);
+    EXPECT_TRUE(b0 != b1);
+    EXPECT_TRUE(b1 == b1);
+    EXPECT_TRUE(b1 != b2);
+    EXPECT_TRUE(b2 != b3);
+
+    // Check copy constructors and copy assignments:
+    {
+        Buffer x{b0};
+        EXPECT_EQ(x, b0);
+        EXPECT_TRUE(sane(x));
+        Buffer y{b1};
+        EXPECT_EQ(y, b1);
+        EXPECT_TRUE(sane(y));
+        x = b2;
+        EXPECT_EQ(x, b2);
+        EXPECT_TRUE(sane(x));
+        x = y;
+        EXPECT_EQ(x, y);
+        EXPECT_TRUE(sane(x));
+        y = b3;
+        EXPECT_EQ(y, b3);
+        EXPECT_TRUE(sane(y));
+        x = b0;
+        EXPECT_EQ(x, b0);
+        EXPECT_TRUE(sane(x));
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wself-assign-overloaded"
+#endif
+
+        x = x;
+        EXPECT_EQ(x, b0);
+        EXPECT_TRUE(sane(x));
+        y = y;
+        EXPECT_EQ(y, b3);
+        EXPECT_TRUE(sane(y));
+
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+    }
+
+    // Check move constructor & move assignments:
+    {
+        static_assert(std::is_nothrow_move_constructible_v<Buffer>);
+        static_assert(std::is_nothrow_move_assignable_v<Buffer>);
+
+        {  // Move-construct from empty buf
+            Buffer x;
+            Buffer const y{std::move(x)};
+            EXPECT_TRUE(sane(x));    // NOLINT(bugprone-use-after-move)
+            EXPECT_TRUE(x.empty());  // NOLINT(bugprone-use-after-move)
+            EXPECT_TRUE(sane(y));
+            EXPECT_TRUE(y.empty());
+            EXPECT_EQ(x, y);  // NOLINT(bugprone-use-after-move)
+        }
+
+        {  // Move-construct from non-empty buf
+            Buffer x{b1};
+            Buffer const y{std::move(x)};
+            EXPECT_TRUE(sane(x));    // NOLINT(bugprone-use-after-move)
+            EXPECT_TRUE(x.empty());  // NOLINT(bugprone-use-after-move)
+            EXPECT_TRUE(sane(y));
+            EXPECT_EQ(y, b1);
+        }
+
+        {  // Move assign empty buf to empty buf
+            Buffer x;
+            Buffer y;
+
+            x = std::move(y);
+            EXPECT_TRUE(sane(x));
+            EXPECT_TRUE(x.empty());
+            EXPECT_TRUE(sane(y));    // NOLINT(bugprone-use-after-move)
+            EXPECT_TRUE(y.empty());  // NOLINT(bugprone-use-after-move)
+        }
+
+        {  // Move assign non-empty buf to empty buf
+            Buffer x;
+            Buffer y{b1};
+
+            x = std::move(y);
+            EXPECT_TRUE(sane(x));
+            EXPECT_EQ(x, b1);
+            EXPECT_TRUE(sane(y));    // NOLINT(bugprone-use-after-move)
+            EXPECT_TRUE(y.empty());  // NOLINT(bugprone-use-after-move)
+        }
+
+        {  // Move assign empty buf to non-empty buf
+            Buffer x{b1};
+            Buffer y;
+
+            x = std::move(y);
+            EXPECT_TRUE(sane(x));
+            EXPECT_TRUE(x.empty());
+            EXPECT_TRUE(sane(y));    // NOLINT(bugprone-use-after-move)
+            EXPECT_TRUE(y.empty());  // NOLINT(bugprone-use-after-move)
+        }
+
+        {  // Move assign non-empty buf to non-empty buf
+            Buffer x{b1};
+            Buffer y{b2};
+            Buffer z{b3};
+
+            x = std::move(y);
+            EXPECT_TRUE(sane(x));
+            EXPECT_FALSE(x.empty());
+            EXPECT_TRUE(sane(y));    // NOLINT(bugprone-use-after-move)
+            EXPECT_TRUE(y.empty());  // NOLINT(bugprone-use-after-move)
+
+            x = std::move(z);
+            EXPECT_TRUE(sane(x));
+            EXPECT_FALSE(x.empty());
+            EXPECT_TRUE(sane(z));    // NOLINT(bugprone-use-after-move)
+            EXPECT_TRUE(z.empty());  // NOLINT(bugprone-use-after-move)
+        }
+    }
+
+    {
+        Buffer w{static_cast<Slice>(b0)};
+        EXPECT_TRUE(sane(w));
+        EXPECT_EQ(w, b0);
+
+        Buffer x{static_cast<Slice>(b1)};
+        EXPECT_TRUE(sane(x));
+        EXPECT_EQ(x, b1);
+
+        Buffer y{static_cast<Slice>(b2)};
+        EXPECT_TRUE(sane(y));
+        EXPECT_EQ(y, b2);
+
+        Buffer z{static_cast<Slice>(b3)};
+        EXPECT_TRUE(sane(z));
+        EXPECT_EQ(z, b3);
+
+        // Assign empty slice to empty buffer
+        w = static_cast<Slice>(b0);
+        EXPECT_TRUE(sane(w));
+        EXPECT_EQ(w, b0);
+
+        // Assign non-empty slice to empty buffer
+        w = static_cast<Slice>(b1);
+        EXPECT_TRUE(sane(w));
+        EXPECT_EQ(w, b1);
+
+        // Assign non-empty slice to non-empty buffer
+        x = static_cast<Slice>(b2);
+        EXPECT_TRUE(sane(x));
+        EXPECT_EQ(x, b2);
+
+        // Assign non-empty slice to non-empty buffer
+        y = static_cast<Slice>(z);
+        EXPECT_TRUE(sane(y));
+        EXPECT_EQ(y, z);
+
+        // Assign empty slice to non-empty buffer:
+        z = static_cast<Slice>(b0);
+        EXPECT_TRUE(sane(z));
+        EXPECT_EQ(z, b0);
+    }
+
+    {
+        auto test = [](Buffer const& b, std::size_t i) {
+            Buffer x{b};
+
+            // Try to allocate some number of bytes, possibly
+            // zero (which means clear) and sanity check
+            x(i);
+            EXPECT_TRUE(sane(x));
+            EXPECT_EQ(x.size(), i);
+            EXPECT_EQ((x.data() == nullptr), (i == 0));
+
+            // Try to allocate some more data (always non-zero)
+            x(i + 1);
+            EXPECT_TRUE(sane(x));
+            EXPECT_EQ(x.size(), i + 1);
+            EXPECT_NE(x.data(), nullptr);
+
+            // Try to clear:
+            x.clear();
+            EXPECT_TRUE(sane(x));
+            EXPECT_TRUE(x.empty());
+            EXPECT_EQ(x.data(), nullptr);
+
+            // Try to clear again:
+            x.clear();
+            EXPECT_TRUE(sane(x));
+            EXPECT_TRUE(x.empty());
+            EXPECT_EQ(x.data(), nullptr);
+        };
+
+        for (std::size_t i = 0; i < 16; ++i)
+        {
+            test(b0, i);
+            test(b1, i);
+        }
+    }
+}
+
+}  // namespace xrpl::test
diff --git a/src/tests/libxrpl/basics/FileUtilities.cpp b/src/tests/libxrpl/basics/FileUtilities.cpp
new file mode 100644
index 0000000000..cd24abd696
--- /dev/null
+++ b/src/tests/libxrpl/basics/FileUtilities.cpp
@@ -0,0 +1,94 @@
+#include <xrpl/basics/FileUtilities.h>
+
+#include <xrpl/basics/ByteUtilities.h>
+
+#include <boost/filesystem/operations.hpp>
+#include <boost/filesystem/path.hpp>
+#include <boost/system/detail/errc.hpp>
+#include <boost/system/detail/error_code.hpp>
+
+#include <gtest/gtest.h>
+
+#include <fstream>
+#include <stdexcept>
+#include <string>
+
+namespace xrpl {
+
+namespace {
+
+class TempFile
+{
+public:
+    explicit TempFile(boost::filesystem::path file, std::string const& contents)
+        : dir_(
+              boost::filesystem::temp_directory_path() /
+              boost::filesystem::unique_path("xrpl-file-utilities-%%%%-%%%%-%%%%"))
+        , file_(dir_ / file)
+    {
+        boost::filesystem::create_directory(dir_);
+
+        std::ofstream output(file_.string());
+        if (!output)
+            throw std::runtime_error("Unable to create temporary test file");
+
+        output << contents;
+    }
+
+    ~TempFile()
+    {
+        boost::system::error_code ec;
+        boost::filesystem::remove(file_, ec);
+        boost::filesystem::remove(dir_, ec);
+    }
+
+    [[nodiscard]] boost::filesystem::path const&
+    file() const
+    {
+        return file_;
+    }
+
+private:
+    boost::filesystem::path dir_;
+    boost::filesystem::path file_;
+};
+
+}  // namespace
+
+TEST(FileUtilitiesTest, get_file_contents)
+{
+    using namespace boost::system;
+
+    constexpr char const* kExpectedContents = "This file is very short. That's all we need.";
+
+    TempFile const file("test_file", "This is temporary text that should get overwritten");
+
+    error_code ec;
+    auto const path = file.file();
+
+    writeFileContents(ec, path, kExpectedContents);
+    EXPECT_FALSE(ec);
+
+    {
+        // Test with no max
+        auto const good = getFileContents(ec, path);
+        EXPECT_FALSE(ec);
+        EXPECT_EQ(good, kExpectedContents);
+    }
+
+    {
+        // Test with large max
+        auto const good = getFileContents(ec, path, kilobytes(1));
+        EXPECT_FALSE(ec);
+        EXPECT_EQ(good, kExpectedContents);
+    }
+
+    {
+        // Test with small max
+        auto const bad = getFileContents(ec, path, 16);
+        EXPECT_TRUE(ec && ec.value() == boost::system::errc::file_too_large);
+        EXPECT_TRUE(bad.empty());
+    }
+}
+
+}  // namespace xrpl
diff --git a/src/tests/libxrpl/basics/IOUAmount.cpp b/src/tests/libxrpl/basics/IOUAmount.cpp
new file mode 100644
index 0000000000..46d6d7c5e1
--- /dev/null
+++ b/src/tests/libxrpl/basics/IOUAmount.cpp
@@ -0,0 +1,243 @@
+#include <xrpl/protocol/IOUAmount.h>
+
+#include <xrpl/basics/Number.h>
+#include <xrpl/beast/utility/Zero.h>
+
+#include <gtest/gtest.h>
+
+#include <cstdint>
+#include <limits>
+#include <sstream>
+#include <string>
+
+namespace xrpl {
+
+TEST(IOUAmountTest, zero)
+{
+    IOUAmount const z(0, 0);
+
+    EXPECT_EQ(z.mantissa(), 0);
+    EXPECT_EQ(z.exponent(), -100);
+    EXPECT_FALSE(z);
+    EXPECT_EQ(z.signum(), 0);
+    EXPECT_EQ(z, beast::kZero);
+
+    EXPECT_EQ((z + z), z);
+    EXPECT_EQ((z - z), z);
+    EXPECT_EQ(z, -z);
+
+    IOUAmount const zz(beast::kZero);
+    EXPECT_EQ(z, zz);
+
+    // https://github.com/XRPLF/rippled/issues/5170
+    IOUAmount const zzz{};
+    EXPECT_EQ(zzz, beast::kZero);
+    // EXPECT_EQ(zzz, zz);
+}
+
+TEST(IOUAmountTest, sig_num)
+{
+    IOUAmount const neg(-1, 0);
+    EXPECT_LT(neg.signum(), 0);
+
+    IOUAmount const zer(0, 0);
+    EXPECT_EQ(zer.signum(), 0);
+
+    IOUAmount const pos(1, 0);
+    EXPECT_GT(pos.signum(), 0);
+}
+
+TEST(IOUAmountTest, beast_zero)
+{
+    using beast::kZero;
+
+    {
+        IOUAmount const z(kZero);
+        EXPECT_TRUE(z == kZero);
+        EXPECT_TRUE(z >= kZero);
+        EXPECT_TRUE(z <= kZero);
+        EXPECT_FALSE(z != kZero);
+        EXPECT_FALSE(z > kZero);
+        EXPECT_FALSE(z < kZero);
+    }
+
+    {
+        IOUAmount const neg(-2, 0);
+        EXPECT_TRUE(neg < kZero);
+        EXPECT_TRUE(neg <= kZero);
+        EXPECT_TRUE(neg != kZero);
+        EXPECT_FALSE(neg == kZero);
+    }
+
+    {
+        IOUAmount const pos(2, 0);
+        EXPECT_TRUE(pos > kZero);
+        EXPECT_TRUE(pos >= kZero);
+        EXPECT_TRUE(pos != kZero);
+        EXPECT_FALSE(pos == kZero);
+    }
+}
+
+TEST(IOUAmountTest, comparisons)
+{
+    IOUAmount const n(-2, 0);
+    IOUAmount const z(0, 0);
+    IOUAmount const p(2, 0);
+    // For code readability, we want to use general
+    // EXPECT_TRUE instead of specific EXPECT_EQ etc.
+    EXPECT_TRUE(z == z);
+    EXPECT_TRUE(z >= z);
+    EXPECT_TRUE(z <= z);
+    EXPECT_TRUE(z == -z);
+    // NOLINTBEGIN(misc-redundant-expression)
+    EXPECT_FALSE(z > z);
+    EXPECT_FALSE(z < z);
+    EXPECT_FALSE(z != z);
+    // NOLINTEND(misc-redundant-expression)
+    EXPECT_FALSE(z != -z);
+
+    EXPECT_TRUE(n < z);
+    EXPECT_TRUE(n <= z);
+    EXPECT_TRUE(n != z);
+    EXPECT_FALSE(n > z);
+    EXPECT_FALSE(n >= z);
+    EXPECT_FALSE(n == z);
+
+    EXPECT_TRUE(p > z);
+    EXPECT_TRUE(p >= z);
+    EXPECT_TRUE(p != z);
+    EXPECT_FALSE(p < z);
+    EXPECT_FALSE(p <= z);
+    EXPECT_FALSE(p == z);
+
+    EXPECT_TRUE(n < p);
+    EXPECT_TRUE(n <= p);
+    EXPECT_TRUE(n != p);
+    EXPECT_FALSE(n > p);
+    EXPECT_FALSE(n >= p);
+    EXPECT_FALSE(n == p);
+
+    EXPECT_TRUE(p > n);
+    EXPECT_TRUE(p >= n);
+    EXPECT_TRUE(p != n);
+    EXPECT_FALSE(p < n);
+    EXPECT_FALSE(p <= n);
+    EXPECT_FALSE(p == n);
+
+    EXPECT_TRUE(p > -p);
+    EXPECT_TRUE(p >= -p);
+    EXPECT_TRUE(p != -p);
+
+    EXPECT_TRUE(n < -n);
+    EXPECT_TRUE(n <= -n);
+    EXPECT_TRUE(n != -n);
+}
+
+TEST(IOUAmountTest, to_string)
+{
+    auto test = [](IOUAmount const& n, std::string const& expected) {
+        auto const result = to_string(n);
+        std::stringstream ss;
+        ss << "to_string(" << result << "). Expected: " << expected;
+        EXPECT_EQ(result, expected) << ss.str();
+    };
+
+    for (auto const mantissaSize : MantissaRange::getAllScales())
+    {
+        NumberMantissaScaleGuard const mg(mantissaSize);
+
+        test(IOUAmount(-2, 0), "-2");
+        test(IOUAmount(0, 0), "0");
+        test(IOUAmount(2, 0), "2");
+        test(IOUAmount(25, -3), "0.025");
+        test(IOUAmount(-25, -3), "-0.025");
+        test(IOUAmount(25, 1), "250");
+        test(IOUAmount(-25, 1), "-250");
+        test(IOUAmount(2, 20), "2e20");
+        test(IOUAmount(-2, -20), "-2e-20");
+    }
+}
+
+TEST(IOUAmountTest, mul_ratio)
+{
+    /* The range for the mantissa when normalized */
+    constexpr std::int64_t kMinMantissa = 1000000000000000ull;
+    constexpr std::int64_t kMaxMantissa = 9999999999999999ull;
+    // log(2,maxMantissa) ~ 53.15
+    /* The range for the exponent when normalized */
+    constexpr int kMinExponent = -96;
+    constexpr int kMaxExponent = 80;
+    constexpr auto kMaxUInt = std::numeric_limits<std::uint32_t>::max();
+
+    {
+        // multiply by a number that would overflow the mantissa, then
+        // divide by the same number, and check we didn't lose any value
+        IOUAmount const bigMan(kMaxMantissa, 0);
+        EXPECT_EQ(bigMan, mulRatio(bigMan, kMaxUInt, kMaxUInt, true));
+        // rounding mode shouldn't matter as the result is exact
+        EXPECT_EQ(bigMan, mulRatio(bigMan, kMaxUInt, kMaxUInt, false));
+    }
+    {
+        // Similar test as above, but for negative values
+        IOUAmount const bigMan(-kMaxMantissa, 0);
+        EXPECT_EQ(bigMan, mulRatio(bigMan, kMaxUInt, kMaxUInt, true));
+        // rounding mode shouldn't matter as the result is exact
+        EXPECT_EQ(bigMan, mulRatio(bigMan, kMaxUInt, kMaxUInt, false));
+    }
+
+    {
+        // small amounts
+        IOUAmount const tiny(kMinMantissa, kMinExponent);
+        // Round up should give the smallest allowable number
+        EXPECT_EQ(tiny, mulRatio(tiny, 1, kMaxUInt, true));
+        EXPECT_EQ(tiny, mulRatio(tiny, kMaxUInt - 1, kMaxUInt, true));
+        // rounding down should be zero
+        EXPECT_EQ(beast::kZero, mulRatio(tiny, 1, kMaxUInt, false));
+        EXPECT_EQ(beast::kZero, mulRatio(tiny, kMaxUInt - 1, kMaxUInt, false));
+
+        // tiny negative numbers
+        IOUAmount const tinyNeg(-kMinMantissa, kMinExponent);
+        // Round up should give zero
+        EXPECT_EQ(beast::kZero, mulRatio(tinyNeg, 1, kMaxUInt, true));
+        EXPECT_EQ(beast::kZero, mulRatio(tinyNeg, kMaxUInt - 1, kMaxUInt, true));
+        // rounding down should be tiny
+        EXPECT_EQ(tinyNeg, mulRatio(tinyNeg, 1, kMaxUInt, false));
+        EXPECT_EQ(tinyNeg, mulRatio(tinyNeg, kMaxUInt - 1, kMaxUInt, false));
+    }
+
+    {  // rounding
+        {
+            IOUAmount const one(1, 0);
+            auto const rup = mulRatio(one, kMaxUInt - 1, kMaxUInt, true);
+            auto const rdown = mulRatio(one, kMaxUInt - 1, kMaxUInt, false);
+            EXPECT_EQ(rup.mantissa() - rdown.mantissa(), 1);
+        }
+        {
+            IOUAmount const big(kMaxMantissa, kMaxExponent);
+            auto const rup = mulRatio(big, kMaxUInt - 1, kMaxUInt, true);
+            auto const rdown = mulRatio(big, kMaxUInt - 1, kMaxUInt, false);
+            EXPECT_EQ(rup.mantissa() - rdown.mantissa(), 1);
+        }
+
+        {
+            IOUAmount const negOne(-1, 0);
+            auto const rup = mulRatio(negOne, kMaxUInt - 1, kMaxUInt, true);
+            auto const rdown = mulRatio(negOne, kMaxUInt - 1, kMaxUInt, false);
+            EXPECT_EQ(rup.mantissa() - rdown.mantissa(), 1);
+        }
+    }
+
+    {
+        // division by zero
+        IOUAmount const one(1, 0);
+        EXPECT_ANY_THROW({ mulRatio(one, 1, 0, true); });
+    }
+
+    {
+        // overflow
+        IOUAmount const big(kMaxMantissa, kMaxExponent);
+        EXPECT_ANY_THROW({ mulRatio(big, 2, 0, true); });
+    }
+}
+
+}  // namespace xrpl
diff --git a/src/tests/libxrpl/basics/IntrusiveShared.cpp b/src/tests/libxrpl/basics/IntrusiveShared.cpp
new file mode 100644
index 0000000000..e798cd1ccc
--- /dev/null
+++ b/src/tests/libxrpl/basics/IntrusiveShared.cpp
@@ -0,0 +1,844 @@
+#include <xrpl/basics/IntrusivePointer.h>    // IWYU pragma: keep
+#include <xrpl/basics/IntrusivePointer.ipp>  // IWYU pragma: keep
+#include <xrpl/basics/IntrusiveRefCounts.h>
+
+#include <gtest/gtest.h>
+
+#include <algorithm>
+#include <array>
+#include <atomic>
+#include <chrono>  // IWYU pragma: keep
+#include <condition_variable>
+#include <cstddef>
+#include <cstdint>
+#include <functional>
+#include <latch>
+#include <mutex>
+#include <optional>
+#include <random>
+#include <stdexcept>
+#include <thread>
+#include <utility>
+#include <variant>
+#include <vector>
+
+namespace xrpl::tests {
+
+/*
+ * Experimentally, we discovered that using std::barrier performs extremely
+ * poorly (~1 hour vs ~1 minute to run the test suite) in certain macOS
+ * environments. To unblock our macOS CI pipeline, we replaced std::barrier with a
+ * custom mutex-based barrier (Barrier) that significantly improves performance
+ * without compromising correctness. For future reference, if we ever consider
+ * reintroducing std::barrier, the following configuration is known to exhibit the
+ * problem:
+ *
+ *     Model Name: Mac mini
+ *     Model Identifier: Mac14,3
+ *     Model Number: Z16K000R4LL/A
+ *     Chip: Apple M2
+ *     Total Number of Cores: 8 (4 performance and 4 efficiency)
+ *     Memory: 24 GB
+ *     System Firmware Version: 11881.41.5
+ *     OS Loader Version: 11881.1.1
+ *     Apple clang version 16.0.0 (clang-1600.0.26.3)
+ *     Target: arm64-apple-darwin24.0.0
+ *     Thread model: posix
+ *
+ */
+struct Barrier
+{
+    std::mutex mtx;
+    std::condition_variable cv;
+    int count;
+    int const initial;
+    std::size_t generation{0};
+
+    explicit Barrier(int n) : count(n), initial(n)
+    {
+    }
+
+    void
+    arriveAndWait()
+    {
+        std::unique_lock lock(mtx);
+        auto const currentGeneration = generation;
+        if (--count == 0)
+        {
+            ++generation;
+            count = initial;
+            cv.notify_all();
+        }
+        else
+        {
+            cv.wait(lock, [&] { return generation != currentGeneration; });
+        }
+    }
+};
+
+namespace {
+enum class TrackedState : std::uint8_t {
+    Uninitialized,
+    Alive,
+    PartiallyDeletedStarted,
+    PartiallyDeleted,
+    DeletedStarted,
+    Deleted
+};
+
+class TIBase : public IntrusiveRefCounts
+{
+public:
+    static constexpr std::size_t kMaxStates = 128;
+    static std::array<std::atomic<TrackedState>, kMaxStates> state;
+    static std::atomic<std::size_t> nextId;
+    static TrackedState
+    getState(std::size_t id)
+    {
+        if (id >= state.size())
+            throw std::out_of_range("TIBase state id out of range");
+
+        return state[id].load(std::memory_order_acquire);
+    }
+    static void
+    resetStates(bool resetCallback)
+    {
+        for (std::size_t i = 0; i < kMaxStates; ++i)
+        {
+            state[i].store(TrackedState::Uninitialized, std::memory_order_release);
+        }
+        nextId.store(0, std::memory_order_release);
+        if (resetCallback)
+            TIBase::tracingCallback = [](TrackedState, std::optional<TrackedState>) {};
+    }
+
+    struct ResetStatesGuard
+    {
+        bool resetCallback{false};
+
+        ResetStatesGuard(bool resetCallback) : resetCallback{resetCallback}
+        {
+            TIBase::resetStates(resetCallback);
+        }
+        ~ResetStatesGuard()
+        {
+            TIBase::resetStates(resetCallback);
+        }
+    };
+
+    TIBase() : id{checkoutID()}
+    {
+        state[id].store(TrackedState::Alive, std::memory_order_relaxed);
+    }
+    ~TIBase() override
+    {
+        using enum TrackedState;
+
+        tracingCallback(state[id].load(std::memory_order_relaxed), DeletedStarted);
+
+        // Use relaxed memory order to try to avoid atomic operations from
+        // adding additional memory synchronizations that may hide threading
+        // errors in the underlying shared pointer class.
+        state[id].store(DeletedStarted, std::memory_order_relaxed);
+
+        tracingCallback(DeletedStarted, Deleted);
+
+        state[id].store(TrackedState::Deleted, std::memory_order_relaxed);
+
+        tracingCallback(TrackedState::Deleted, std::nullopt);
+    }
+
+    void
+    partialDestructor() const
+    {
+        using enum TrackedState;
+
+        tracingCallback(state[id].load(std::memory_order_relaxed), PartiallyDeletedStarted);
+
+        state[id].store(PartiallyDeletedStarted, std::memory_order_relaxed);
+
+        tracingCallback(PartiallyDeletedStarted, PartiallyDeleted);
+
+        state[id].store(PartiallyDeleted, std::memory_order_relaxed);
+
+        tracingCallback(PartiallyDeleted, std::nullopt);
+    }
+
+    static std::function<void(TrackedState, std::optional<TrackedState>)> tracingCallback;
+
+    std::size_t const id;
+
+private:
+    static std::size_t
+    checkoutID()
+    {
+        auto const id = nextId.fetch_add(1, std::memory_order_acq_rel);
+        if (id >= state.size())
+            throw std::out_of_range("TIBase state capacity exceeded");
+
+        return id;
+    }
+};
+
+std::array<std::atomic<TrackedState>, TIBase::kMaxStates> TIBase::state;
+std::atomic<std::size_t> TIBase::nextId{0};
+
+std::function<void(TrackedState, std::optional<TrackedState>)> TIBase::tracingCallback =
+    [](TrackedState, std::optional<TrackedState>) {};
+
+}  // namespace
+
+TEST(IntrusiveSharedTest, basics)
+{
+    {
+        TIBase::ResetStatesGuard const rsg{true};
+
+        TIBase const b;
+        EXPECT_EQ(b.useCount(), 1);
+        b.addWeakRef();
+        EXPECT_EQ(b.useCount(), 1);
+        auto s = b.releaseStrongRef();
+        EXPECT_EQ(s, ReleaseStrongRefAction::PartialDestroy);
+        EXPECT_EQ(b.useCount(), 0);
+        TIBase const* pb = &b;
+        partialDestructorFinished(&pb);
+        EXPECT_FALSE(pb);
+        auto w = b.releaseWeakRef();
+        EXPECT_EQ(w, ReleaseWeakRefAction::Destroy);
+    }
+
+    std::vector<SharedIntrusive<TIBase>> strong;
+    std::vector<WeakIntrusive<TIBase>> weak;
+    {
+        TIBase::ResetStatesGuard const rsg{true};
+
+        using enum TrackedState;
+        auto b = makeSharedIntrusive<TIBase>();
+        auto id = b->id;
+        EXPECT_EQ(TIBase::getState(id), Alive);
+        EXPECT_EQ(b->useCount(), 1);
+        for (int i = 0; i < 10; ++i)
+        {
+            strong.push_back(b);
+        }
+        b.reset();
+        EXPECT_EQ(TIBase::getState(id), Alive);
+        strong.resize(strong.size() - 1);
+        EXPECT_EQ(TIBase::getState(id), Alive);
+        strong.clear();
+        EXPECT_EQ(TIBase::getState(id), Deleted);
+
+        b = makeSharedIntrusive<TIBase>();
+        id = b->id;
+        EXPECT_EQ(TIBase::getState(id), Alive);
+        EXPECT_EQ(b->useCount(), 1);
+        for (int i = 0; i < 10; ++i)
+        {
+            weak.emplace_back(b);
+            EXPECT_EQ(b->useCount(), 1);
+        }
+        EXPECT_EQ(TIBase::getState(id), Alive);
+        weak.resize(weak.size() - 1);
+        EXPECT_EQ(TIBase::getState(id), Alive);
+        b.reset();
+        EXPECT_EQ(TIBase::getState(id), PartiallyDeleted);
+        while (!weak.empty())
+        {
+            weak.resize(weak.size() - 1);
+            if (!weak.empty())
+            {
+                EXPECT_EQ(TIBase::getState(id), PartiallyDeleted);
+            }
+        }
+        EXPECT_EQ(TIBase::getState(id), Deleted);
+    }
+    {
+        TIBase::ResetStatesGuard const rsg{true};
+
+        using enum TrackedState;
+        auto b = makeSharedIntrusive<TIBase>();
+        auto id = b->id;
+        EXPECT_EQ(TIBase::getState(id), Alive);
+        WeakIntrusive<TIBase> w{b};
+        EXPECT_EQ(TIBase::getState(id), Alive);
+        auto s = w.lock();
+        EXPECT_TRUE(s && s->useCount() == 2);
+        b.reset();
+        EXPECT_TRUE(TIBase::getState(id) == Alive);
+        EXPECT_TRUE(s && s->useCount() == 1);
+        s.reset();
+        EXPECT_EQ(TIBase::getState(id), PartiallyDeleted);
+        EXPECT_TRUE(w.expired());
+        s = w.lock();
+        // Cannot convert a weak pointer to a strong pointer if object is
+        // already partially deleted
+        EXPECT_FALSE(s);
+        w.reset();
+        EXPECT_EQ(TIBase::getState(id), Deleted);
+    }
+    {
+        TIBase::ResetStatesGuard const rsg{true};
+
+        using enum TrackedState;
+        using swu = SharedWeakUnion<TIBase>;
+        swu b = makeSharedIntrusive<TIBase>();
+        EXPECT_TRUE(b.isStrong() && b.useCount() == 1);
+        auto id = b.get()->id;
+        EXPECT_EQ(TIBase::getState(id), Alive);
+        swu w = b;
+        EXPECT_TRUE(TIBase::getState(id) == Alive);
+        EXPECT_TRUE(w.isStrong() && b.useCount() == 2);
+        w.convertToWeak();
+        EXPECT_TRUE(w.isWeak() && b.useCount() == 1);
+        swu s = w;
+        EXPECT_TRUE(s.isWeak() && b.useCount() == 1);
+        s.convertToStrong();
+        EXPECT_TRUE(s.isStrong() && b.useCount() == 2);
+        b.reset();
+        EXPECT_EQ(TIBase::getState(id), Alive);
+        EXPECT_EQ(s.useCount(), 1);
+        EXPECT_FALSE(w.expired());
+        s.reset();
+        EXPECT_EQ(TIBase::getState(id), PartiallyDeleted);
+        EXPECT_TRUE(w.expired());
+        w.convertToStrong();
+        // Cannot convert a weak pointer to a strong pointer if object is
+        // already partially deleted
+        EXPECT_TRUE(w.isWeak());
+        w.reset();
+        EXPECT_EQ(TIBase::getState(id), Deleted);
+    }
+    {
+        // Testing SharedWeakUnion assignment operator
+
+        TIBase::ResetStatesGuard const rsg{true};
+
+        auto strong1 = makeSharedIntrusive<TIBase>();
+        auto strong2 = makeSharedIntrusive<TIBase>();
+
+        auto id1 = strong1->id;
+        auto id2 = strong2->id;
+
+        EXPECT_NE(id1, id2);
+
+        SharedWeakUnion<TIBase> union1 = strong1;
+        SharedWeakUnion<TIBase> union2 = strong2;
+
+        EXPECT_TRUE(union1.isStrong());
+        EXPECT_TRUE(union2.isStrong());
+        EXPECT_EQ(union1.get(), strong1.get());
+        EXPECT_EQ(union2.get(), strong2.get());
+
+        // 1) Normal assignment: explicitly calls SharedWeakUnion assignment
+        union1 = union2;
+        EXPECT_TRUE(union1.isStrong());
+        EXPECT_TRUE(union2.isStrong());
+        EXPECT_EQ(union1.get(), union2.get());
+        EXPECT_EQ(TIBase::getState(id1), TrackedState::Alive);
+        EXPECT_EQ(TIBase::getState(id2), TrackedState::Alive);
+
+        // 2) Test self-assignment
+        EXPECT_TRUE(union1.isStrong());
+        EXPECT_EQ(TIBase::getState(id1), TrackedState::Alive);
+        int const initialRefCount = strong1->useCount();
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wself-assign-overloaded"
+        union1 = union1;  // Self-assignment
+#pragma clang diagnostic pop
+        EXPECT_TRUE(union1.isStrong());
+        EXPECT_EQ(TIBase::getState(id1), TrackedState::Alive);
+        EXPECT_EQ(strong1->useCount(), initialRefCount);
+
+        // 3) Test assignment from null union pointer
+        union1 = SharedWeakUnion<TIBase>();
+        EXPECT_EQ(union1.get(), nullptr);
+
+        // 4) Test assignment to expired union pointer
+        strong2.reset();
+        union2.reset();
+        union1 = union2;
+        EXPECT_EQ(union1.get(), nullptr);
+        EXPECT_EQ(TIBase::getState(id2), TrackedState::Deleted);
+    }
+}
+
+TEST(IntrusiveSharedTest, partial_delete)
+{
+    // This test creates two threads. One with a strong pointer and one
+    // with a weak pointer. The strong pointer is reset while the weak
+    // pointer still holds a reference, triggering a partial delete.
+    // While the partial delete function runs (a sleep is inserted) the
+    // weak pointer is reset. The destructor should wait to run until
+    // after the partial delete function has completed running.
+
+    using enum TrackedState;
+
+    TIBase::ResetStatesGuard const rsg{true};
+
+    auto strong = makeSharedIntrusive<TIBase>();
+    WeakIntrusive<TIBase> weak{strong};
+    std::atomic<bool> destructorRan{false};
+    std::atomic<bool> partialDeleteRan{false};
+    std::latch partialDeleteStartedSyncPoint{2};
+    strong->tracingCallback = [&](TrackedState cur, std::optional<TrackedState> next) {
+        using enum TrackedState;
+        if (next == DeletedStarted)
+        {
+            // strong goes out of scope while weak is still in scope
+            // This checks that partialDelete has run to completion
+            // before the destructor is called. A sleep is inserted
+            // inside the partial delete to make sure the destructor is
+            // given an opportunity to run during partial delete.
+            EXPECT_EQ(cur, PartiallyDeleted);
+        }
+        if (next == PartiallyDeletedStarted)
+        {
+            partialDeleteStartedSyncPoint.arrive_and_wait();
+            using namespace std::chrono_literals;
+            // Sleep and let the weak pointer go out of scope,
+            // potentially triggering a destructor while partial delete
+            // is running. The test is to make sure that doesn't happen.
+            std::this_thread::sleep_for(800ms);
+        }
+        if (next == PartiallyDeleted)
+        {
+            EXPECT_FALSE(partialDeleteRan.exchange(true) || destructorRan.load());
+        }
+        if (next == Deleted)
+        {
+            EXPECT_FALSE(destructorRan.exchange(true));
+        }
+    };
+    std::thread t1{[&] {
+        partialDeleteStartedSyncPoint.arrive_and_wait();
+        weak.reset();  // Trigger a full delete as soon as the partial
+                       // delete starts
+    }};
+    std::thread t2{[&] {
+        strong.reset();  // Trigger a partial delete
+    }};
+    t1.join();
+    t2.join();
+
+    EXPECT_TRUE(destructorRan.load() && partialDeleteRan.load());
+}
+
+TEST(IntrusiveSharedTest, destructor)
+{
+    // This test creates two threads. One with a strong pointer and one
+    // with a weak pointer. The weak pointer is reset while the strong
+    // pointer still holds a reference. Then the strong pointer is
+    // reset. Only the destructor should run. The partial destructor
+    // should not be called. Since the weak reset runs to completion
+    // before the strong pointer is reset, threading doesn't add much to
+    // this test, but there is no harm in keeping it.
+
+    using enum TrackedState;
+
+    TIBase::ResetStatesGuard const rsg{true};
+
+    auto strong = makeSharedIntrusive<TIBase>();
+    WeakIntrusive<TIBase> weak{strong};
+    std::atomic<bool> destructorRan{false};
+    std::atomic<bool> partialDeleteRan{false};
+    std::latch weakResetSyncPoint{2};
+    strong->tracingCallback = [&](TrackedState cur, std::optional<TrackedState> next) {
+        using enum TrackedState;
+        if (next == PartiallyDeleted)
+        {
+            EXPECT_FALSE(partialDeleteRan.exchange(true) || destructorRan.load());
+        }
+        if (next == Deleted)
+        {
+            EXPECT_FALSE(destructorRan.exchange(true));
+        }
+    };
+    std::thread t1{[&] {
+        weak.reset();
+        weakResetSyncPoint.arrive_and_wait();
+    }};
+    std::thread t2{[&] {
+        weakResetSyncPoint.arrive_and_wait();
+        strong.reset();  // Trigger a partial delete
+    }};
+    t1.join();
+    t2.join();
+
+    EXPECT_TRUE(destructorRan.load() && !partialDeleteRan.load());
+}
+
+TEST(IntrusiveSharedTest, multithreaded_clear_mixed_variant)
+{
+    // This test creates and destroys many strong and weak pointers in a
+    // loop. There is a random mix of strong and weak pointers stored in
+    // a vector (held as a variant). Both threads clear all the pointers
+    // and check that the invariants hold.
+
+    using enum TrackedState;
+    TIBase::ResetStatesGuard const rsg{true};
+
+    std::atomic<int> destructionState{0};
+    // returns destructorRan and partialDestructorRan (in that order)
+    auto getDestructorState = [&]() -> std::pair<bool, bool> {
+        int const s = destructionState.load(std::memory_order_relaxed);
+        return {(s & 1) != 0, (s & 2) != 0};
+    };
+    auto setDestructorRan = [&]() -> void {
+        destructionState.fetch_or(1, std::memory_order_acq_rel);
+    };
+    auto setPartialDeleteRan = [&]() -> void {
+        destructionState.fetch_or(2, std::memory_order_acq_rel);
+    };
+    auto tracingCallback = [&](TrackedState cur, std::optional<TrackedState> next) {
+        using enum TrackedState;
+        auto [destructorRan, partialDeleteRan] = getDestructorState();
+        if (next == PartiallyDeleted)
+        {
+            EXPECT_FALSE(partialDeleteRan || destructorRan);
+            setPartialDeleteRan();
+        }
+        if (next == Deleted)
+        {
+            EXPECT_FALSE(destructorRan);
+            setDestructorRan();
+        }
+    };
+    auto createVecOfPointers = [&](auto const& toClone, std::default_random_engine& eng)
+        -> std::vector<std::variant<SharedIntrusive<TIBase>, WeakIntrusive<TIBase>>> {
+        std::vector<std::variant<SharedIntrusive<TIBase>, WeakIntrusive<TIBase>>> result;
+        std::uniform_int_distribution<> toCreateDist(4, 64);
+        std::uniform_int_distribution<> isStrongDist(0, 1);
+        auto numToCreate = toCreateDist(eng);
+        result.reserve(numToCreate);
+        for (int i = 0; i < numToCreate; ++i)
+        {
+            if (isStrongDist(eng))
+            {
+                result.emplace_back(SharedIntrusive<TIBase>(toClone));
+            }
+            else
+            {
+                result.emplace_back(WeakIntrusive<TIBase>(toClone));
+            }
+        }
+        return result;
+    };
+    constexpr int kLoopIters = 2 * 1024;
+    constexpr int kNumThreads = 16;
+    std::vector<SharedIntrusive<TIBase>> toClone;
+    Barrier loopStartSyncPoint{kNumThreads};
+    Barrier postCreateToCloneSyncPoint{kNumThreads};
+    Barrier postCreateVecOfPointersSyncPoint{kNumThreads};
+    auto engines = [&]() -> std::vector<std::default_random_engine> {
+        std::random_device rd;
+        std::vector<std::default_random_engine> result;
+        result.reserve(kNumThreads);
+        for (int i = 0; i < kNumThreads; ++i)
+            result.emplace_back(rd());
+        return result;
+    }();
+
+    // cloneAndDestroy clones the strong pointer into a vector of mixed
+    // strong and weak pointers and destroys them all at once.
+    // threadId==0 is special.
+    auto cloneAndDestroy = [&](int threadId) {
+        for (int i = 0; i < kLoopIters; ++i)
+        {
+            // ------ Sync Point ------
+            loopStartSyncPoint.arriveAndWait();
+
+            // only thread 0 should reset the state
+            std::optional<TIBase::ResetStatesGuard> rsg;
+            if (threadId == 0)
+            {
+                // Thread 0 is the genesis thread. It creates the strong
+                // pointers to be cloned by the other threads. This
+                // thread will also check that the destructor ran and
+                // clear the temporary variables.
+
+                rsg.emplace(false);
+                auto [destructorRan, partialDeleteRan] = getDestructorState();
+                EXPECT_TRUE(i == 0 || destructorRan);
+                destructionState.store(0, std::memory_order_release);
+
+                toClone.clear();
+                toClone.resize(kNumThreads);
+                auto strong = makeSharedIntrusive<TIBase>();
+                strong->tracingCallback = tracingCallback;
+                std::ranges::fill(toClone, strong);
+            }
+
+            // ------ Sync Point ------
+            postCreateToCloneSyncPoint.arriveAndWait();
+
+            auto v = createVecOfPointers(toClone[threadId], engines[threadId]);
+            toClone[threadId].reset();
+
+            // ------ Sync Point ------
+            postCreateVecOfPointersSyncPoint.arriveAndWait();
+
+            v.clear();
+        }
+    };
+    std::vector<std::thread> threads;
+    threads.reserve(kNumThreads);
+    for (int i = 0; i < kNumThreads; ++i)
+    {
+        threads.emplace_back(cloneAndDestroy, i);
+    }
+    for (int i = 0; i < kNumThreads; ++i)
+    {
+        threads[i].join();
+    }
+}
+
+TEST(IntrusiveSharedTest, multithreaded_clear_mixed_union)
+{
+    // This test creates and destroys many SharedWeak pointers in a
+    // loop. All the pointers start as strong and a loop randomly
+    // convert them between strong and weak pointers. Both threads clear
+    // all the pointers and check that the invariants hold.
+    //
+    // Note: This test also differs from the test above in that the pointers
+    // randomly change from strong to weak and from weak to strong in a
+    // loop. This can't be done in the variant test above because variant is
+    // not thread safe while the SharedWeakUnion is thread safe.
+
+    using enum TrackedState;
+
+    TIBase::ResetStatesGuard const rsg{true};
+
+    std::atomic<int> destructionState{0};
+    // returns destructorRan and partialDestructorRan (in that order)
+    auto getDestructorState = [&]() -> std::pair<bool, bool> {
+        int const s = destructionState.load(std::memory_order_relaxed);
+        return {(s & 1) != 0, (s & 2) != 0};
+    };
+    auto setDestructorRan = [&]() -> void {
+        destructionState.fetch_or(1, std::memory_order_acq_rel);
+    };
+    auto setPartialDeleteRan = [&]() -> void {
+        destructionState.fetch_or(2, std::memory_order_acq_rel);
+    };
+    auto tracingCallback = [&](TrackedState cur, std::optional<TrackedState> next) {
+        using enum TrackedState;
+        auto [destructorRan, partialDeleteRan] = getDestructorState();
+        if (next == PartiallyDeleted)
+        {
+            EXPECT_FALSE(partialDeleteRan || destructorRan);
+            setPartialDeleteRan();
+        }
+        if (next == Deleted)
+        {
+            EXPECT_FALSE(destructorRan);
+            setDestructorRan();
+        }
+    };
+    auto createVecOfPointers =
+        [&](auto const& toClone,
+            std::default_random_engine& eng) -> std::vector<SharedWeakUnion<TIBase>> {
+        std::vector<SharedWeakUnion<TIBase>> result;
+        std::uniform_int_distribution<> toCreateDist(4, 64);
+        auto numToCreate = toCreateDist(eng);
+        result.reserve(numToCreate);
+        for (int i = 0; i < numToCreate; ++i)
+            result.emplace_back(SharedIntrusive<TIBase>(toClone));
+        return result;
+    };
+    constexpr int kLoopIters = 2 * 1024;
+    constexpr int kFlipPointersLoopIters = 256;
+    constexpr int kNumThreads = 16;
+    std::vector<SharedIntrusive<TIBase>> toClone;
+    Barrier loopStartSyncPoint{kNumThreads};
+    Barrier postCreateToCloneSyncPoint{kNumThreads};
+    Barrier postCreateVecOfPointersSyncPoint{kNumThreads};
+    Barrier postFlipPointersLoopSyncPoint{kNumThreads};
+    auto engines = [&]() -> std::vector<std::default_random_engine> {
+        std::random_device rd;
+        std::vector<std::default_random_engine> result;
+        result.reserve(kNumThreads);
+        for (int i = 0; i < kNumThreads; ++i)
+            result.emplace_back(rd());
+        return result;
+    }();
+
+    // cloneAndDestroy clones the strong pointer into a vector of
+    // mixed strong and weak pointers, runs a loop that randomly
+    // changes strong pointers to weak pointers,  and destroys them
+    // all at once.
+    auto cloneAndDestroy = [&](int threadId) {
+        for (int i = 0; i < kLoopIters; ++i)
+        {
+            // ------ Sync Point ------
+            loopStartSyncPoint.arriveAndWait();
+
+            // only thread 0 should reset the state
+            std::optional<TIBase::ResetStatesGuard> rsg;
+            if (threadId == 0)
+            {
+                // threadId 0 is the genesis thread. It creates the
+                // strong point to be cloned by the other threads. This
+                // thread will also check that the destructor ran and
+                // clear the temporary variables.
+                rsg.emplace(false);
+                auto [destructorRan, partialDeleteRan] = getDestructorState();
+                EXPECT_TRUE(i == 0 || destructorRan);
+                destructionState.store(0, std::memory_order_release);
+
+                toClone.clear();
+                toClone.resize(kNumThreads);
+                auto strong = makeSharedIntrusive<TIBase>();
+                strong->tracingCallback = tracingCallback;
+                std::ranges::fill(toClone, strong);
+            }
+
+            // ------ Sync Point ------
+            postCreateToCloneSyncPoint.arriveAndWait();
+
+            auto v = createVecOfPointers(toClone[threadId], engines[threadId]);
+            toClone[threadId].reset();
+
+            // ------ Sync Point ------
+            postCreateVecOfPointersSyncPoint.arriveAndWait();
+
+            std::uniform_int_distribution<> isStrongDist(0, 1);
+            for (int f = 0; f < kFlipPointersLoopIters; ++f)
+            {
+                for (auto& p : v)
+                {
+                    if (isStrongDist(engines[threadId]))
+                    {
+                        p.convertToStrong();
+                    }
+                    else
+                    {
+                        p.convertToWeak();
+                    }
+                }
+            }
+
+            // ------ Sync Point ------
+            postFlipPointersLoopSyncPoint.arriveAndWait();
+
+            v.clear();
+        }
+    };
+    std::vector<std::thread> threads;
+    threads.reserve(kNumThreads);
+    for (int i = 0; i < kNumThreads; ++i)
+    {
+        threads.emplace_back(cloneAndDestroy, i);
+    }
+    for (int i = 0; i < kNumThreads; ++i)
+    {
+        threads[i].join();
+    }
+}
+
+TEST(IntrusiveSharedTest, multithreaded_locking_weak)
+{
+    // This test creates a single shared atomic pointer that multiple thread
+    // create weak pointers from. The threads then lock the weak pointers.
+    // Both threads clear all the pointers and check that the invariants
+    // hold.
+
+    using enum TrackedState;
+
+    TIBase::ResetStatesGuard const rsg{true};
+
+    std::atomic<int> destructionState{0};
+    // returns destructorRan and partialDestructorRan (in that order)
+    auto getDestructorState = [&]() -> std::pair<bool, bool> {
+        int const s = destructionState.load(std::memory_order_relaxed);
+        return {(s & 1) != 0, (s & 2) != 0};
+    };
+    auto setDestructorRan = [&]() -> void {
+        destructionState.fetch_or(1, std::memory_order_acq_rel);
+    };
+    auto setPartialDeleteRan = [&]() -> void {
+        destructionState.fetch_or(2, std::memory_order_acq_rel);
+    };
+    auto tracingCallback = [&](TrackedState cur, std::optional<TrackedState> next) {
+        using enum TrackedState;
+        auto [destructorRan, partialDeleteRan] = getDestructorState();
+        if (next == PartiallyDeleted)
+        {
+            EXPECT_FALSE(partialDeleteRan || destructorRan);
+            setPartialDeleteRan();
+        }
+        if (next == Deleted)
+        {
+            EXPECT_FALSE(destructorRan);
+            setDestructorRan();
+        }
+    };
+
+    constexpr int kLoopIters = 2 * 1024;
+    constexpr int kLockWeakLoopIters = 256;
+    constexpr int kNumThreads = 16;
+    std::vector<SharedIntrusive<TIBase>> toLock;
+    Barrier loopStartSyncPoint{kNumThreads};
+    Barrier postCreateToLockSyncPoint{kNumThreads};
+    Barrier postLockWeakLoopSyncPoint{kNumThreads};
+
+    // lockAndDestroy creates weak pointers from the strong pointer
+    // and runs a loop that locks the weak pointer. At the end of the loop
+    // all the pointers are destroyed all at once.
+    auto lockAndDestroy = [&](int threadId) {
+        for (int i = 0; i < kLoopIters; ++i)
+        {
+            // ------ Sync Point ------
+            loopStartSyncPoint.arriveAndWait();
+
+            // only thread 0 should reset the state
+            std::optional<TIBase::ResetStatesGuard> rsg;
+            if (threadId == 0)
+            {
+                // threadId 0 is the genesis thread. It creates the
+                // strong point to be locked by the other threads. This
+                // thread will also check that the destructor ran and
+                // clear the temporary variables.
+                rsg.emplace(false);
+                auto [destructorRan, partialDeleteRan] = getDestructorState();
+                EXPECT_TRUE(i == 0 || destructorRan);
+                destructionState.store(0, std::memory_order_release);
+
+                toLock.clear();
+                toLock.resize(kNumThreads);
+                auto strong = makeSharedIntrusive<TIBase>();
+                strong->tracingCallback = tracingCallback;
+                std::ranges::fill(toLock, strong);
+            }
+
+            // ------ Sync Point ------
+            postCreateToLockSyncPoint.arriveAndWait();
+
+            // Multiple threads all create a weak pointer from the same
+            // strong pointer
+            WeakIntrusive const weak{toLock[threadId]};
+            for (int wi = 0; wi < kLockWeakLoopIters; ++wi)
+            {
+                EXPECT_FALSE(weak.expired());
+                auto strong = weak.lock();
+                EXPECT_TRUE(strong);
+            }
+
+            // ------ Sync Point ------
+            postLockWeakLoopSyncPoint.arriveAndWait();
+
+            toLock[threadId].reset();
+        }
+    };
+    std::vector<std::thread> threads;
+    threads.reserve(kNumThreads);
+    for (int i = 0; i < kNumThreads; ++i)
+    {
+        threads.emplace_back(lockAndDestroy, i);
+    }
+    for (int i = 0; i < kNumThreads; ++i)
+    {
+        threads[i].join();
+    }
+}
+
+}  // namespace xrpl::tests
diff --git a/src/tests/libxrpl/basics/KeyCache.cpp b/src/tests/libxrpl/basics/KeyCache.cpp
new file mode 100644
index 0000000000..061264b11d
--- /dev/null
+++ b/src/tests/libxrpl/basics/KeyCache.cpp
@@ -0,0 +1,81 @@
+#include <xrpl/basics/TaggedCache.h>
+#include <xrpl/basics/TaggedCache.ipp>  // IWYU pragma: keep
+#include <xrpl/basics/chrono.h>
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/protocol/Protocol.h>
+
+#include <gtest/gtest.h>
+#include <helpers/TestSink.h>
+
+#include <string>
+
+namespace xrpl {
+
+class KeyCacheTest : public ::testing::Test
+{
+public:
+};
+
+TEST_F(KeyCacheTest, key_cache)
+{
+    using namespace std::chrono_literals;
+    TestStopwatch clock;
+    clock.set(0);
+
+    using Key = std::string;
+    using Cache = TaggedCache<Key, int, true>;
+
+    beast::Journal const j{TestSink::instance()};
+
+    // Insert an item, retrieve it, and age it so it gets purged.
+    {
+        Cache c("test", LedgerIndex(1), 2s, clock, j);
+
+        EXPECT_EQ(c.size(), 0);
+        EXPECT_TRUE(c.insert("one"));
+        EXPECT_FALSE(c.insert("one"));
+        EXPECT_EQ(c.size(), 1);
+        EXPECT_TRUE(c.touchIfExists("one"));
+        ++clock;
+        c.sweep();
+        EXPECT_EQ(c.size(), 1);
+        ++clock;
+        c.sweep();
+        EXPECT_EQ(c.size(), 0);
+        EXPECT_FALSE(c.touchIfExists("one"));
+    }
+
+    // Insert two items, have one expire
+    {
+        Cache c("test", LedgerIndex(2), 2s, clock, j);
+
+        EXPECT_TRUE(c.insert("one"));
+        EXPECT_EQ(c.size(), 1);
+        EXPECT_TRUE(c.insert("two"));
+        EXPECT_EQ(c.size(), 2);
+        ++clock;
+        c.sweep();
+        EXPECT_EQ(c.size(), 2);
+        EXPECT_TRUE(c.touchIfExists("two"));
+        ++clock;
+        c.sweep();
+        EXPECT_EQ(c.size(), 1);
+    }
+
+    // Insert three items (1 over limit), sweep
+    {
+        Cache c("test", LedgerIndex(2), 3s, clock, j);
+
+        EXPECT_TRUE(c.insert("one"));
+        ++clock;
+        EXPECT_TRUE(c.insert("two"));
+        ++clock;
+        EXPECT_TRUE(c.insert("three"));
+        ++clock;
+        EXPECT_EQ(c.size(), 3);
+        c.sweep();
+        EXPECT_LT(c.size(), 3);
+    }
+}
+
+}  // namespace xrpl
diff --git a/src/test/basics/Number_test.cpp b/src/tests/libxrpl/basics/Number.cpp
similarity index 74%
rename from src/test/basics/Number_test.cpp
rename to src/tests/libxrpl/basics/Number.cpp
index 5799ce7171..2b4d7be347 100644
--- a/src/test/basics/Number_test.cpp
+++ b/src/tests/libxrpl/basics/Number.cpp
@@ -1,5 +1,5 @@
 #include <xrpl/basics/Number.h>
-#include <xrpl/beast/unit_test/suite.h>
+
 #include <xrpl/protocol/IOUAmount.h>
 #include <xrpl/protocol/Issue.h>
 #include <xrpl/protocol/STAmount.h>
@@ -10,6 +10,8 @@
 #include <boost/multiprecision/cpp_dec_float.hpp>
 #include <boost/multiprecision/number.hpp>
 
+#include <gtest/gtest.h>
+
 #include <algorithm>
 #include <array>
 #include <cctype>
@@ -18,6 +20,7 @@
 #include <iomanip>
 #include <limits>
 #include <map>
+#include <ranges>
 #include <sstream>
 #include <stdexcept>
 #include <string>
@@ -27,84 +30,83 @@
 
 namespace xrpl {
 
-class Number_test : public beast::unit_test::Suite
+using BigInt = boost::multiprecision::cpp_int;
+using Dec = boost::multiprecision::cpp_dec_float_50;
+
+static std::string
+fmt(BigInt const& value)
 {
-    using BigInt = boost::multiprecision::cpp_int;
-
-    static std::string
-    fmt(BigInt const& value)
+    auto s = to_string(value);
+    std::string out;
+    int count = 0;
+    for (char const& ch : std::views::reverse(s))
     {
-        auto s = to_string(value);
-        std::string out;
-        int count = 0;
-        for (auto it = s.rbegin(); it != s.rend(); ++it)
-        {
-            if (count != 0 && count % 3 == 0 && (isdigit(*it) != 0))
-                out.insert(out.begin(), '_');
-            out.insert(out.begin(), *it);
-            ++count;
-        }
-        return out;
+        if (count != 0 && count % 3 == 0 && (isdigit(ch) != 0))
+            out.insert(out.begin(), '_');
+        out.insert(out.begin(), ch);
+        ++count;
+    }
+    return out;
+}
+
+template <class T = Dec>
+static T
+pow10(int n)
+{
+    if (n == 0)
+        return 1;
+    if (n == 1)
+        return 10;
+
+    if (n > 1)
+    {
+        auto r = pow10<T>(n / 2);
+        r *= r;
+        if (n % 2 != 0)
+            r *= 10;
+        return r;
     }
 
-    using dec = boost::multiprecision::cpp_dec_float_50;
+    T p = 1;
+    p /= pow10<T>(-n);
+    return p;
+}
 
-    template <class T = dec>
-    static T
-    pow10(int n)
+static std::string
+fmt(Dec const& value)
+{
+    std::ostringstream os;
+    os << std::setprecision(40) << value;
+    return os.str();
+}
+
+TEST(NumberTest, zero)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
-        if (n == 0)
-            return 1;
-        if (n == 1)
-            return 10;
-
-        if (n > 1)
-        {
-            auto r = pow10<T>(n / 2);
-            r *= r;
-            if (n % 2 != 0)
-                r *= 10;
-            return r;
-        }
-
-        // n < 0
-        T p = 1;
-        p /= pow10<T>(-n);
-        return p;
-    }
-
-    static std::string
-    fmt(dec const& v)
-    {
-        std::ostringstream os;
-        os << std::setprecision(40) << v;
-        return os.str();
-    }
-
-public:
-    void
-    testZero()
-    {
-        testcase << "zero " << to_string(Number::getMantissaScale());
+        NumberMantissaScaleGuard const sg(mantissaScale);
 
         for (Number const& z : {Number{0, 0}, Number{0}})
         {
-            BEAST_EXPECT(z.mantissa() == 0);
-            BEAST_EXPECT(z.exponent() == Number{}.exponent());
+            EXPECT_EQ(z.mantissa(), 0);
+            EXPECT_EQ(z.exponent(), Number{}.exponent());
 
-            BEAST_EXPECT((z + z) == z);
-            BEAST_EXPECT((z - z) == z);
-            BEAST_EXPECT(z == -z);
+            EXPECT_EQ((z + z), z);
+            EXPECT_EQ((z - z), z);
+            EXPECT_EQ(z, -z);
         }
     }
+}
 
-    void
-    testLimits()
+TEST(NumberTest, limits)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
+        NumberMantissaScaleGuard const sg(mantissaScale);
+
         auto const scale = Number::getMantissaScale();
         auto const minMantissa = Number::minMantissa();
 
-        testcase << "test_limits " << to_string(scale) << ", " << minMantissa;
         bool caught = false;
         try
         {
@@ -115,13 +117,13 @@ public:
         {
             caught = true;
         }
-        BEAST_EXPECT(caught);
+        EXPECT_TRUE(caught);
 
-        auto test = [this](auto const& x, auto const& y, int line) {
+        auto test = [](auto const& x, auto const& y, int line) {
             auto const result = x == y;
             std::stringstream ss;
             ss << x << " == " << y << " -> " << (result ? "true" : "false");
-            expect(result, ss.str(), __FILE__, line);
+            EXPECT_TRUE(result) << ss.str() << " (" << __FILE__ << ":" << line << ")";
         };
 
         test(
@@ -166,14 +168,17 @@ public:
         {
             caught = true;
         }
-        BEAST_EXPECT(caught);
+        EXPECT_TRUE(caught);
     }
+}
 
-    void
-    testAdd()
+TEST(NumberTest, add)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
+        NumberMantissaScaleGuard const sg(mantissaScale);
+
         auto const scale = Number::getMantissaScale();
-        testcase << "test_add " << to_string(scale);
 
         using Case = std::tuple<Number, Number, Number>;
         auto const cSmall = std::to_array<Case>(
@@ -281,13 +286,13 @@ public:
              Number{6, -1},
              Number{(Number::kLargestMantissa / 10) + 1, 1}},
         });
-        auto test = [this](auto const& c) {
+        auto test = [](auto const& c) {
             for (auto const& [x, y, z] : c)
             {
                 auto const result = x + y;
                 std::stringstream ss;
                 ss << x << " + " << y << " = " << result << ". Expected: " << z;
-                BEAST_EXPECTS(result == z, ss.str());
+                EXPECT_EQ(result, z) << ss.str();
             }
         };
         if (scale == MantissaRange::MantissaScale::Small)
@@ -317,15 +322,18 @@ public:
             {
                 caught = true;
             }
-            BEAST_EXPECT(caught);
+            EXPECT_TRUE(caught);
         }
     }
+}
 
-    void
-    testSub()
+TEST(NumberTest, sub)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
+        NumberMantissaScaleGuard const sg(mantissaScale);
+
         auto const scale = Number::getMantissaScale();
-        testcase << "test_sub " << to_string(scale);
 
         using Case = std::tuple<Number, Number, Number>;
         auto const cSmall = std::to_array<Case>(
@@ -387,13 +395,13 @@ public:
                  Number{Number::kLargestMantissa}},
                 {power(2, 63), Number{3, 0}, Number{Number::kLargestMantissa}},
             });
-        auto test = [this](auto const& c) {
+        auto test = [](auto const& c) {
             for (auto const& [x, y, z] : c)
             {
                 auto const result = x - y;
                 std::stringstream ss;
                 ss << x << " - " << y << " = " << result << ". Expected: " << z;
-                BEAST_EXPECTS(result == z, ss.str());
+                EXPECT_EQ(result, z) << ss.str();
             }
         };
         if (scale == MantissaRange::MantissaScale::Small)
@@ -405,31 +413,35 @@ public:
             test(cLarge);
         }
     }
+}
 
-    static std::uint64_t
-    getMaxInternalMantissa()
-    {
-        return (static_cast<std::uint64_t>(
-                    static_cast<std::int64_t>(power(10, Number::mantissaLog()))) *
-                10) -
-            1;
-    }
+static std::uint64_t
+getMaxInternalMantissa()
+{
+    return (static_cast<std::uint64_t>(
+                static_cast<std::int64_t>(power(10, Number::mantissaLog()))) *
+            10) -
+        1;
+}
 
-    void
-    testMul()
+TEST(NumberTest, mul)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
+        NumberMantissaScaleGuard const sg(mantissaScale);
+
         auto const scale = Number::getMantissaScale();
-        testcase << "test_mul " << to_string(scale);
 
         // Case: Factor 1, Factor 2, Expected product, Line number
         using Case = std::tuple<Number, Number, Number, int>;
-        auto test = [this](auto const& c) {
+        auto test = [](auto const& c) {
             for (auto const& [x, y, z, line] : c)
             {
                 auto const result = x * y;
                 std::stringstream ss;
-                ss << x << " * " << y << " = " << result << ". Expected: " << z;
-                BEAST_EXPECTS(result == z, ss.str() + " line: " + std::to_string(line));
+                ss << x << " * " << y << " = " << result << ". Expected: " << z
+                   << " line: " << line;
+                EXPECT_EQ(result, z) << ss.str();
             }
         };
         auto tests = [&](auto const& cSmall, auto const& cLarge) {
@@ -538,7 +550,6 @@ public:
             tests(cSmall, cLarge);
         }
         Number::setround(Number::RoundingMode::TowardsZero);
-        testcase << "test_mul " << to_string(Number::getMantissaScale()) << " towards_zero";
         {
             auto const cSmall = std::to_array<Case>(
                 {{Number{7}, Number{8}, Number{56}, __LINE__},
@@ -629,7 +640,6 @@ public:
             tests(cSmall, cLarge);
         }
         Number::setround(Number::RoundingMode::Downward);
-        testcase << "test_mul " << to_string(Number::getMantissaScale()) << " downward";
         {
             auto const cSmall = std::to_array<Case>(
                 {{Number{7}, Number{8}, Number{56}, __LINE__},
@@ -720,7 +730,6 @@ public:
             tests(cSmall, cLarge);
         }
         Number::setround(Number::RoundingMode::Upward);
-        testcase << "test_mul " << to_string(Number::getMantissaScale()) << " upward";
         {
             auto const cSmall = std::to_array<Case>(
                 {{Number{7}, Number{8}, Number{56}, __LINE__},
@@ -809,7 +818,6 @@ public:
                 });
             tests(cSmall, cLarge);
         }
-        testcase << "test_mul " << to_string(Number::getMantissaScale()) << " overflow";
         {
             bool caught = false;
             try
@@ -821,24 +829,27 @@ public:
             {
                 caught = true;
             }
-            BEAST_EXPECT(caught);
+            EXPECT_TRUE(caught);
         }
     }
+}
 
-    void
-    testDiv()
+TEST(NumberTest, div)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
+        NumberMantissaScaleGuard const sg(mantissaScale);
+
         auto const scale = Number::getMantissaScale();
-        testcase << "test_div " << to_string(scale);
 
         using Case = std::tuple<Number, Number, Number>;
-        auto test = [this](auto const& c) {
+        auto test = [](auto const& c) {
             for (auto const& [x, y, z] : c)
             {
                 auto const result = x / y;
                 std::stringstream ss;
                 ss << x << " / " << y << " = " << result << ". Expected: " << z;
-                BEAST_EXPECTS(result == z, ss.str());
+                EXPECT_EQ(result, z) << ss.str();
             }
         };
         auto const maxMantissa = Number::maxMantissa();
@@ -889,7 +900,6 @@ public:
                   Number{false, maxMantissa, -18, Number::Normalized{}}}});
             tests(cSmall, cLarge);
         }
-        testcase << "test_div " << to_string(Number::getMantissaScale()) << " towards_zero";
         Number::setround(Number::RoundingMode::TowardsZero);
         {
             auto const cSmall = std::to_array<Case>(
@@ -927,7 +937,6 @@ public:
                   Number{false, maxMantissa, -18, Number::Normalized{}}}});
             tests(cSmall, cLarge);
         }
-        testcase << "test_div " << to_string(Number::getMantissaScale()) << " downward";
         Number::setround(Number::RoundingMode::Downward);
         {
             auto const cSmall = std::to_array<Case>(
@@ -965,7 +974,6 @@ public:
                   Number{false, maxMantissa, -18, Number::Normalized{}}}});
             tests(cSmall, cLarge);
         }
-        testcase << "test_div " << to_string(Number::getMantissaScale()) << " upward";
         Number::setround(Number::RoundingMode::Upward);
         {
             auto const cSmall = std::to_array<Case>(
@@ -1003,7 +1011,6 @@ public:
                   Number{false, maxMantissa, -18, Number::Normalized{}}}});
             tests(cSmall, cLarge);
         }
-        testcase << "test_div " << to_string(Number::getMantissaScale()) << " overflow";
         bool caught = false;
         try
         {
@@ -1013,29 +1020,30 @@ public:
         {
             caught = true;
         }
-        BEAST_EXPECT(caught);
+        EXPECT_TRUE(caught);
     }
+}
 
-    void
-    testRoot()
+TEST(NumberTest, root)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
-        auto const scale = Number::getMantissaScale();
-        testcase << "test_root " << to_string(scale);
+        NumberMantissaScaleGuard const sg(mantissaScale);
 
         using Case = std::tuple<Number, unsigned, Number>;
-        auto test = [this](auto const& c) {
+        auto test = [](auto const& c) {
             for (auto const& [x, y, z] : c)
             {
                 auto const result = root(x, y);
                 std::stringstream ss;
                 ss << "root(" << x << ", " << y << ") = " << result << ". Expected: " << z;
-                BEAST_EXPECTS(result == z, ss.str());
+                EXPECT_EQ(result, z) << ss.str();
             }
         };
         /*
         auto tests = [&](auto const& cSmall, auto const& cLarge) {
             test(cSmall);
-            if (scale != MantissaRange::MantissaScale::Small)
+            if (scale != MantissaRange::mantissa_scale::small)
                 test(cLarge);
         };
         */
@@ -1081,7 +1089,7 @@ public:
         {
             caught = true;
         }
-        BEAST_EXPECT(caught);
+        EXPECT_TRUE(caught);
         caught = false;
         try
         {
@@ -1091,23 +1099,24 @@ public:
         {
             caught = true;
         }
-        BEAST_EXPECT(caught);
+        EXPECT_TRUE(caught);
     }
+}
 
-    void
-    testRoot2()
+TEST(NumberTest, root2)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
-        auto const scale = Number::getMantissaScale();
-        testcase << "test_root2 " << to_string(scale);
+        NumberMantissaScaleGuard const sg(mantissaScale);
 
-        auto test = [this](auto const& c) {
+        auto test = [](auto const& c) {
             for (auto const& x : c)
             {
                 auto const expected = root(x, 2);
                 auto const result = root2(x);
                 std::stringstream ss;
                 ss << "root2(" << x << ") = " << result << ". Expected: " << expected;
-                BEAST_EXPECTS(result == expected, ss.str());
+                EXPECT_EQ(result, expected) << ss.str();
             }
         };
 
@@ -1137,13 +1146,16 @@ public:
         {
             caught = true;
         }
-        BEAST_EXPECT(caught);
+        EXPECT_TRUE(caught);
     }
+}
 
-    void
-    testPower1()
+TEST(NumberTest, power1)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
-        testcase << "test_power1 " << to_string(Number::getMantissaScale());
+        NumberMantissaScaleGuard const sg(mantissaScale);
+
         using Case = std::tuple<Number, unsigned, Number>;
         Case const c[]{
             {Number{64}, 0, Number{1}},
@@ -1155,13 +1167,16 @@ public:
             {Number{64}, 11, Number{false, 7378697629483820646ULL, 1, Number::Normalized{}}},
             {Number{-64}, 11, Number{true, 7378697629483820646ULL, 1, Number::Normalized{}}}};
         for (auto const& [x, y, z] : c)
-            BEAST_EXPECT((power(x, y) == z));
+            EXPECT_EQ(power(x, y), z);
     }
+}
 
-    void
-    testPower2()
+TEST(NumberTest, power2)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
-        testcase << "test_power2 " << to_string(Number::getMantissaScale());
+        NumberMantissaScaleGuard const sg(mantissaScale);
+
         using Case = std::tuple<Number, unsigned, unsigned, Number>;
         Case const c[]{
             {Number{1}, 3, 7, Number{1}},
@@ -1171,7 +1186,7 @@ public:
             {Number{34}, 3, 3, Number{34}},
             {Number{4}, 3, 2, Number{8}}};
         for (auto const& [x, n, d, z] : c)
-            BEAST_EXPECT((power(x, n, d) == z));
+            EXPECT_EQ(power(x, n, d), z);
         bool caught = false;
         try
         {
@@ -1181,7 +1196,7 @@ public:
         {
             caught = true;
         }
-        BEAST_EXPECT(caught);
+        EXPECT_TRUE(caught);
         caught = false;
         try
         {
@@ -1191,7 +1206,7 @@ public:
         {
             caught = true;
         }
-        BEAST_EXPECT(caught);
+        EXPECT_TRUE(caught);
         caught = false;
         try
         {
@@ -1201,39 +1216,44 @@ public:
         {
             caught = true;
         }
-        BEAST_EXPECT(caught);
+        EXPECT_TRUE(caught);
     }
+}
 
-    void
-    testConversions()
+TEST(NumberTest, conversions)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
-        testcase << "testConversions " << to_string(Number::getMantissaScale());
+        NumberMantissaScaleGuard const sg(mantissaScale);
 
         IOUAmount const x{5, 6};
         Number const y = x;
-        BEAST_EXPECT((y == Number{5, 6}));
+        EXPECT_EQ(y, (Number{5, 6}));
         IOUAmount const z{y};
-        BEAST_EXPECT(x == z);
+        EXPECT_EQ(x, z);
         XRPAmount const xrp{500};
         STAmount const st = xrp;
         Number const n = st;
-        BEAST_EXPECT(XRPAmount{n} == xrp);
+        EXPECT_EQ(XRPAmount{n}, xrp);
         IOUAmount const x0{0, 0};
         Number const y0 = x0;
-        BEAST_EXPECT((y0 == Number{0}));
+        EXPECT_EQ(y0, Number{0});
         IOUAmount const z0{y0};
-        BEAST_EXPECT(x0 == z0);
+        EXPECT_EQ(x0, z0);
         XRPAmount const xrp0{0};
         Number const n0 = xrp0;
-        BEAST_EXPECT(n0 == Number{0});
-        XRPAmount const xrp1{n0};
-        BEAST_EXPECT(xrp1 == xrp0);
+        EXPECT_EQ(n0, Number{0});
+        XRPAmount const xrp1{n0};  // NOLINT misc-confusable-identifiers
+        EXPECT_EQ(xrp1, xrp0);
     }
+}
 
-    void
-    testToInteger()
+TEST(NumberTest, to_integer)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
-        testcase << "test_to_integer " << to_string(Number::getMantissaScale());
+        NumberMantissaScaleGuard const sg(mantissaScale);
+
         using Case = std::tuple<Number, std::int64_t>;
         SaveNumberRoundMode const save{Number::setround(Number::RoundingMode::ToNearest)};
         {
@@ -1269,11 +1289,11 @@ public:
             for (auto const& [x, y] : c)
             {
                 auto j = static_cast<std::int64_t>(x);
-                BEAST_EXPECT(j == y);
+                EXPECT_EQ(j, y);
             }
         }
         auto prevMode = Number::setround(Number::RoundingMode::TowardsZero);
-        BEAST_EXPECT(prevMode == Number::RoundingMode::ToNearest);
+        EXPECT_EQ(prevMode, Number::RoundingMode::ToNearest);
         {
             Case const c[]{
                 {Number{0}, 0},
@@ -1307,11 +1327,11 @@ public:
             for (auto const& [x, y] : c)
             {
                 auto j = static_cast<std::int64_t>(x);
-                BEAST_EXPECT(j == y);
+                EXPECT_EQ(j, y);
             }
         }
         prevMode = Number::setround(Number::RoundingMode::Downward);
-        BEAST_EXPECT(prevMode == Number::RoundingMode::TowardsZero);
+        EXPECT_EQ(prevMode, Number::RoundingMode::TowardsZero);
         {
             Case const c[]{
                 {Number{0}, 0},
@@ -1345,11 +1365,11 @@ public:
             for (auto const& [x, y] : c)
             {
                 auto j = static_cast<std::int64_t>(x);
-                BEAST_EXPECT(j == y);
+                EXPECT_EQ(j, y);
             }
         }
         prevMode = Number::setround(Number::RoundingMode::Upward);
-        BEAST_EXPECT(prevMode == Number::RoundingMode::Downward);
+        EXPECT_EQ(prevMode, Number::RoundingMode::Downward);
         {
             Case const c[]{
                 {Number{0}, 0},
@@ -1383,7 +1403,7 @@ public:
             for (auto const& [x, y] : c)
             {
                 auto j = static_cast<std::int64_t>(x);
-                BEAST_EXPECT(j == y);
+                EXPECT_EQ(j, y);
             }
         }
         bool caught = false;
@@ -1395,33 +1415,39 @@ public:
         {
             caught = true;
         }
-        BEAST_EXPECT(caught);
+        EXPECT_TRUE(caught);
     }
+}
 
-    void
-    testSquelch()
+TEST(NumberTest, squelch)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
-        testcase << "test_squelch " << to_string(Number::getMantissaScale());
+        NumberMantissaScaleGuard const sg(mantissaScale);
+
         Number const limit{1, -6};
-        BEAST_EXPECT((squelch(Number{2, -6}, limit) == Number{2, -6}));
-        BEAST_EXPECT((squelch(Number{1, -6}, limit) == Number{1, -6}));
-        BEAST_EXPECT((squelch(Number{9, -7}, limit) == Number{0}));
-        BEAST_EXPECT((squelch(Number{-2, -6}, limit) == Number{-2, -6}));
-        BEAST_EXPECT((squelch(Number{-1, -6}, limit) == Number{-1, -6}));
-        BEAST_EXPECT((squelch(Number{-9, -7}, limit) == Number{0}));
+        EXPECT_EQ(squelch(Number{2, -6}, limit), (Number{2, -6}));
+        EXPECT_EQ(squelch(Number{1, -6}, limit), (Number{1, -6}));
+        EXPECT_EQ(squelch(Number{9, -7}, limit), Number{0});
+        EXPECT_EQ(squelch(Number{-2, -6}, limit), (Number{-2, -6}));
+        EXPECT_EQ(squelch(Number{-1, -6}, limit), (Number{-1, -6}));
+        EXPECT_EQ(squelch(Number{-9, -7}, limit), Number{0});
     }
+}
 
-    void
-    testToString()
+TEST(NumberTest, to_string)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
-        auto const scale = Number::getMantissaScale();
-        testcase << "testToString " << to_string(scale);
+        NumberMantissaScaleGuard const sg(mantissaScale);
 
-        auto test = [this](Number const& n, std::string const& expected) {
+        auto const scale = Number::getMantissaScale();
+
+        auto test = [](Number const& n, std::string const& expected) {
             auto const result = to_string(n);
             std::stringstream ss;
             ss << "to_string(" << result << "). Expected: " << expected;
-            BEAST_EXPECTS(result == expected, ss.str());
+            EXPECT_EQ(result, expected) << ss.str();
         };
 
         test(Number(-2, 0), "-2");
@@ -1453,7 +1479,7 @@ public:
                     NumberRoundModeGuard const mg(Number::RoundingMode::TowardsZero);
 
                     auto const maxMantissa = Number::maxMantissa();
-                    BEAST_EXPECT(maxMantissa == 9'999'999'999'999'999);
+                    EXPECT_EQ(maxMantissa, (9'999'999'999'999'999));
                     test(
                         Number{false, (maxMantissa * 1000) + 999, -3, Number::Normalized()},
                         "9999999999999999");
@@ -1484,7 +1510,7 @@ public:
                     NumberRoundModeGuard const mg(Number::RoundingMode::TowardsZero);
 
                     auto const maxMantissa = Number::maxMantissa();
-                    BEAST_EXPECT(maxMantissa == 9'223'372'036'854'775'807ULL);
+                    EXPECT_EQ(maxMantissa, 9'223'372'036'854'775'807ULL);
                     test(
                         Number{false, maxMantissa, 0, Number::Normalized{}}, "9223372036854775807");
                     test(
@@ -1514,18 +1540,20 @@ public:
                     "-9223372036854775810");
                 break;
             default:
-                BEAST_EXPECT(false);
+                EXPECT_TRUE(false);
         }
     }
+}
 
-    void
-    testRelationals()
+TEST(NumberTest, relationals)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
-        testcase << "test_relationals " << to_string(Number::getMantissaScale());
+        NumberMantissaScaleGuard const sg(mantissaScale);
 
         {
-            auto test = [this](auto const& nums) {
-                BEAST_EXPECT(std::ranges::is_sorted(nums));
+            auto test = [](auto const& nums) {
+                EXPECT_TRUE(std::ranges::is_sorted(nums));
 
                 for (auto iter1 = nums.begin(); iter1 != nums.end(); ++iter1)
                 {
@@ -1541,32 +1569,32 @@ public:
                         // The ==/!= operators use a completely different code path than <, etc.
                         // This helps detect a breakage in one but not the other. It also helps
                         // verify that the values are being ordered correctly.
-                        BEAST_EXPECTS(smaller != larger, str + " (!=)");
-                        BEAST_EXPECTS(!(smaller == larger), str + " (==)");
+                        EXPECT_TRUE(smaller != larger) << str << " (!=)";
+                        EXPECT_FALSE(smaller == larger) << str << " (==)";
 
                         // true results using operator< and derived operators
-                        BEAST_EXPECTS(smaller < larger, str + " (<)");
-                        BEAST_EXPECTS(larger > smaller, str + " (>)");
-                        BEAST_EXPECTS(larger >= smaller, str + " (>=)");
-                        BEAST_EXPECTS(smaller <= larger, str + " (<=)");
+                        EXPECT_TRUE(smaller < larger) << str << " (<)";
+                        EXPECT_TRUE(larger > smaller) << str << " (>)";
+                        EXPECT_TRUE(larger >= smaller) << str << " (>=)";
+                        EXPECT_TRUE(smaller <= larger) << str << " (<=)";
 
                         // false results using operator< and derived operators
-                        BEAST_EXPECTS(!(larger < smaller), str + " (! <)");
-                        BEAST_EXPECTS(!(smaller > larger), str + " (! >)");
-                        BEAST_EXPECTS(!(smaller >= larger), str + " (! >=)");
-                        BEAST_EXPECTS(!(larger <= smaller), str + " (! <=)");
+                        EXPECT_FALSE(larger < smaller) << str << " (! <)";
+                        EXPECT_FALSE(smaller > larger) << str << " (! >)";
+                        EXPECT_FALSE(smaller >= larger) << str << " (! >=)";
+                        EXPECT_FALSE(larger <= smaller) << str << " (! <=)";
                     }
                 }
             };
 
-            auto const intNums = [this]() {
+            auto const intNums = []() {
                 // Inequality test cases are built from a list of sorted integers
                 auto const values =
                     std::to_array<int>({-100, -50, -20, -10, -1, 0, 1, 10, 20, 50, 100});
                 // Check this list is sorted before converting it to Numbers.
                 // That way if any of the other tests fail, we know it's because of code and not the
                 // source data.
-                BEAST_EXPECT(std::ranges::is_sorted(values));
+                EXPECT_TRUE(std::ranges::is_sorted(values));
 
                 std::vector<Number> result;
                 result.reserve(values.size());
@@ -1606,95 +1634,114 @@ public:
             for (auto const& [n, line] : c)
             {
                 auto const str = to_string(n);
+                auto const location =
+                    std::string{" ("} + __FILE__ + ":" + std::to_string(line) + ")";
 
                 // NOLINTBEGIN(misc-redundant-expression) Explicitly testing operators with
                 // equivalent values
-                expect(n == n, str + " ==", __FILE__, line);
-                expect(!(n != n), str + " !=", __FILE__, line);
+                EXPECT_TRUE(n == n) << str << " ==" << location;
+                EXPECT_FALSE(n != n) << str << " !=" << location;
 
-                expect(!(n < n), str + " < ", __FILE__, line);
-                expect(!(n > n), str + " >", __FILE__, line);
-                expect(n >= n, str + " >=", __FILE__, line);
-                expect(n <= n, str + " <=", __FILE__, line);
+                EXPECT_FALSE(n < n) << str << " <" << location;
+                EXPECT_FALSE(n > n) << str << " >" << location;
+                EXPECT_TRUE(n >= n) << str << " >=" << location;
+                EXPECT_TRUE(n <= n) << str << " <=" << location;
                 // NOLINTEND(misc-redundant-expression)
             }
         }
     }
+}
 
-    void
-    testStream()
+TEST(NumberTest, stream)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
-        testcase << "test_stream " << to_string(Number::getMantissaScale());
+        NumberMantissaScaleGuard const sg(mantissaScale);
+
         Number const x{100};
         std::ostringstream os;
         os << x;
-        BEAST_EXPECT(os.str() == to_string(x));
+        EXPECT_EQ((os.str()), (to_string(x)));
     }
+}
 
-    void
-    testIncDec()
+TEST(NumberTest, inc_dec)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
-        testcase << "test_inc_dec " << to_string(Number::getMantissaScale());
+        NumberMantissaScaleGuard const sg(mantissaScale);
+
         Number x{100};
         Number const y = +x;
-        BEAST_EXPECT(x == y);
-        BEAST_EXPECT(x++ == y);
-        BEAST_EXPECT(x == Number{101});
-        BEAST_EXPECT(x-- == Number{101});
-        BEAST_EXPECT(x == y);
+        EXPECT_EQ((x), (y));
+        EXPECT_EQ((x++), (y));
+        EXPECT_EQ((x), (Number{101}));
+        EXPECT_EQ((x--), (Number{101}));
+        EXPECT_EQ((x), (y));
     }
+}
 
-    void
-    testToStAmount()
+TEST(NumberTest, to_st_amount)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
+        NumberMantissaScaleGuard const sg(mantissaScale);
+
         Issue const issue;
         Number const n{7'518'783'80596, -5};
         SaveNumberRoundMode const save{Number::setround(Number::RoundingMode::ToNearest)};
         auto res2 = STAmount{issue, n};
-        BEAST_EXPECT(res2 == STAmount{7518784});
+        EXPECT_EQ((res2), (STAmount{7518784}));
 
         Number::setround(Number::RoundingMode::TowardsZero);
         res2 = STAmount{issue, n};
-        BEAST_EXPECT(res2 == STAmount{7518783});
+        EXPECT_EQ((res2), (STAmount{7518783}));
 
         Number::setround(Number::RoundingMode::Downward);
         res2 = STAmount{issue, n};
-        BEAST_EXPECT(res2 == STAmount{7518783});
+        EXPECT_EQ((res2), (STAmount{7518783}));
 
         Number::setround(Number::RoundingMode::Upward);
         res2 = STAmount{issue, n};
-        BEAST_EXPECT(res2 == STAmount{7518784});
+        EXPECT_EQ((res2), (STAmount{7518784}));
     }
+}
 
-    void
-    testTruncate()
+TEST(NumberTest, truncate)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
-        BEAST_EXPECT(Number(25, +1).truncate() == Number(250, 0));
-        BEAST_EXPECT(Number(25, 0).truncate() == Number(25, 0));
-        BEAST_EXPECT(Number(25, -1).truncate() == Number(2, 0));
-        BEAST_EXPECT(Number(25, -2).truncate() == Number(0, 0));
-        BEAST_EXPECT(Number(99, -2).truncate() == Number(0, 0));
+        NumberMantissaScaleGuard const sg(mantissaScale);
 
-        BEAST_EXPECT(Number(-25, +1).truncate() == Number(-250, 0));
-        BEAST_EXPECT(Number(-25, 0).truncate() == Number(-25, 0));
-        BEAST_EXPECT(Number(-25, -1).truncate() == Number(-2, 0));
-        BEAST_EXPECT(Number(-25, -2).truncate() == Number(0, 0));
-        BEAST_EXPECT(Number(-99, -2).truncate() == Number(0, 0));
+        EXPECT_EQ((Number(25, +1).truncate()), (Number(250, 0)));
+        EXPECT_EQ((Number(25, 0).truncate()), (Number(25, 0)));
+        EXPECT_EQ((Number(25, -1).truncate()), (Number(2, 0)));
+        EXPECT_EQ((Number(25, -2).truncate()), (Number(0, 0)));
+        EXPECT_EQ((Number(99, -2).truncate()), (Number(0, 0)));
 
-        BEAST_EXPECT(Number(0, 0).truncate() == Number(0, 0));
-        BEAST_EXPECT(Number(0, 30000).truncate() == Number(0, 0));
-        BEAST_EXPECT(Number(0, -30000).truncate() == Number(0, 0));
-        BEAST_EXPECT(Number(100, -30000).truncate() == Number(0, 0));
-        BEAST_EXPECT(Number(100, -30000).truncate() == Number(0, 0));
-        BEAST_EXPECT(Number(-100, -30000).truncate() == Number(0, 0));
-        BEAST_EXPECT(Number(-100, -30000).truncate() == Number(0, 0));
+        EXPECT_EQ((Number(-25, +1).truncate()), (Number(-250, 0)));
+        EXPECT_EQ((Number(-25, 0).truncate()), (Number(-25, 0)));
+        EXPECT_EQ((Number(-25, -1).truncate()), (Number(-2, 0)));
+        EXPECT_EQ((Number(-25, -2).truncate()), (Number(0, 0)));
+        EXPECT_EQ((Number(-99, -2).truncate()), (Number(0, 0)));
+
+        EXPECT_EQ((Number(0, 0).truncate()), (Number(0, 0)));
+        EXPECT_EQ((Number(0, 30000).truncate()), (Number(0, 0)));
+        EXPECT_EQ((Number(0, -30000).truncate()), (Number(0, 0)));
+        EXPECT_EQ((Number(100, -30000).truncate()), (Number(0, 0)));
+        EXPECT_EQ((Number(100, -30000).truncate()), (Number(0, 0)));
+        EXPECT_EQ((Number(-100, -30000).truncate()), (Number(0, 0)));
+        EXPECT_EQ((Number(-100, -30000).truncate()), (Number(0, 0)));
     }
+}
 
-    void
-    testRounding()
+TEST(NumberTest, rounding)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
+        NumberMantissaScaleGuard const sg(mantissaScale);
+
         // Test that rounding works as expected.
-        testcase("Rounding");
 
         using NumberRoundings = std::map<Number::RoundingMode, std::int64_t>;
 
@@ -1790,53 +1837,55 @@ public:
             {
                 NumberRoundModeGuard const g{mode};
                 auto const res = static_cast<std::int64_t>(num);
-                BEAST_EXPECTS(
-                    res == val,
-                    to_string(num) + " with mode " + std::to_string(static_cast<int>(mode)) +
-                        " expected " + std::to_string(val) + " got " + std::to_string(res));
+                EXPECT_EQ((res), (val)) << to_string(num) + " with mode " +
+                        std::to_string(static_cast<int>(mode)) + " expected " +
+                        std::to_string(val) + " got " + std::to_string(res);
             }
         }
     }
+}
 
-    void
-    testInt64()
+TEST(NumberTest, int64)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
+        NumberMantissaScaleGuard const sg(mantissaScale);
+
         auto const scale = Number::getMantissaScale();
-        testcase << "std::int64_t " << to_string(scale);
 
         // Control case
-        BEAST_EXPECT(Number::maxMantissa() > 10);
+        EXPECT_GT((Number::maxMantissa()), (10));
         Number const ten{10};
-        BEAST_EXPECT(ten.exponent() <= 0);
+        EXPECT_LE((ten.exponent()), (0));
 
         if (scale == MantissaRange::MantissaScale::Small)
         {
-            BEAST_EXPECT(std::numeric_limits<std::int64_t>::max() > kInitialXrp.drops());
-            BEAST_EXPECT(Number::maxMantissa() < kInitialXrp.drops());
+            EXPECT_GT((std::numeric_limits<std::int64_t>::max()), (kInitialXrp.drops()));
+            EXPECT_LT((Number::maxMantissa()), (kInitialXrp.drops()));
             Number const initalXrp{kInitialXrp};
-            BEAST_EXPECT(initalXrp.exponent() > 0);
+            EXPECT_GT((initalXrp.exponent()), (0));
 
             Number const maxInt64{Number::kLargestMantissa};
-            BEAST_EXPECT(maxInt64.exponent() > 0);
+            EXPECT_GT((maxInt64.exponent()), (0));
             // 85'070'591'730'234'615'865'843'651'857'942'052'864 - 38 digits
-            BEAST_EXPECT((power(maxInt64, 2) == Number{85'070'591'730'234'62, 22}));
+            EXPECT_EQ((power(maxInt64, 2)), (Number{85'070'591'730'234'62, 22}));
 
             Number const max = Number{false, Number::maxMantissa(), 0, Number::Normalized{}};
-            BEAST_EXPECT(max.exponent() <= 0);
+            EXPECT_LE(max.exponent(), 0);
             // 99'999'999'999'999'980'000'000'000'000'001 - 32 digits
-            BEAST_EXPECT((power(max, 2) == Number{99'999'999'999'999'98, 16}));
+            EXPECT_EQ(power(max, 2), (Number{99'999'999'999'999'98, 16}));
         }
         else
         {
-            BEAST_EXPECT(std::numeric_limits<std::int64_t>::max() > kInitialXrp.drops());
-            BEAST_EXPECT(Number::maxMantissa() > kInitialXrp.drops());
+            EXPECT_GT((std::numeric_limits<std::int64_t>::max()), (kInitialXrp.drops()));
+            EXPECT_GT((Number::maxMantissa()), (kInitialXrp.drops()));
             Number const initalXrp{kInitialXrp};
-            BEAST_EXPECT(initalXrp.exponent() <= 0);
+            EXPECT_LE((initalXrp.exponent()), (0));
 
             Number const maxInt64{Number::kLargestMantissa};
-            BEAST_EXPECT(maxInt64.exponent() <= 0);
+            EXPECT_LE((maxInt64.exponent()), (0));
             // 85'070'591'730'234'615'847'396'907'784'232'501'249 - 38 digits
-            BEAST_EXPECT((power(maxInt64, 2) == Number{85'070'591'730'234'615'85, 19}));
+            EXPECT_EQ((power(maxInt64, 2)), (Number{85'070'591'730'234'615'85, 19}));
 
             NumberRoundModeGuard const mg(Number::RoundingMode::TowardsZero);
 
@@ -1846,56 +1895,72 @@ public:
                 // Rounds down to fit under 2^63
                 Number const max = Number{false, maxInternalMantissa, 0, Number::Normalized{}};
                 // No alterations by the accessors
-                BEAST_EXPECT(max.mantissa() == maxInternalMantissa / 10);
-                BEAST_EXPECT(max.exponent() == 1);
+                EXPECT_EQ(max.mantissa(), maxInternalMantissa / 10);
+                EXPECT_EQ(max.exponent(), 1);
                 // 99'999'999'999'999'999'800'000'000'000'000'000'100 - also 38
                 // digits
-                BEAST_EXPECT(
-                    (power(max, 2) ==
-                     Number{false, (maxInternalMantissa / 10) - 1, 20, Number::Normalized{}}));
+                EXPECT_EQ(
+                    (power(max, 2)),
+                    (Number{false, (maxInternalMantissa / 10) - 1, 20, Number::Normalized{}}));
             }
 
             {
                 auto const maxMantissa = Number::maxMantissa();
                 Number const max = Number{false, maxMantissa, 0, Number::Normalized{}};
                 // No alterations by the accessors
-                BEAST_EXPECT(max.mantissa() == maxMantissa);
-                BEAST_EXPECT(max.exponent() == 0);
+                EXPECT_EQ(max.mantissa(), maxMantissa);
+                EXPECT_EQ(max.exponent(), 0);
                 // 85'070'591'730'234'615'847'396'907'784'232'501'249 - also 38
                 // digits
-                BEAST_EXPECT(
-                    (power(max, 2) ==
-                     Number{false, 85'070'591'730'234'615'84, 19, Number::Normalized{}}));
+                EXPECT_EQ(
+                    (power(max, 2)),
+                    (Number{false, 85'070'591'730'234'615'84, 19, Number::Normalized{}}));
             }
         }
     }
+}
 
-    void
-    testNormalizeToRange()
+class NumberTest
+{
+public:
+    template <Integral64 T>
+    [[nodiscard]]
+    static std::pair<T, int>
+    normalizeToRangeImpl(
+        Number const& n,
+        T minMantissa,
+        T maxMantissa,
+        MantissaRange::CuspRoundingFix fix)
     {
+        return Number::Access::normalizeToRangeImpl(n, minMantissa, maxMantissa, fix);
+    }
+};
+
+TEST(NumberTest, normalize_to_range)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
+    {
+        NumberMantissaScaleGuard const mg{mantissaScale};
+
         // Test edge-cases of normalizeToRange
         auto const scale = Number::getMantissaScale();
-        testcase << "normalizeToRange " << to_string(scale);
 
-        auto test = [this](
-                        Number const& n,
-                        auto const rangeMin,
-                        auto const rangeMax,
-                        auto const expectedMantissa,
-                        auto const expectedExponent,
-                        auto const line) {
-            auto const normalized =
-                n.normalizeToRangeImpl(rangeMin, rangeMax, MantissaRange::CuspRoundingFix::Enabled);
-            BEAST_EXPECTS(
-                normalized.first == expectedMantissa,
-                "Number " + to_string(n) + " scaled to " + std::to_string(rangeMax) +
-                    ". Expected mantissa:" + std::to_string(expectedMantissa) +
-                    ", got: " + std::to_string(normalized.first) + " @ " + std::to_string(line));
-            BEAST_EXPECTS(
-                normalized.second == expectedExponent,
-                "Number " + to_string(n) + " scaled to " + std::to_string(rangeMax) +
-                    ". Expected exponent:" + std::to_string(expectedExponent) +
-                    ", got: " + std::to_string(normalized.second) + " @ " + std::to_string(line));
+        auto test = [](Number const& n,
+                       auto const rangeMin,
+                       auto const rangeMax,
+                       auto const expectedMantissa,
+                       auto const expectedExponent,
+                       auto const line) {
+            auto const normalized = NumberTest::normalizeToRangeImpl(
+                n, rangeMin, rangeMax, MantissaRange::CuspRoundingFix::Enabled);
+            EXPECT_EQ(normalized.first, expectedMantissa)
+                << "Number " << n << " scaled to " << rangeMax
+                << ". Expected mantissa:" << expectedMantissa << ", got: " << normalized.first
+                << " @ " << line;
+            EXPECT_EQ(normalized.second, expectedExponent)
+                << "Number " << n << " scaled to " << rangeMax
+                << ". Expected exponent:" << expectedExponent << ", got: " << normalized.second
+                << " @ " << line;
         };
 
         std::int64_t constexpr kIRangeMin = 100;
@@ -2071,313 +2136,278 @@ public:
             }
         }
     }
+}
 
-    void
-    testUpwardRoundsDown()
-    {
-        auto const scale = Number::getMantissaScale();
-        {
-            testcase << "upward rounding produces a value below exact at kLargestMantissa cusp"
-                     << to_string(scale);
-
-            NumberRoundModeGuard const rg{Number::RoundingMode::Upward};
-
-            constexpr std::int64_t kAValue = 1'000'000'000'000'049'863LL;
-            constexpr std::int64_t kBValue = 9'223'372'036'854'315'903LL;
-
-            Number const a = kAValue;
-            Number const b = kBValue;
-            Number const product = a * b;
-
-            // Exact reference in BigInt.
-            BigInt const exactProduct = BigInt(kAValue) * BigInt(kBValue);
-
-            // What Number actually stored.
-            BigInt storedValue = BigInt(product.mantissa());
-            for (int i = 0; i < product.exponent(); ++i)
-                storedValue *= 10;
-
-            BigInt const signedDifference = storedValue - exactProduct;
-
-            log << "\n"
-                << "  a              = " << fmt(BigInt(kAValue)) << "\n"
-                << "  b              = " << fmt(BigInt(kBValue)) << "\n"
-                << "  exact a*b      = " << fmt(exactProduct) << "\n"
-                << "  stored         = " << fmt(storedValue) << "\n"
-                << "  stored - exact = " << fmt(signedDifference) << "\n"
-                << "  upward         = " << (signedDifference >= 0 ? "held" : "VIOLATED") << "\n"
-                << " stored.mantissa = " << product.mantissa() << "\n"
-                << " stored.exponent = " << product.exponent() << "\n";
-            log.flush();
-
-            switch (scale)
-            {
-                case MantissaRange::MantissaScale::Large:
-                    BEAST_EXPECT(signedDifference >= 0);
-                    BEAST_EXPECT(signedDifference < pow10<BigInt>(product.exponent()));
-                    BEAST_EXPECT(
-                        product.mantissa() == (std::numeric_limits<std::int64_t>::max() / 10) + 1);
-                    BEAST_EXPECT(product.exponent() == 19);
-                    break;
-
-                case MantissaRange::MantissaScale::LargeLegacy:
-                    BEAST_EXPECT(signedDifference < 0);
-                    BEAST_EXPECT(
-                        product.mantissa() ==
-                        (std::numeric_limits<std::int64_t>::max() / 100) * 100);
-                    BEAST_EXPECT(product.exponent() == 18);
-                    break;
-
-                case MantissaRange::MantissaScale::Small:
-                    // The seemingly weird rounding here is because
-                    // a & b are both normalized, and both round up when
-                    // being converted to Number, so you're really
-                    // getting 1_000_000_000_000_050 * 9_223_372_036_854_316
-                    BEAST_EXPECT(signedDifference >= 0);
-                    BEAST_EXPECT(
-                        product.mantissa() ==
-                        (std::numeric_limits<std::int64_t>::max() / 1000) + 3);
-                    BEAST_EXPECT(product.exponent() == 21);
-                    break;
-            }
-        }
-
-        {
-            /* Companion regression for the kMaxRep cusp behavior, but for
-             * `operator/=` on the cusp-fix-ENABLED `Large` scale.
-             *
-             * Before the dropped-remainder fix, `operator/=` with Upward
-             * rounding could return a value STRICTLY LESS than the exact quotient,
-             * violating Upward's directional invariant.
-             *
-             * Mechanism (fix-enabled path):
-             *   1. `operator/=` computes `numerator = nm * 10^17` and
-             *      `zm = numerator / dm` (integer division, truncates remainder).
-             *   2. If `remainder != 0`, the correction block runs:
-             *        zm *= 100000
-             *        correction = (remainder * 100000) / dm  // also truncates
-             *        zm += correction
-             *        ze -= 5
-             *      The truncation in `correction` discards a sub-1/100000 residual.
-             *   3. `normalize`'s shift loop reduces zm to fit, but the discarded
-             *      residual is BELOW the Guard's visibility, so the Guard sees fraction = 0.
-             *   4. Under Upward + positive, `round()` returns -1 (no round-up), and
-             *      the algorithm returns the truncated zm
-             */
-            testcase << "operator/= Upward on Large returns value < truth " << to_string(scale);
-
-            NumberRoundModeGuard const roundGuard{Number::RoundingMode::Upward};
-
-            constexpr std::int64_t aValue = 2LL;
-            constexpr std::int64_t bValue = 1'000'000'000'000'000'007LL;
-            // bValue = 10^18 + 7 (prime, in [minMantissa, kMaxRep]).
-
-            Number const a{aValue, 0};
-            Number const b{bValue, 0};
-            Number const quotient = a / b;
-
-            dec const exact = dec(aValue) / dec(bValue);
-            dec const stored = dec(quotient.mantissa()) * pow10(quotient.exponent());
-            dec const diff = stored - exact;
-
-            log << "\n"
-                << "  a                 = " << aValue << "\n"
-                << "  b                 = " << bValue << "\n"
-                << "  exact a/b         = " << fmt(exact) << "\n"
-                << "  stored a/b        = " << fmt(stored) << "\n"
-                << "  stored - exact    = " << fmt(diff)
-                << "    (negative => Upward gave value BELOW truth)\n"
-                << "  quotient.mantissa = " << quotient.mantissa() << "\n"
-                << "  quotient.exponent = " << quotient.exponent() << "\n";
-            log.flush();
-
-            // Upward invariant: stored >= exact. Bug: stored < exact.
-            switch (scale)
-            {
-                case MantissaRange::MantissaScale::Large:
-                    BEAST_EXPECT(stored >= exact);
-                    BEAST_EXPECT(diff < pow10(quotient.exponent()));
-                    break;
-
-                case MantissaRange::MantissaScale::LargeLegacy:
-                    BEAST_EXPECT(stored < exact);
-                    BEAST_EXPECT(diff >= -pow10(quotient.exponent()));
-                    break;
-
-                case MantissaRange::MantissaScale::Small:
-                    // Small mantissa doesn't have the correction for
-                    // dropped remainders
-                    BEAST_EXPECT(stored < exact);
-                    break;
-            }
-        }
-        {
-            /* Companion test case for Upward positive operator/=: Downward negative
-             */
-            testcase << "operator/= Downward on Large returns value < truth " << to_string(scale);
-
-            NumberRoundModeGuard const roundGuard{Number::RoundingMode::Downward};
-
-            constexpr std::int64_t aValue = -2LL;
-            constexpr std::int64_t bValue = 1'000'000'000'000'000'007LL;
-            // bValue = 10^18 + 7 (prime, in [minMantissa, kMaxRep]).
-
-            Number const a{aValue, 0};
-            Number const b{bValue, 0};
-            Number const quotient = a / b;
-
-            dec const exact = dec(aValue) / dec(bValue);
-            dec const stored = dec(quotient.mantissa()) * pow10(quotient.exponent());
-            dec const diff = stored - exact;
-
-            log << "\n"
-                << "  a                 = " << aValue << "\n"
-                << "  b                 = " << bValue << "\n"
-                << "  exact a/b         = " << fmt(exact) << "\n"
-                << "  stored a/b        = " << fmt(stored) << "\n"
-                << "  stored - exact    = " << fmt(diff)
-                << "    (positive => Downward gave value ABOVE truth)\n"
-                << "  quotient.mantissa = " << quotient.mantissa() << "\n"
-                << "  quotient.exponent = " << quotient.exponent() << "\n";
-            log.flush();
-
-            // invariant: stored <= exact. Bug: stored > exact.
-            switch (scale)
-            {
-                case MantissaRange::MantissaScale::Large:
-                    BEAST_EXPECT(stored <= exact);
-                    BEAST_EXPECT(diff > -pow10(quotient.exponent()));
-                    break;
-
-                case MantissaRange::MantissaScale::LargeLegacy:
-                    BEAST_EXPECT(stored > exact);
-                    BEAST_EXPECT(diff <= pow10(quotient.exponent()));
-                    break;
-
-                case MantissaRange::MantissaScale::Small:
-                    // Small mantissa doesn't have the correction for
-                    // dropped remainders
-                    BEAST_EXPECT(stored < exact);
-                    break;
-            }
-        }
-        {
-            /* Companion test case for Upward positive operator/=: ToNearest
-             *
-             * With ToNearest, if the dropped digits are exactly "5", then the mantissa will be
-             * rounded to even. The numbers below result in a value where the unrounded mantissa
-             * ends in an even digit, and "infinite precision" would drop
-             * "500000000000000000145...", but doNormalize only sees "5". Without the rounding fix,
-             * doNormalize rounds down to the even value. With the rounding fix, doNormalize knows
-             * there are more digits beyond "5", and so rounds _up_ to the odd value.
-             */
-            testcase << "operator/= ToNearest on Large returns value < truth " << to_string(scale);
-
-            NumberRoundModeGuard const roundGuard{Number::RoundingMode::ToNearest};
-
-            constexpr std::int64_t aValue = 1'269'917'268'816'087'809LL;
-            constexpr std::int64_t bValue = 3'458'525'013'821'685'511LL;
-            // bValue = 10^18 + 7 (prime, in [minMantissa, kMaxRep]).
-
-            Number const a{aValue, 0};
-            Number const b{bValue, 0};
-            Number const quotient = a / b;
-
-            dec const exact = dec(aValue) / dec(bValue);
-            dec const stored = dec(quotient.mantissa()) * pow10(quotient.exponent());
-            dec const diff = stored - exact;
-
-            log << "\n"
-                << "  a                 = " << aValue << "\n"
-                << "  b                 = " << bValue << "\n"
-                << "  exact a/b         = " << fmt(exact) << "\n"
-                << "  stored a/b        = " << fmt(stored) << "\n"
-                << "  stored - exact    = " << fmt(diff)
-                << "    (negative => ToNearest gave value BELOW truth)\n"
-                << "  quotient.mantissa = " << quotient.mantissa() << "\n"
-                << "  quotient.exponent = " << quotient.exponent() << "\n";
-            log.flush();
-
-            // invariant: stored >= exact. Bug: stored < exact.
-            switch (scale)
-            {
-                case MantissaRange::MantissaScale::Large:
-                    BEAST_EXPECT(stored >= exact);
-                    BEAST_EXPECT(diff < pow10(quotient.exponent()));
-                    break;
-
-                case MantissaRange::MantissaScale::LargeLegacy:
-                    BEAST_EXPECT(stored < exact);
-                    BEAST_EXPECT(diff >= -pow10(quotient.exponent()));
-                    break;
-
-                case MantissaRange::MantissaScale::Small:
-                    // Small mantissa doesn't have the correction for
-                    // dropped remainders
-                    BEAST_EXPECT(stored < exact);
-                    break;
-            }
-        }
-    }
-
-    void
-    run() override
-    {
-        for (auto const scale : MantissaRange::getAllScales())
-        {
-            NumberMantissaScaleGuard const sg(scale);
-            testZero();
-            testLimits();
-            testToString();
-            testAdd();
-            testSub();
-            testMul();
-            testDiv();
-            testRoot();
-            testRoot2();
-            testPower1();
-            testPower2();
-            testConversions();
-            testToInteger();
-            testSquelch();
-            testRelationals();
-            testStream();
-            testIncDec();
-            testToStAmount();
-            testTruncate();
-            testRounding();
-            testInt64();
-            testNormalizeToRange();
-
-            testUpwardRoundsDown();
-        }
-    }
-};
-
-class NumberPerf_test : public Number_test
+TEST(NumberTest, upward_rounding_produces_value_not_below_exact_at_k_max_rep_cusp)
 {
-    void
-    run() override
+    for (auto const mantissaScale : MantissaRange::getAllScales())
     {
-        // This suite will give the most accurate results when run
-        // single threaded, suppressing non-log output.
-        // "--unittest=NumberPerf --quiet --unittest-log"
-        using clock_type = std::chrono::steady_clock;
+        NumberMantissaScaleGuard const mg{mantissaScale};
+        NumberRoundModeGuard const rg{Number::RoundingMode::Upward};
 
-        int const limit = 100000;
-        auto const start = clock_type::now();
-        for (int i = 0; i < limit; ++i)
+        auto const scale = Number::getMantissaScale();
+
+        constexpr std::int64_t kAValue = 1'000'000'000'000'049'863LL;
+        constexpr std::int64_t kBValue = 9'223'372'036'854'315'903LL;
+
+        Number const a = kAValue;
+        Number const b = kBValue;
+        Number const product = a * b;
+
+        // Exact reference in BigInt.
+        BigInt const exactProduct = BigInt(kAValue) * BigInt(kBValue);
+
+        // What Number actually stored.
+        BigInt storedValue = BigInt(product.mantissa());
+        for (int i = 0; i < product.exponent(); ++i)
+            storedValue *= 10;
+
+        BigInt const signedDifference = storedValue - exactProduct;
+
+        auto const message = [&] {
+            std::ostringstream os;
+            os << "\n"
+               << "  a              = " << fmt(BigInt(kAValue)) << "\n"
+               << "  b              = " << fmt(BigInt(kBValue)) << "\n"
+               << "  exact a*b      = " << fmt(exactProduct) << "\n"
+               << "  stored         = " << fmt(storedValue) << "\n"
+               << "  stored - exact = " << fmt(signedDifference) << "\n"
+               << "  upward         = " << (signedDifference >= 0 ? "held" : "VIOLATED") << "\n"
+               << " stored.mantissa = " << product.mantissa() << "\n"
+               << " stored.exponent = " << product.exponent() << "\n";
+            return os.str();
+        };
+
+        switch (scale)
         {
-            Number_test::run();
+            case MantissaRange::MantissaScale::Large:
+                EXPECT_TRUE(signedDifference >= 0) << message();
+                EXPECT_TRUE(signedDifference < pow10<BigInt>(product.exponent())) << message();
+                EXPECT_EQ(product.mantissa(), (std::numeric_limits<std::int64_t>::max() / 10) + 1);
+                EXPECT_EQ(product.exponent(), 19);
+                break;
+
+            case MantissaRange::MantissaScale::LargeLegacy:
+                EXPECT_TRUE(signedDifference < 0) << message();
+                EXPECT_EQ(
+                    product.mantissa(), (std::numeric_limits<std::int64_t>::max() / 100) * 100);
+                EXPECT_EQ(product.exponent(), 18);
+                break;
+
+            case MantissaRange::MantissaScale::Small:
+                // The seemingly weird rounding here is because a & b are both
+                // normalized, and both round up when being converted to Number,
+                // so you're really getting
+                // 1_000_000_000_000_050 * 9_223_372_036_854_316.
+                EXPECT_TRUE(signedDifference >= 0) << message();
+                EXPECT_EQ(
+                    product.mantissa(), (std::numeric_limits<std::int64_t>::max() / 1000) + 3);
+                EXPECT_EQ(product.exponent(), 21);
+                break;
         }
-        auto const duration =
-            std::chrono::duration_cast<std::chrono::milliseconds>(clock_type::now() - start);
-
-        log << "Number test repeated " << limit << " times took " << duration << "\n";
     }
-};
+}
 
-BEAST_DEFINE_TESTSUITE(Number, basics, xrpl);
-BEAST_DEFINE_TESTSUITE_MANUAL(NumberPerf, tx, xrpl);
+/*
+ * Companion regression for the kMaxRep cusp behavior, but for `operator/=` on
+ * the cusp-fix-ENABLED `Large` scale.
+ *
+ * Before the dropped-remainder fix, `operator/=` with Upward rounding could
+ * return a value STRICTLY LESS than the exact quotient, violating Upward's
+ * directional invariant.
+ *
+ * Mechanism (fix-enabled path):
+ *   1. `operator/=` computes `numerator = nm * 10^17` and
+ *      `zm = numerator / dm` (integer division, truncates remainder).
+ *   2. If `remainder != 0`, the correction block runs:
+ *        zm *= 100000
+ *        correction = (remainder * 100000) / dm  // also truncates
+ *        zm += correction
+ *        ze -= 5
+ *      The truncation in `correction` discards a sub-1/100000 residual.
+ *   3. `normalize`'s shift loop reduces zm to fit, but the discarded residual
+ *      is BELOW the Guard's visibility, so the Guard sees fraction = 0.
+ *   4. Under Upward + positive, `round()` returns -1 (no round-up), and the
+ *      algorithm returns the truncated zm.
+ */
+TEST(NumberTest, upward_division_returns_value_not_below_exact_on_large_scale)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
+    {
+        NumberMantissaScaleGuard const mg{mantissaScale};
+        NumberRoundModeGuard const rg{Number::RoundingMode::Upward};
+
+        auto const scale = Number::getMantissaScale();
+
+        constexpr std::int64_t kAValue = 2LL;
+        constexpr std::int64_t kBValue = 1'000'000'000'000'000'007LL;
+        // kBValue = 10^18 + 7 (prime, in [minMantissa, kMaxRep]).
+
+        Number const a{kAValue, 0};
+        Number const b{kBValue, 0};
+        Number const quotient = a / b;
+
+        Dec const exact = Dec(kAValue) / Dec(kBValue);
+        Dec const stored = Dec(quotient.mantissa()) * pow10(quotient.exponent());
+        Dec const diff = stored - exact;
+
+        auto const message = [&] {
+            std::ostringstream os;
+            os << "\n"
+               << "  a                 = " << kAValue << "\n"
+               << "  b                 = " << kBValue << "\n"
+               << "  exact a/b         = " << fmt(exact) << "\n"
+               << "  stored a/b        = " << fmt(stored) << "\n"
+               << "  stored - exact    = " << fmt(diff)
+               << "    (negative => Upward gave value BELOW truth)\n"
+               << "  quotient.mantissa = " << quotient.mantissa() << "\n"
+               << "  quotient.exponent = " << quotient.exponent() << "\n";
+            return os.str();
+        };
+
+        // Upward invariant: stored >= exact. Bug: stored < exact.
+        switch (scale)
+        {
+            case MantissaRange::MantissaScale::Large:
+                EXPECT_TRUE(stored >= exact) << message();
+                EXPECT_TRUE(diff < pow10(quotient.exponent())) << message();
+                break;
+
+            case MantissaRange::MantissaScale::LargeLegacy:
+                EXPECT_TRUE(stored < exact) << message();
+                EXPECT_TRUE(diff >= -pow10(quotient.exponent())) << message();
+                break;
+
+            case MantissaRange::MantissaScale::Small:
+                // Small mantissa doesn't have the correction for dropped remainders.
+                EXPECT_TRUE(stored < exact) << message();
+                break;
+        }
+    }
+}
+
+// Companion test case for Upward positive operator/=: Downward negative.
+TEST(NumberTest, downward_division_returns_value_not_above_exact_on_large_scale)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
+    {
+        NumberMantissaScaleGuard const mg{mantissaScale};
+        NumberRoundModeGuard const rg{Number::RoundingMode::Downward};
+
+        auto const scale = Number::getMantissaScale();
+
+        constexpr std::int64_t kAValue = -2LL;
+        constexpr std::int64_t kBValue = 1'000'000'000'000'000'007LL;
+        // kBValue = 10^18 + 7 (prime, in [minMantissa, kMaxRep]).
+
+        Number const a{kAValue, 0};
+        Number const b{kBValue, 0};
+        Number const quotient = a / b;
+
+        Dec const exact = Dec(kAValue) / Dec(kBValue);
+        Dec const stored = Dec(quotient.mantissa()) * pow10(quotient.exponent());
+        Dec const diff = stored - exact;
+
+        auto const message = [&] {
+            std::ostringstream os;
+            os << "\n"
+               << "  a                 = " << kAValue << "\n"
+               << "  b                 = " << kBValue << "\n"
+               << "  exact a/b         = " << fmt(exact) << "\n"
+               << "  stored a/b        = " << fmt(stored) << "\n"
+               << "  stored - exact    = " << fmt(diff)
+               << "    (positive => Downward gave value ABOVE truth)\n"
+               << "  quotient.mantissa = " << quotient.mantissa() << "\n"
+               << "  quotient.exponent = " << quotient.exponent() << "\n";
+            return os.str();
+        };
+
+        // Downward invariant: stored <= exact. Bug: stored > exact.
+        switch (scale)
+        {
+            case MantissaRange::MantissaScale::Large:
+                EXPECT_TRUE(stored <= exact) << message();
+                EXPECT_TRUE(diff > -pow10(quotient.exponent())) << message();
+                break;
+
+            case MantissaRange::MantissaScale::LargeLegacy:
+                EXPECT_TRUE(stored > exact) << message();
+                EXPECT_TRUE(diff <= pow10(quotient.exponent())) << message();
+                break;
+
+            case MantissaRange::MantissaScale::Small:
+                // Small mantissa doesn't have the correction for dropped remainders.
+                EXPECT_TRUE(stored < exact) << message();
+                break;
+        }
+    }
+}
+
+/*
+ * Companion test case for Upward positive operator/=: ToNearest.
+ *
+ * With ToNearest, if the dropped digits are exactly "5", then the mantissa will
+ * be rounded to even. The numbers below result in a value where the unrounded
+ * mantissa ends in an even digit, and "infinite precision" would drop
+ * "500000000000000000145...", but doNormalize only sees "5". Without the
+ * rounding fix, doNormalize rounds down to the even value. With the rounding
+ * fix, doNormalize knows there are more digits beyond "5", and so rounds _up_
+ * to the odd value.
+ */
+TEST(NumberTest, to_nearest_division_uses_dropped_digits_on_large_scale)
+{
+    for (auto const mantissaScale : MantissaRange::getAllScales())
+    {
+        NumberMantissaScaleGuard const mg{mantissaScale};
+        NumberRoundModeGuard const rg{Number::RoundingMode::ToNearest};
+
+        auto const scale = Number::getMantissaScale();
+
+        constexpr std::int64_t kAValue = 1'269'917'268'816'087'809LL;
+        constexpr std::int64_t kBValue = 3'458'525'013'821'685'511LL;
+        // kBValue is prime and in [minMantissa, kMaxRep].
+
+        Number const a{kAValue, 0};
+        Number const b{kBValue, 0};
+        Number const quotient = a / b;
+
+        Dec const exact = Dec(kAValue) / Dec(kBValue);
+        Dec const stored = Dec(quotient.mantissa()) * pow10(quotient.exponent());
+        Dec const diff = stored - exact;
+
+        auto const message = [&] {
+            std::ostringstream os;
+            os << "\n"
+               << "  a                 = " << kAValue << "\n"
+               << "  b                 = " << kBValue << "\n"
+               << "  exact a/b         = " << fmt(exact) << "\n"
+               << "  stored a/b        = " << fmt(stored) << "\n"
+               << "  stored - exact    = " << fmt(diff)
+               << "    (negative => ToNearest gave value BELOW truth)\n"
+               << "  quotient.mantissa = " << quotient.mantissa() << "\n"
+               << "  quotient.exponent = " << quotient.exponent() << "\n";
+            return os.str();
+        };
+
+        // ToNearest should account for dropped digits beyond the visible "5".
+        switch (scale)
+        {
+            case MantissaRange::MantissaScale::Large:
+                EXPECT_TRUE(stored >= exact) << message();
+                EXPECT_TRUE(diff < pow10(quotient.exponent())) << message();
+                break;
+
+            case MantissaRange::MantissaScale::LargeLegacy:
+                EXPECT_TRUE(stored < exact) << message();
+                EXPECT_TRUE(diff >= -pow10(quotient.exponent())) << message();
+                break;
+
+            case MantissaRange::MantissaScale::Small:
+                // Small mantissa doesn't have the correction for dropped remainders.
+                EXPECT_TRUE(stored < exact) << message();
+                break;
+        }
+    }
+}
 
 }  // namespace xrpl
diff --git a/src/tests/libxrpl/basics/StringUtilities.cpp b/src/tests/libxrpl/basics/StringUtilities.cpp
new file mode 100644
index 0000000000..a10711abdb
--- /dev/null
+++ b/src/tests/libxrpl/basics/StringUtilities.cpp
@@ -0,0 +1,293 @@
+#include <xrpl/basics/StringUtilities.h>
+
+#include <xrpl/basics/Slice.h>
+#include <xrpl/basics/ToString.h>
+
+#include <gtest/gtest.h>
+
+#include <string>
+
+namespace xrpl {
+
+class StringUtilitiesTest : public ::testing::Test
+{
+public:
+    static void
+    testUnHexSuccess(std::string const& strIn, std::string const& strExpected)
+    {
+        auto rv = strUnHex(strIn);
+        EXPECT_TRUE(rv);
+
+        // NOLINTNEXTLINE(bugprone-unchecked-optional-access)
+        EXPECT_EQ(makeSlice(*rv), makeSlice(strExpected));
+    }
+
+    static void
+    testUnHexFailure(std::string const& strIn)
+    {
+        auto rv = strUnHex(strIn);
+        EXPECT_FALSE(rv);
+    }
+};
+
+TEST_F(StringUtilitiesTest, un_hex)
+{
+    testUnHexSuccess("526970706c6544", "RippleD");
+    testUnHexSuccess("A", "\n");
+    testUnHexSuccess("0A", "\n");
+    testUnHexSuccess("D0A", "\r\n");
+    testUnHexSuccess("0D0A", "\r\n");
+    testUnHexSuccess("200D0A", " \r\n");
+    testUnHexSuccess("282A2B2C2D2E2F29", "(*+,-./)");
+
+    // Check for things which contain some or only invalid characters
+    testUnHexFailure("123X");
+    testUnHexFailure("V");
+    testUnHexFailure("XRP");
+}
+
+TEST_F(StringUtilitiesTest, parse_url)
+{
+    // Expected passes.
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "scheme://"));
+        EXPECT_EQ(pUrl.scheme, "scheme");
+        EXPECT_TRUE(pUrl.username.empty());
+        EXPECT_TRUE(pUrl.password.empty());
+        EXPECT_TRUE(pUrl.domain.empty());
+        EXPECT_FALSE(pUrl.port);
+        // RFC 3986:
+        // > In general, a URI that uses the generic syntax for authority
+        //   with an empty path should be normalized to a path of "/".
+        // Do we want to normalize paths?
+        EXPECT_TRUE(pUrl.path.empty());
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "scheme:///"));
+        EXPECT_EQ(pUrl.scheme, "scheme");
+        EXPECT_TRUE(pUrl.username.empty());
+        EXPECT_TRUE(pUrl.password.empty());
+        EXPECT_TRUE(pUrl.domain.empty());
+        EXPECT_FALSE(pUrl.port);
+        EXPECT_EQ(pUrl.path, "/");
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "lower://domain"));
+        EXPECT_EQ(pUrl.scheme, "lower");
+        EXPECT_TRUE(pUrl.username.empty());
+        EXPECT_TRUE(pUrl.password.empty());
+        EXPECT_EQ(pUrl.domain, "domain");
+        EXPECT_FALSE(pUrl.port);
+        EXPECT_TRUE(pUrl.path.empty());
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "UPPER://domain:234/"));
+        EXPECT_EQ(pUrl.scheme, "upper");
+        EXPECT_TRUE(pUrl.username.empty());
+        EXPECT_TRUE(pUrl.password.empty());
+        EXPECT_EQ(pUrl.domain, "domain");
+        EXPECT_EQ(*pUrl.port, 234);  // NOLINT(bugprone-unchecked-optional-access)
+        EXPECT_EQ(pUrl.path, "/");
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "Mixed://domain/path"));
+        EXPECT_EQ(pUrl.scheme, "mixed");
+        EXPECT_TRUE(pUrl.username.empty());
+        EXPECT_TRUE(pUrl.password.empty());
+        EXPECT_EQ(pUrl.domain, "domain");
+        EXPECT_FALSE(pUrl.port);
+        EXPECT_EQ(pUrl.path, "/path");
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "scheme://[::1]:123/path"));
+        EXPECT_EQ(pUrl.scheme, "scheme");
+        EXPECT_TRUE(pUrl.username.empty());
+        EXPECT_TRUE(pUrl.password.empty());
+        EXPECT_EQ(pUrl.domain, "::1");
+        EXPECT_EQ(*pUrl.port, 123);  // NOLINT(bugprone-unchecked-optional-access)
+        EXPECT_EQ(pUrl.path, "/path");
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "scheme://user:pass@domain:123/abc:321"));
+        EXPECT_EQ(pUrl.scheme, "scheme");
+        EXPECT_EQ(pUrl.username, "user");
+        EXPECT_EQ(pUrl.password, "pass");
+        EXPECT_EQ(pUrl.domain, "domain");
+        EXPECT_EQ(*pUrl.port, 123);  // NOLINT(bugprone-unchecked-optional-access)
+        EXPECT_EQ(pUrl.path, "/abc:321");
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "scheme://user@domain:123/abc:321"));
+        EXPECT_EQ(pUrl.scheme, "scheme");
+        EXPECT_EQ(pUrl.username, "user");
+        EXPECT_TRUE(pUrl.password.empty());
+        EXPECT_EQ(pUrl.domain, "domain");
+        EXPECT_EQ(*pUrl.port, 123);  // NOLINT(bugprone-unchecked-optional-access)
+        EXPECT_EQ(pUrl.path, "/abc:321");
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "scheme://:pass@domain:123/abc:321"));
+        EXPECT_EQ(pUrl.scheme, "scheme");
+        EXPECT_TRUE(pUrl.username.empty());
+        EXPECT_EQ(pUrl.password, "pass");
+        EXPECT_EQ(pUrl.domain, "domain");
+        EXPECT_EQ(*pUrl.port, 123);  // NOLINT(bugprone-unchecked-optional-access)
+        EXPECT_EQ(pUrl.path, "/abc:321");
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "scheme://domain:123/abc:321"));
+        EXPECT_EQ(pUrl.scheme, "scheme");
+        EXPECT_TRUE(pUrl.username.empty());
+        EXPECT_TRUE(pUrl.password.empty());
+        EXPECT_EQ(pUrl.domain, "domain");
+        EXPECT_EQ(*pUrl.port, 123);  // NOLINT(bugprone-unchecked-optional-access)
+        EXPECT_EQ(pUrl.path, "/abc:321");
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "scheme://user:pass@domain/abc:321"));
+        EXPECT_EQ(pUrl.scheme, "scheme");
+        EXPECT_EQ(pUrl.username, "user");
+        EXPECT_EQ(pUrl.password, "pass");
+        EXPECT_EQ(pUrl.domain, "domain");
+        EXPECT_FALSE(pUrl.port);
+        EXPECT_EQ(pUrl.path, "/abc:321");
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "scheme://user@domain/abc:321"));
+        EXPECT_EQ(pUrl.scheme, "scheme");
+        EXPECT_EQ(pUrl.username, "user");
+        EXPECT_TRUE(pUrl.password.empty());
+        EXPECT_EQ(pUrl.domain, "domain");
+        EXPECT_FALSE(pUrl.port);
+        EXPECT_EQ(pUrl.path, "/abc:321");
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "scheme://:pass@domain/abc:321"));
+        EXPECT_EQ(pUrl.scheme, "scheme");
+        EXPECT_TRUE(pUrl.username.empty());
+        EXPECT_EQ(pUrl.password, "pass");
+        EXPECT_EQ(pUrl.domain, "domain");
+        EXPECT_FALSE(pUrl.port);
+        EXPECT_EQ(pUrl.path, "/abc:321");
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "scheme://domain/abc:321"));
+        EXPECT_EQ(pUrl.scheme, "scheme");
+        EXPECT_TRUE(pUrl.username.empty());
+        EXPECT_TRUE(pUrl.password.empty());
+        EXPECT_EQ(pUrl.domain, "domain");
+        EXPECT_FALSE(pUrl.port);
+        EXPECT_EQ(pUrl.path, "/abc:321");
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "scheme:///path/to/file"));
+        EXPECT_EQ(pUrl.scheme, "scheme");
+        EXPECT_TRUE(pUrl.username.empty());
+        EXPECT_TRUE(pUrl.password.empty());
+        EXPECT_TRUE(pUrl.domain.empty());
+        EXPECT_FALSE(pUrl.port);
+        EXPECT_EQ(pUrl.path, "/path/to/file");
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "scheme://user:pass@domain/path/with/an@sign"));
+        EXPECT_EQ(pUrl.scheme, "scheme");
+        EXPECT_EQ(pUrl.username, "user");
+        EXPECT_EQ(pUrl.password, "pass");
+        EXPECT_EQ(pUrl.domain, "domain");
+        EXPECT_FALSE(pUrl.port);
+        EXPECT_EQ(pUrl.path, "/path/with/an@sign");
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "scheme://domain/path/with/an@sign"));
+        EXPECT_EQ(pUrl.scheme, "scheme");
+        EXPECT_TRUE(pUrl.username.empty());
+        EXPECT_TRUE(pUrl.password.empty());
+        EXPECT_EQ(pUrl.domain, "domain");
+        EXPECT_FALSE(pUrl.port);
+        EXPECT_EQ(pUrl.path, "/path/with/an@sign");
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "scheme://:999/"));
+        EXPECT_EQ(pUrl.scheme, "scheme");
+        EXPECT_TRUE(pUrl.username.empty());
+        EXPECT_TRUE(pUrl.password.empty());
+        EXPECT_EQ(pUrl.domain, ":999");
+        EXPECT_FALSE(pUrl.port);
+        EXPECT_EQ(pUrl.path, "/");
+    }
+
+    {
+        ParsedUrl pUrl;
+        EXPECT_TRUE(parseUrl(pUrl, "http://::1:1234/validators"));
+        EXPECT_EQ(pUrl.scheme, "http");
+        EXPECT_TRUE(pUrl.username.empty());
+        EXPECT_TRUE(pUrl.password.empty());
+        EXPECT_EQ(pUrl.domain, "::0.1.18.52");
+        EXPECT_FALSE(pUrl.port);
+        EXPECT_EQ(pUrl.path, "/validators");
+    }
+
+    // Expected fails.
+    {
+        ParsedUrl pUrl;
+        EXPECT_FALSE(parseUrl(pUrl, ""));
+        EXPECT_FALSE(parseUrl(pUrl, "nonsense"));
+        EXPECT_FALSE(parseUrl(pUrl, "://"));
+        EXPECT_FALSE(parseUrl(pUrl, ":///"));
+        EXPECT_FALSE(parseUrl(pUrl, "scheme://user:pass@domain:65536/abc:321"));
+        EXPECT_FALSE(parseUrl(pUrl, "UPPER://domain:23498765/"));
+        EXPECT_FALSE(parseUrl(pUrl, "UPPER://domain:0/"));
+        EXPECT_FALSE(parseUrl(pUrl, "UPPER://domain:+7/"));
+        EXPECT_FALSE(parseUrl(pUrl, "UPPER://domain:-7234/"));
+        EXPECT_FALSE(parseUrl(pUrl, "UPPER://domain:@#$56!/"));
+    }
+
+    {
+        std::string const strUrl("s://" + std::string(8192, ':'));
+        ParsedUrl pUrl;
+        EXPECT_FALSE(parseUrl(pUrl, strUrl));
+    }
+}
+
+TEST_F(StringUtilitiesTest, to_string)
+{
+    auto result = to_string("hello");
+    EXPECT_EQ(result, "hello");
+}
+
+}  // namespace xrpl
diff --git a/src/tests/libxrpl/basics/TaggedCache.cpp b/src/tests/libxrpl/basics/TaggedCache.cpp
new file mode 100644
index 0000000000..c8ccc415ad
--- /dev/null
+++ b/src/tests/libxrpl/basics/TaggedCache.cpp
@@ -0,0 +1,246 @@
+#include <xrpl/basics/TaggedCache.h>
+
+#include <xrpl/basics/IntrusivePointer.h>
+#include <xrpl/basics/IntrusiveRefCounts.h>
+#include <xrpl/basics/TaggedCache.ipp>  // IWYU pragma: keep
+#include <xrpl/basics/chrono.h>
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/protocol/Protocol.h>
+
+#include <gtest/gtest.h>
+#include <helpers/TestSink.h>
+
+#include <memory>
+#include <string>
+#include <utility>
+
+namespace xrpl {
+
+/*
+I guess you can put some items in, make sure they're still there. Let some
+time pass, make sure they're gone. Keep a strong pointer to one of them, make
+sure you can still find it even after time passes. Create two objects with
+the same key, canonicalize them both and make sure you get the same object.
+Put an object in but keep a strong pointer to it, advance the clock a lot,
+then canonicalize a new object with the same key, make sure you get the
+original object.
+*/
+
+TEST(TaggedCacheTest, tagged_cache)
+{
+    using namespace std::chrono_literals;
+    beast::Journal const journal{TestSink::instance()};
+
+    TestStopwatch clock;
+    clock.set(0);
+
+    using Key = LedgerIndex;
+    using Value = std::string;
+    using Cache = TaggedCache<Key, Value>;
+
+    Cache c("test", 1, 1s, clock, journal);
+
+    // Insert an item, retrieve it, and age it so it gets purged.
+    {
+        EXPECT_EQ(c.getCacheSize(), 0);
+        EXPECT_EQ(c.getTrackSize(), 0);
+        EXPECT_FALSE(c.insert(1, "one"));
+        EXPECT_EQ(c.getCacheSize(), 1);
+        EXPECT_EQ(c.getTrackSize(), 1);
+
+        {
+            std::string s;
+            EXPECT_TRUE(c.retrieve(1, s));
+            EXPECT_EQ(s, "one");
+        }
+
+        ++clock;
+        c.sweep();
+        EXPECT_EQ(c.getCacheSize(), 0);
+        EXPECT_EQ(c.getTrackSize(), 0);
+    }
+
+    // Insert an item, maintain a strong pointer, age it, and
+    // verify that the entry still exists.
+    {
+        EXPECT_FALSE(c.insert(2, "two"));
+        EXPECT_EQ(c.getCacheSize(), 1);
+        EXPECT_EQ(c.getTrackSize(), 1);
+
+        {
+            auto p = c.fetch(2);
+            EXPECT_NE(p, nullptr);
+            ++clock;
+            c.sweep();
+            EXPECT_EQ(c.getCacheSize(), 0);
+            EXPECT_EQ(c.getTrackSize(), 1);
+        }
+
+        // Make sure its gone now that our reference is gone
+        ++clock;
+        c.sweep();
+        EXPECT_EQ(c.getCacheSize(), 0);
+        EXPECT_EQ(c.getTrackSize(), 0);
+    }
+
+    // Insert the same key/value pair and make sure we get the same result
+    {
+        EXPECT_FALSE(c.insert(3, "three"));
+
+        {
+            auto const p1 = c.fetch(3);
+            auto p2 = std::make_shared<Value>("three");
+            c.canonicalizeReplaceClient(3, p2);
+            EXPECT_EQ(p1.get(), p2.get());
+        }
+        ++clock;
+        c.sweep();
+        EXPECT_EQ(c.getCacheSize(), 0);
+        EXPECT_EQ(c.getTrackSize(), 0);
+    }
+
+    // Put an object in but keep a strong pointer to it, advance the clock a
+    // lot, then canonicalize a new object with the same key, make sure you
+    // get the original object.
+    {
+        // Put an object in
+        EXPECT_FALSE(c.insert(4, "four"));
+        EXPECT_EQ(c.getCacheSize(), 1);
+        EXPECT_EQ(c.getTrackSize(), 1);
+
+        {
+            // Keep a strong pointer to it
+            auto const p1 = c.fetch(4);
+            EXPECT_NE(p1, nullptr);
+            EXPECT_EQ(c.getCacheSize(), 1);
+            EXPECT_EQ(c.getTrackSize(), 1);
+            // Advance the clock a lot
+            ++clock;
+            c.sweep();
+            EXPECT_EQ(c.getCacheSize(), 0);
+            EXPECT_EQ(c.getTrackSize(), 1);
+            // Canonicalize a new object with the same key
+            auto p2 = std::make_shared<std::string>("four");
+            EXPECT_TRUE(c.canonicalizeReplaceClient(4, p2));
+            EXPECT_EQ(c.getCacheSize(), 1);
+            EXPECT_EQ(c.getTrackSize(), 1);
+            // Make sure we get the original object
+            EXPECT_EQ(p1.get(), p2.get());
+        }
+
+        ++clock;
+        c.sweep();
+        EXPECT_EQ(c.getCacheSize(), 0);
+        EXPECT_EQ(c.getTrackSize(), 0);
+    }
+
+    {
+        EXPECT_FALSE(c.insert(5, "five"));
+        EXPECT_EQ(c.getCacheSize(), 1);
+        EXPECT_EQ(c.size(), 1);
+
+        {
+            auto const p1 = c.fetch(5);
+            EXPECT_NE(p1, nullptr);
+            EXPECT_EQ(c.getCacheSize(), 1);
+            EXPECT_EQ(c.size(), 1);
+
+            // Advance the clock a lot
+            ++clock;
+            c.sweep();
+            EXPECT_EQ(c.getCacheSize(), 0);
+            EXPECT_EQ(c.size(), 1);
+
+            auto p2 = std::make_shared<std::string>("five_2");
+            EXPECT_TRUE(c.canonicalizeReplaceCache(5, p2));
+            EXPECT_EQ(c.getCacheSize(), 1);
+            EXPECT_EQ(c.size(), 1);
+            // Make sure the caller's original pointer is unchanged
+            EXPECT_NE(p1.get(), p2.get());
+            EXPECT_EQ(*p2, "five_2");
+
+            auto const p3 = c.fetch(5);
+            EXPECT_NE(p3, nullptr);
+            EXPECT_EQ(p3.get(), p2.get());
+            EXPECT_NE(p3.get(), p1.get());
+        }
+
+        ++clock;
+        c.sweep();
+        EXPECT_EQ(c.getCacheSize(), 0);
+        EXPECT_EQ(c.size(), 0);
+    }
+
+    {
+        struct MyRefCountObject : IntrusiveRefCounts
+        {
+            std::string data;
+
+            // Needed to support weak intrusive pointers
+            virtual void
+            partialDestructor()
+            {
+            }
+
+            MyRefCountObject() = default;
+            explicit MyRefCountObject(std::string data) : data(std::move(data))
+            {
+            }
+
+            bool
+            operator==(std::string const& other) const
+            {
+                return data == other;
+            }
+        };
+
+        using IntrPtrCache = TaggedCache<
+            Key,
+            MyRefCountObject,
+            /*IsKeyCache*/ false,
+            intr_ptr::SharedWeakUnionPtr<MyRefCountObject>,
+            intr_ptr::SharedPtr<MyRefCountObject>>;
+
+        IntrPtrCache intrPtrCache("IntrPtrTest", 1, 1s, clock, journal);
+
+        intrPtrCache.canonicalizeReplaceCache(1, intr_ptr::makeShared<MyRefCountObject>("one"));
+        EXPECT_EQ(intrPtrCache.getCacheSize(), 1);
+        EXPECT_EQ(intrPtrCache.size(), 1);
+
+        {
+            {
+                intrPtrCache.canonicalizeReplaceCache(
+                    1, intr_ptr::makeShared<MyRefCountObject>("one_replaced"));
+
+                auto p = intrPtrCache.fetch(1);
+                EXPECT_EQ(*p, "one_replaced");
+
+                // Advance the clock a lot
+                ++clock;
+                intrPtrCache.sweep();
+                EXPECT_EQ(intrPtrCache.getCacheSize(), 0);
+                EXPECT_EQ(intrPtrCache.size(), 1);
+
+                intrPtrCache.canonicalizeReplaceCache(
+                    1, intr_ptr::makeShared<MyRefCountObject>("one_replaced_2"));
+
+                auto p2 = intrPtrCache.fetch(1);
+                EXPECT_EQ(*p2, "one_replaced_2");
+
+                intrPtrCache.del(1, true);
+            }
+
+            intrPtrCache.canonicalizeReplaceCache(
+                1, intr_ptr::makeShared<MyRefCountObject>("one_replaced_3"));
+            auto p3 = intrPtrCache.fetch(1);
+            EXPECT_EQ(*p3, "one_replaced_3");
+        }
+
+        ++clock;
+        intrPtrCache.sweep();
+        EXPECT_EQ(intrPtrCache.getCacheSize(), 0);
+        EXPECT_EQ(intrPtrCache.size(), 0);
+    }
+}
+
+}  // namespace xrpl
diff --git a/src/tests/libxrpl/basics/Units.cpp b/src/tests/libxrpl/basics/Units.cpp
new file mode 100644
index 0000000000..1cf7024fe0
--- /dev/null
+++ b/src/tests/libxrpl/basics/Units.cpp
@@ -0,0 +1,328 @@
+#include <xrpl/protocol/Units.h>
+
+#include <xrpl/beast/utility/Zero.h>
+#include <xrpl/json/json_value.h>
+#include <xrpl/protocol/SystemParameters.h>
+#include <xrpl/protocol/XRPAmount.h>
+
+#include <gtest/gtest.h>
+
+#include <cstdint>
+#include <limits>
+#include <type_traits>
+
+namespace xrpl::test {
+
+TEST(UnitsTest, types)
+{
+    using FeeLevel32 = FeeLevel<std::uint32_t>;
+
+    {
+        XRPAmount const x{100};
+        EXPECT_EQ(x.drops(), 100);
+        EXPECT_TRUE((std::is_same_v<decltype(x)::unit_type, unit::dropTag>));
+        auto y = 4u * x;
+        EXPECT_EQ(y.value(), 400);
+        EXPECT_TRUE((std::is_same_v<decltype(y)::unit_type, unit::dropTag>));
+
+        auto z = 4 * y;
+        EXPECT_EQ(z.value(), 1600);
+        EXPECT_TRUE((std::is_same_v<decltype(z)::unit_type, unit::dropTag>));
+
+        FeeLevel32 const f{10};
+        FeeLevel32 const baseFee{100};
+
+        auto drops = mulDiv(baseFee, x, f);
+
+        EXPECT_TRUE(drops);
+        EXPECT_EQ(drops.value(), 1000);  // NOLINT(bugprone-unchecked-optional-access)
+        EXPECT_TRUE(
+            (std::is_same_v<std::remove_reference_t<decltype(*drops)>::unit_type, unit::dropTag>));
+
+        EXPECT_TRUE((std::is_same_v<std::remove_reference_t<decltype(*drops)>, XRPAmount>));
+    }
+    {
+        XRPAmount const x{100};
+        EXPECT_EQ(x.value(), 100);
+        EXPECT_TRUE((std::is_same_v<decltype(x)::unit_type, unit::dropTag>));
+        auto y = 4u * x;
+        EXPECT_EQ(y.value(), 400);
+        EXPECT_TRUE((std::is_same_v<decltype(y)::unit_type, unit::dropTag>));
+
+        FeeLevel64 const f{10};
+        FeeLevel64 const baseFee{100};
+
+        auto drops = mulDiv(baseFee, x, f);
+
+        EXPECT_TRUE(drops);
+        EXPECT_EQ(drops.value(), 1000);  // NOLINT(bugprone-unchecked-optional-access)
+        EXPECT_TRUE(
+            (std::is_same_v<std::remove_reference_t<decltype(*drops)>::unit_type, unit::dropTag>));
+        EXPECT_TRUE((std::is_same_v<std::remove_reference_t<decltype(*drops)>, XRPAmount>));
+    }
+    {
+        FeeLevel64 const x{1024};
+        EXPECT_EQ(x.value(), 1024);
+        EXPECT_TRUE((std::is_same_v<decltype(x)::unit_type, unit::feelevelTag>));
+        std::uint64_t const m = 4;
+        auto y = m * x;
+        EXPECT_EQ(y.value(), 4096);
+        EXPECT_TRUE((std::is_same_v<decltype(y)::unit_type, unit::feelevelTag>));
+
+        XRPAmount const basefee{10};
+        FeeLevel64 const referencefee{256};
+
+        auto drops = mulDiv(x, basefee, referencefee);
+
+        EXPECT_TRUE(drops);
+        EXPECT_EQ(drops.value(), 40);  // NOLINT(bugprone-unchecked-optional-access)
+        EXPECT_TRUE(
+            (std::is_same_v<std::remove_reference_t<decltype(*drops)>::unit_type, unit::dropTag>));
+        EXPECT_TRUE((std::is_same_v<std::remove_reference_t<decltype(*drops)>, XRPAmount>));
+    }
+}
+
+TEST(UnitsTest, json)
+{
+    // Json value functionality
+    using FeeLevel32 = FeeLevel<std::uint32_t>;
+
+    {
+        FeeLevel32 const x{std::numeric_limits<std::uint32_t>::max()};
+        auto y = x.jsonClipped();
+        EXPECT_EQ(y.type(), json::ValueType::UInt);
+        EXPECT_EQ(y, json::Value{x.fee()});
+    }
+
+    {
+        FeeLevel32 const x{std::numeric_limits<std::uint32_t>::min()};
+        auto y = x.jsonClipped();
+        EXPECT_EQ(y.type(), json::ValueType::UInt);
+        EXPECT_EQ(y, json::Value{x.fee()});
+    }
+
+    {
+        FeeLevel64 const x{std::numeric_limits<std::uint64_t>::max()};
+        auto y = x.jsonClipped();
+        EXPECT_EQ(y.type(), json::ValueType::UInt);
+        EXPECT_EQ(y, json::Value{std::numeric_limits<std::uint32_t>::max()});
+    }
+
+    {
+        FeeLevel64 const x{std::numeric_limits<std::uint64_t>::min()};
+        auto y = x.jsonClipped();
+        EXPECT_EQ(y.type(), json::ValueType::UInt);
+        EXPECT_EQ(y, json::Value{0});
+    }
+
+    {
+        FeeLevelDouble const x{std::numeric_limits<double>::max()};
+        auto y = x.jsonClipped();
+        EXPECT_EQ(y.type(), json::ValueType::Real);
+        EXPECT_EQ(y, json::Value{std::numeric_limits<double>::max()});
+    }
+
+    {
+        FeeLevelDouble const x{std::numeric_limits<double>::min()};
+        auto y = x.jsonClipped();
+        EXPECT_EQ(y.type(), json::ValueType::Real);
+        EXPECT_EQ(y, json::Value{std::numeric_limits<double>::min()});
+    }
+
+    {
+        XRPAmount const x{std::numeric_limits<std::int64_t>::max()};
+        auto y = x.jsonClipped();
+        EXPECT_EQ(y.type(), json::ValueType::Int);
+        EXPECT_EQ(y, json::Value{std::numeric_limits<std::int32_t>::max()});
+    }
+
+    {
+        XRPAmount const x{std::numeric_limits<std::int64_t>::min()};
+        auto y = x.jsonClipped();
+        EXPECT_EQ(y.type(), json::ValueType::Int);
+        EXPECT_EQ(y, json::Value{std::numeric_limits<std::int32_t>::min()});
+    }
+}
+
+TEST(UnitsTest, functions)
+{
+    // Explicitly test every defined function for the ValueUnit class
+    // since some of them are templated, but not used anywhere else.
+    using FeeLevel32 = FeeLevel<std::uint32_t>;
+
+    {
+        auto make = [&](auto x) -> FeeLevel64 { return x; };
+        auto explicitmake = [&](auto x) -> FeeLevel64 { return FeeLevel64{x}; };
+
+        [[maybe_unused]]
+        FeeLevel64 const defaulted{};
+        FeeLevel64 test{0};
+        EXPECT_EQ(test.fee(), 0);
+
+        test = explicitmake(beast::kZero);
+        EXPECT_EQ(test.fee(), 0);
+
+        test = beast::kZero;
+        EXPECT_EQ(test.fee(), 0);
+
+        test = explicitmake(100u);
+        EXPECT_EQ(test.fee(), 100);
+
+        FeeLevel64 const targetSame{200u};
+        FeeLevel32 const targetOther{300u};
+        test = make(targetSame);
+        EXPECT_EQ(test.fee(), 200);
+        EXPECT_EQ(test, targetSame);
+        EXPECT_TRUE(test < FeeLevel64{1000});
+        EXPECT_TRUE(test > FeeLevel64{100});
+        test = make(targetOther);
+        EXPECT_EQ(test.fee(), 300);
+        EXPECT_EQ(test, targetOther);
+
+        test = std::uint64_t(200);
+        EXPECT_EQ(test.fee(), 200);
+        test = std::uint32_t(300);
+        EXPECT_EQ(test.fee(), 300);
+
+        test = targetSame;
+        EXPECT_EQ(test.fee(), 200);
+        test = targetOther.fee();
+        EXPECT_EQ(test.fee(), 300);
+        EXPECT_EQ(test, targetOther);
+
+        test = targetSame * 2;
+        EXPECT_EQ(test.fee(), 400);
+        test = 3 * targetSame;
+        EXPECT_EQ(test.fee(), 600);
+        test = targetSame / 10;
+        EXPECT_EQ(test.fee(), 20);
+
+        test += targetSame;
+        EXPECT_EQ(test.fee(), 220);
+
+        test -= targetSame;
+        EXPECT_EQ(test.fee(), 20);
+
+        test++;
+        EXPECT_EQ(test.fee(), 21);
+        ++test;
+        EXPECT_EQ(test.fee(), 22);
+        test--;
+        EXPECT_EQ(test.fee(), 21);
+        --test;
+        EXPECT_EQ(test.fee(), 20);
+
+        test *= 5;
+        EXPECT_EQ(test.fee(), 100);
+        test /= 2;
+        EXPECT_EQ(test.fee(), 50);
+        test %= 13;
+        EXPECT_EQ(test.fee(), 11);
+
+        /*
+        // illegal with unsigned
+        test = -test;
+        EXPECT_EQ(test.fee(), -11);
+        EXPECT_EQ(test.signum(), -1);
+        EXPECT_EQ(to_string(test), "-11");
+        */
+
+        EXPECT_TRUE(test);
+        test = 0;
+        EXPECT_FALSE(test);
+        EXPECT_EQ(test.signum(), 0);
+        test = targetSame;
+        EXPECT_EQ(test.signum(), 1);
+        EXPECT_EQ(to_string(test), "200");
+    }
+    {
+        auto make = [&](auto x) -> FeeLevelDouble { return x; };
+        auto explicitmake = [&](auto x) -> FeeLevelDouble { return FeeLevelDouble{x}; };
+
+        [[maybe_unused]]
+        FeeLevelDouble const defaulted{};
+        FeeLevelDouble test{0};
+        EXPECT_EQ(test.fee(), 0);
+
+        test = explicitmake(beast::kZero);
+        EXPECT_EQ(test.fee(), 0);
+
+        test = beast::kZero;
+        EXPECT_EQ(test.fee(), 0);
+
+        test = explicitmake(100.0);
+        EXPECT_EQ(test.fee(), 100);
+
+        FeeLevelDouble const targetSame{200.0};
+        FeeLevel64 const targetOther{300};
+        test = make(targetSame);
+        EXPECT_EQ(test.fee(), 200);
+        EXPECT_EQ(test, targetSame);
+        EXPECT_TRUE(test < FeeLevelDouble{1000.0});
+        EXPECT_TRUE(test > FeeLevelDouble{100.0});
+        test = targetOther.fee();
+        EXPECT_EQ(test.fee(), 300);
+        EXPECT_EQ(test, targetOther);
+
+        test = 200.0;
+        EXPECT_EQ(test.fee(), 200);
+        test = std::uint64_t(300);
+        EXPECT_EQ(test.fee(), 300);
+
+        test = targetSame;
+        EXPECT_EQ(test.fee(), 200);
+
+        test = targetSame * 2;
+        EXPECT_EQ(test.fee(), 400);
+        test = 3 * targetSame;
+        EXPECT_EQ(test.fee(), 600);
+        test = targetSame / 10;
+        EXPECT_EQ(test.fee(), 20);
+
+        test += targetSame;
+        EXPECT_EQ(test.fee(), 220);
+
+        test -= targetSame;
+        EXPECT_EQ(test.fee(), 20);
+
+        test++;
+        EXPECT_EQ(test.fee(), 21);
+        ++test;
+        EXPECT_EQ(test.fee(), 22);
+        test--;
+        EXPECT_EQ(test.fee(), 21);
+        --test;
+        EXPECT_EQ(test.fee(), 20);
+
+        test *= 5;
+        EXPECT_EQ(test.fee(), 100);
+        test /= 2;
+        EXPECT_EQ(test.fee(), 50);
+        /* illegal with floating
+        test %= 13;
+        EXPECT_EQ(test.fee(), 11);
+        */
+
+        // legal with signed
+        test = -test;
+        EXPECT_EQ(test.fee(), -50);
+        EXPECT_EQ(test.signum(), -1);
+        EXPECT_EQ(to_string(test), "-50.000000");
+
+        EXPECT_TRUE(test);
+        test = 0;
+        EXPECT_FALSE(test);
+        EXPECT_EQ(test.signum(), 0);
+        test = targetSame;
+        EXPECT_EQ(test.signum(), 1);
+        EXPECT_EQ(to_string(test), "200.000000");
+    }
+}
+
+TEST(UnitsTest, initial_xrp)
+{
+    EXPECT_EQ(kInitialXrp.drops(), 100'000'000'000'000'000);
+    EXPECT_EQ(kInitialXrp, XRPAmount{100'000'000'000'000'000});
+}
+
+}  // namespace xrpl::test
diff --git a/src/tests/libxrpl/basics/XRPAmount.cpp b/src/tests/libxrpl/basics/XRPAmount.cpp
new file mode 100644
index 0000000000..243afbd1a0
--- /dev/null
+++ b/src/tests/libxrpl/basics/XRPAmount.cpp
@@ -0,0 +1,295 @@
+#include <xrpl/protocol/XRPAmount.h>
+
+#include <xrpl/beast/utility/Zero.h>
+
+#include <gtest/gtest.h>
+
+#include <cstdint>
+#include <limits>
+
+namespace xrpl {
+
+TEST(XRPAmountTest, sig_num)
+{
+    for (auto i : {-1, 0, 1})
+    {
+        XRPAmount const x(i);
+
+        if (i < 0)
+        {
+            EXPECT_TRUE(x.signum() < 0);
+        }
+        else if (i > 0)
+        {
+            EXPECT_TRUE(x.signum() > 0);
+        }
+        else
+        {
+            EXPECT_EQ(x.signum(), 0);
+        }
+    }
+}
+
+TEST(XRPAmountTest, beast_zero)
+{
+    using beast::kZero;
+
+    for (auto i : {-1, 0, 1})
+    {
+        XRPAmount const x(i);
+
+        EXPECT_TRUE((i == 0) == (x == kZero));
+        EXPECT_TRUE((i != 0) == (x != kZero));
+        EXPECT_TRUE((i < 0) == (x < kZero));
+        EXPECT_TRUE((i > 0) == (x > kZero));
+        EXPECT_TRUE((i <= 0) == (x <= kZero));
+        EXPECT_TRUE((i >= 0) == (x >= kZero));
+
+        EXPECT_TRUE((0 == i) == (kZero == x));
+        EXPECT_TRUE((0 != i) == (kZero != x));
+        EXPECT_TRUE((0 < i) == (kZero < x));
+        EXPECT_TRUE((0 > i) == (kZero > x));
+        EXPECT_TRUE((0 <= i) == (kZero <= x));
+        EXPECT_TRUE((0 >= i) == (kZero >= x));
+    }
+}
+
+TEST(XRPAmountTest, comparisons)
+{
+    for (auto i : {-1, 0, 1})
+    {
+        XRPAmount const x(i);
+
+        for (auto j : {-1, 0, 1})
+        {
+            XRPAmount const y(j);
+
+            EXPECT_EQ((i == j), (x == y));
+            EXPECT_EQ((i != j), (x != y));
+            EXPECT_EQ((i < j), (x < y));
+            EXPECT_EQ((i > j), (x > y));
+            EXPECT_EQ((i <= j), (x <= y));
+            EXPECT_EQ((i >= j), (x >= y));
+        }
+    }
+}
+
+TEST(XRPAmountTest, add_sub)
+{
+    for (auto i : {-1, 0, 1})
+    {
+        XRPAmount const x(i);
+
+        for (auto j : {-1, 0, 1})
+        {
+            XRPAmount const y(j);
+
+            EXPECT_EQ(XRPAmount(i + j), (x + y));
+            EXPECT_EQ(XRPAmount(i - j), (x - y));
+
+            EXPECT_EQ((x + y), (y + x));  // addition is commutative
+        }
+    }
+}
+
+TEST(XRPAmountTest, decimal)
+{
+    // Tautology
+    EXPECT_EQ(kDropsPerXrp.decimalXRP(), 1);
+
+    XRPAmount test{1};
+    EXPECT_EQ(test.decimalXRP(), 0.000001);
+
+    test = -test;
+    EXPECT_EQ(test.decimalXRP(), -0.000001);
+
+    test = 100'000'000;
+    EXPECT_EQ(test.decimalXRP(), 100);
+
+    test = -test;
+    EXPECT_EQ(test.decimalXRP(), -100);
+}
+
+TEST(XRPAmountTest, functions)
+{
+    // Explicitly test every defined function for the XRPAmount class
+    // since some of them are templated, but not used anywhere else.
+    auto make = [&](auto x) -> XRPAmount { return XRPAmount{x}; };
+
+    XRPAmount const defaulted{};
+    (void)defaulted;
+    XRPAmount test{0};
+    EXPECT_EQ(test.drops(), 0);
+
+    test = make(beast::kZero);
+    EXPECT_EQ(test.drops(), 0);
+
+    test = beast::kZero;
+    EXPECT_EQ(test.drops(), 0);
+
+    test = make(100);
+    EXPECT_EQ(test.drops(), 100);
+
+    test = make(100u);
+    EXPECT_EQ(test.drops(), 100);
+
+    XRPAmount const targetSame{200u};
+    test = make(targetSame);
+    EXPECT_EQ(test.drops(), 200);
+    EXPECT_EQ(test, targetSame);
+    EXPECT_TRUE(test < XRPAmount{1000});
+    EXPECT_TRUE(test > XRPAmount{100});
+
+    test = std::int64_t(200);
+    EXPECT_EQ(test.drops(), 200);
+    test = std::uint32_t(300);
+    EXPECT_EQ(test.drops(), 300);
+
+    test = targetSame;
+    EXPECT_EQ(test.drops(), 200);
+    auto testOther = test.dropsAs<std::uint32_t>();
+    EXPECT_TRUE(testOther);
+    EXPECT_EQ(*testOther, 200);  // NOLINT(bugprone-unchecked-optional-access)
+    test = std::numeric_limits<std::uint64_t>::max();
+    testOther = test.dropsAs<std::uint32_t>();
+    EXPECT_FALSE(testOther);
+    test = -1;
+    testOther = test.dropsAs<std::uint32_t>();
+    EXPECT_FALSE(testOther);
+
+    test = targetSame * 2;
+    EXPECT_EQ(test.drops(), 400);
+    test = 3 * targetSame;
+    EXPECT_EQ(test.drops(), 600);
+    test = 20;
+    EXPECT_EQ(test.drops(), 20);
+
+    test += targetSame;
+    EXPECT_EQ(test.drops(), 220);
+
+    test -= targetSame;
+    EXPECT_EQ(test.drops(), 20);
+
+    test *= 5;
+    EXPECT_EQ(test.drops(), 100);
+    test = 50;
+    EXPECT_EQ(test.drops(), 50);
+    test -= 39;
+    EXPECT_EQ(test.drops(), 11);
+
+    // legal with signed
+    test = -test;
+    EXPECT_EQ(test.drops(), -11);
+    EXPECT_EQ(test.signum(), -1);
+    EXPECT_EQ(to_string(test), "-11");
+
+    EXPECT_TRUE(test);
+    test = 0;
+    EXPECT_FALSE(test);
+    EXPECT_EQ(test.signum(), 0);
+    test = targetSame;
+    EXPECT_EQ(test.signum(), 1);
+    EXPECT_EQ(to_string(test), "200");
+}
+
+TEST(XRPAmountTest, mul_ratio)
+{
+    constexpr auto kMaxUInt32 = std::numeric_limits<std::uint32_t>::max();
+    constexpr auto kMaxXrp = std::numeric_limits<XRPAmount::value_type>::max();
+    constexpr auto kMinXrp = std::numeric_limits<XRPAmount::value_type>::min();
+
+    {
+        // multiply by a number that would overflow then divide by the same
+        // number, and check we didn't lose any value
+        XRPAmount big(kMaxXrp);
+        EXPECT_EQ(big, mulRatio(big, kMaxUInt32, kMaxUInt32, true));
+        // rounding mode shouldn't matter as the result is exact
+        EXPECT_EQ(big, mulRatio(big, kMaxUInt32, kMaxUInt32, false));
+
+        // multiply and divide by values that would overflow if done
+        // naively, and check that it gives the correct answer
+        big -= 0xf;  // Subtract a little so it's divisible by 4
+        EXPECT_EQ(mulRatio(big, 3, 4, false).value(), (big.value() / 4) * 3);
+        EXPECT_EQ(mulRatio(big, 3, 4, true).value(), (big.value() / 4) * 3);
+        EXPECT_EQ(big.value() % 4, 0);
+        EXPECT_GT(big.value(), kMaxXrp / 3);
+        EXPECT_LE(big.value() / 4, kMaxXrp / 3);
+    }
+
+    {
+        // Similar test as above, but for negative values
+        XRPAmount big(kMinXrp);  // NOLINT TODO
+        EXPECT_EQ(big, mulRatio(big, kMaxUInt32, kMaxUInt32, true));
+        // rounding mode shouldn't matter as the result is exact
+        EXPECT_EQ(big, mulRatio(big, kMaxUInt32, kMaxUInt32, false));
+
+        // multiply and divide by values that would overflow if done
+        // naively, and check that it gives the correct answer
+        EXPECT_EQ(mulRatio(big, 3, 4, false).value(), (big.value() / 4) * 3);
+        EXPECT_EQ(mulRatio(big, 3, 4, true).value(), (big.value() / 4) * 3);
+        EXPECT_EQ(big.value() % 4, 0);
+        EXPECT_LT(big.value(), kMinXrp / 3);
+        EXPECT_GE(big.value() / 4, kMinXrp / 3);
+    }
+
+    {
+        // small amounts
+        XRPAmount const tiny(1);
+        // Round up should give the smallest allowable number
+        EXPECT_EQ(tiny, mulRatio(tiny, 1, kMaxUInt32, true));
+        // rounding down should be zero
+        EXPECT_EQ(beast::kZero, mulRatio(tiny, 1, kMaxUInt32, false));
+        EXPECT_EQ(beast::kZero, mulRatio(tiny, kMaxUInt32 - 1, kMaxUInt32, false));
+
+        // tiny negative numbers
+        XRPAmount const tinyNeg(-1);
+        // Round up should give zero
+        EXPECT_EQ(beast::kZero, mulRatio(tinyNeg, 1, kMaxUInt32, true));
+        EXPECT_EQ(beast::kZero, mulRatio(tinyNeg, kMaxUInt32 - 1, kMaxUInt32, true));
+        // rounding down should be tiny
+        EXPECT_EQ(tinyNeg, mulRatio(tinyNeg, kMaxUInt32 - 1, kMaxUInt32, false));
+    }
+
+    {  // rounding
+        {
+            XRPAmount const one(1);
+            auto const rup = mulRatio(one, kMaxUInt32 - 1, kMaxUInt32, true);
+            auto const rdown = mulRatio(one, kMaxUInt32 - 1, kMaxUInt32, false);
+            EXPECT_EQ(rup.drops() - rdown.drops(), 1);
+        }
+
+        {
+            XRPAmount const big(kMaxXrp);
+            auto const rup = mulRatio(big, kMaxUInt32 - 1, kMaxUInt32, true);
+            auto const rdown = mulRatio(big, kMaxUInt32 - 1, kMaxUInt32, false);
+            EXPECT_EQ(rup.drops() - rdown.drops(), 1);
+        }
+
+        {
+            XRPAmount const negOne(-1);
+            auto const rup = mulRatio(negOne, kMaxUInt32 - 1, kMaxUInt32, true);
+            auto const rdown = mulRatio(negOne, kMaxUInt32 - 1, kMaxUInt32, false);
+            EXPECT_EQ(rup.drops() - rdown.drops(), 1);
+        }
+    }
+
+    {
+        // division by zero
+        XRPAmount const one(1);
+        EXPECT_ANY_THROW({ mulRatio(one, 1, 0, true); });
+    }
+
+    {
+        // overflow
+        XRPAmount const big(kMaxXrp);
+        EXPECT_ANY_THROW({ mulRatio(big, 2, 1, true); });
+    }
+
+    {
+        // underflow
+        XRPAmount const bigNegative(kMinXrp + 10);
+        EXPECT_EQ(mulRatio(bigNegative, 2, 1, true), kMinXrp);
+    }
+}
+
+}  // namespace xrpl
diff --git a/src/tests/libxrpl/basics/base58.cpp b/src/tests/libxrpl/basics/base58.cpp
new file mode 100644
index 0000000000..d452453f76
--- /dev/null
+++ b/src/tests/libxrpl/basics/base58.cpp
@@ -0,0 +1,438 @@
+#include <xrpl/protocol/detail/token_errors.h>
+
+#include <boost/multiprecision/cpp_int.hpp>  // IWYU pragma: keep
+
+#include <gtest/gtest.h>
+
+#include <algorithm>
+#include <cassert>
+#include <cstdint>
+#include <cstring>
+#include <iomanip>
+#include <iostream>
+#include <limits>
+#include <ranges>
+#include <stdexcept>
+#include <string>
+#include <tuple>
+#include <vector>
+#ifndef _MSC_VER
+
+#include <xrpl/protocol/detail/b58_utils.h>
+#include <xrpl/protocol/tokens.h>
+
+#include <array>
+#include <cstddef>
+#include <random>
+#include <span>
+#include <sstream>
+
+namespace xrpl::test {
+namespace {
+
+[[nodiscard]] inline auto
+randEngine() -> std::mt19937&
+{
+    static std::mt19937 kR = [] {
+        std::random_device rd;
+        return std::mt19937{rd()};
+    }();
+    return kR;
+}
+
+constexpr int kNumTokenTypeIndexes = 9;
+
+[[nodiscard]] inline auto
+tokenTypeAndSize(int i) -> std::tuple<xrpl::TokenType, std::size_t>
+{
+    assert(i < kNumTokenTypeIndexes);
+
+    switch (i)
+    {
+        using enum xrpl::TokenType;
+        case 0:
+            return {None, 20};
+        case 1:
+            return {NodePublic, 32};
+        case 2:
+            return {NodePublic, 33};
+        case 3:
+            return {NodePrivate, 32};
+        case 4:
+            return {AccountID, 20};
+        case 5:
+            return {AccountPublic, 32};
+        case 6:
+            return {AccountPublic, 33};
+        case 7:
+            return {AccountSecret, 32};
+        case 8:
+            return {FamilySeed, 16};
+        default:
+            throw std::invalid_argument(
+                "Invalid token selection passed to tokenTypeAndSize() "
+                "in " __FILE__);
+    }
+}
+
+[[nodiscard]] inline auto
+randomTokenTypeAndSize() -> std::tuple<xrpl::TokenType, std::size_t>
+{
+    using namespace xrpl;
+    auto& rng = randEngine();
+    std::uniform_int_distribution<> d(0, 8);
+    return tokenTypeAndSize(d(rng));
+}
+
+// Return the token type and subspan of `d` to use as test data.
+[[nodiscard]] inline auto
+randomB256TestData(std::span<std::uint8_t> d)
+    -> std::tuple<xrpl::TokenType, std::span<std::uint8_t>>
+{
+    auto& rng = randEngine();
+    std::uniform_int_distribution<std::uint8_t> dist(0, 255);
+    auto [tokType, tokSize] = randomTokenTypeAndSize();
+    std::generate(d.begin(), d.begin() + tokSize, [&] { return dist(rng); });
+    return {tokType, d.subspan(0, tokSize)};
+}
+
+inline void
+printAsChar(std::span<std::uint8_t> a, std::span<std::uint8_t> b)
+{
+    auto asString = [](std::span<std::uint8_t> s) {
+        std::string r;
+        r.resize(s.size());
+        std::ranges::copy(s, r.begin());
+        return r;
+    };
+    auto sa = asString(a);
+    auto sb = asString(b);
+    std::cerr << "\n\n" << sa << "\n" << sb << "\n";
+}
+
+inline void
+printAsInt(std::span<std::uint8_t> a, std::span<std::uint8_t> b)
+{
+    auto asString = [](std::span<std::uint8_t> s) -> std::string {
+        std::stringstream sstr;
+        for (auto i : s)
+        {
+            sstr << std::setw(3) << int(i) << ',';
+        }
+        return sstr.str();
+    };
+    auto sa = asString(a);
+    auto sb = asString(b);
+    std::cerr << "\n\n" << sa << "\n" << sb << "\n";
+}
+
+}  // namespace
+
+namespace multiprecision_utils {
+
+boost::multiprecision::checked_uint512_t
+toBoostMP(std::span<std::uint64_t> in)
+{
+    boost::multiprecision::checked_uint512_t mbp = 0;
+    for (auto const& i : std::views::reverse(in))
+    {
+        mbp <<= 64;
+        mbp += i;
+    }
+    return mbp;
+}
+
+std::vector<std::uint64_t>
+randomBigInt(std::uint8_t minSize = 1, std::uint8_t maxSize = 5)
+{
+    auto eng = randEngine();
+    std::uniform_int_distribution<std::uint8_t> numCoeffDist(minSize, maxSize);
+    std::uniform_int_distribution<std::uint64_t> dist;
+    auto const numCoeff = numCoeffDist(eng);
+    std::vector<std::uint64_t> coeffs;
+    coeffs.reserve(numCoeff);
+    for (int i = 0; i < numCoeff; ++i)
+    {
+        coeffs.push_back(dist(eng));
+    }
+    return coeffs;
+}
+}  // namespace multiprecision_utils
+
+TEST(Base58Test, multiprecision)
+{
+    using namespace boost::multiprecision;
+
+    constexpr std::size_t kIters = 100000;
+    auto eng = randEngine();
+    std::uniform_int_distribution<std::uint64_t> dist;
+    std::uniform_int_distribution<std::uint64_t> dist1(1);
+    for (int i = 0; i < kIters; ++i)
+    {
+        std::uint64_t const d = dist(eng);
+        if (d == 0u)
+            continue;
+        auto bigInt = multiprecision_utils::randomBigInt();
+        auto const boostBigInt =
+            multiprecision_utils::toBoostMP(std::span<std::uint64_t>(bigInt.data(), bigInt.size()));
+
+        auto const refDiv = boostBigInt / d;
+        auto const refMod = boostBigInt % d;
+
+        auto const mod = b58_fast::detail::inplaceBigintDivRem(
+            std::span<uint64_t>(bigInt.data(), bigInt.size()), d);
+        auto const foundDiv = multiprecision_utils::toBoostMP(bigInt);
+        EXPECT_EQ(refMod.convert_to<std::uint64_t>(), mod);
+        EXPECT_EQ(foundDiv, refDiv);
+    }
+    for (int i = 0; i < kIters; ++i)
+    {
+        std::uint64_t const d = dist(eng);
+        auto bigInt = multiprecision_utils::randomBigInt(/*minSize*/ 2);
+        if (bigInt[bigInt.size() - 1] == std::numeric_limits<std::uint64_t>::max())
+        {
+            bigInt[bigInt.size() - 1] -= 1;  // Prevent overflow
+        }
+        auto const boostBigInt =
+            multiprecision_utils::toBoostMP(std::span<std::uint64_t>(bigInt.data(), bigInt.size()));
+
+        auto const refAdd = boostBigInt + d;
+
+        auto const result = b58_fast::detail::inplaceBigintAdd(
+            std::span<uint64_t>(bigInt.data(), bigInt.size()), d);
+        EXPECT_EQ(result, TokenCodecErrc::Success);
+        auto const foundAdd = multiprecision_utils::toBoostMP(bigInt);
+        EXPECT_EQ(refAdd, foundAdd);
+    }
+    for (int i = 0; i < kIters; ++i)
+    {
+        std::uint64_t const d = dist1(eng);
+        // Force overflow
+        std::vector<std::uint64_t> bigInt(5, std::numeric_limits<std::uint64_t>::max());
+
+        auto const boostBigInt =
+            multiprecision_utils::toBoostMP(std::span<std::uint64_t>(bigInt.data(), bigInt.size()));
+
+        auto const refAdd = boostBigInt + d;
+
+        auto const result = b58_fast::detail::inplaceBigintAdd(
+            std::span<uint64_t>(bigInt.data(), bigInt.size()), d);
+        EXPECT_EQ(result, TokenCodecErrc::OverflowAdd);
+        auto const foundAdd = multiprecision_utils::toBoostMP(bigInt);
+        EXPECT_NE(refAdd, foundAdd);
+    }
+    for (int i = 0; i < kIters; ++i)
+    {
+        std::uint64_t const d = dist(eng);
+        auto bigInt = multiprecision_utils::randomBigInt(/* minSize */ 2);
+        // inplace mul requires the most significant coeff to be zero to
+        // hold the result.
+        bigInt[bigInt.size() - 1] = 0;
+        auto const boostBigInt =
+            multiprecision_utils::toBoostMP(std::span<std::uint64_t>(bigInt.data(), bigInt.size()));
+
+        auto const refMul = boostBigInt * d;
+
+        auto const result = b58_fast::detail::inplaceBigintMul(
+            std::span<uint64_t>(bigInt.data(), bigInt.size()), d);
+        EXPECT_EQ(result, TokenCodecErrc::Success);
+        auto const foundMul = multiprecision_utils::toBoostMP(bigInt);
+        EXPECT_EQ(refMul, foundMul);
+    }
+    for (int i = 0; i < kIters; ++i)
+    {
+        std::uint64_t const d = dist1(eng);
+        // Force overflow
+        std::vector<std::uint64_t> bigInt(5, std::numeric_limits<std::uint64_t>::max());
+        auto const boostBigInt =
+            multiprecision_utils::toBoostMP(std::span<std::uint64_t>(bigInt.data(), bigInt.size()));
+
+        auto const refMul = boostBigInt * d;
+
+        auto const result = b58_fast::detail::inplaceBigintMul(
+            std::span<uint64_t>(bigInt.data(), bigInt.size()), d);
+        EXPECT_EQ(result, TokenCodecErrc::InputTooLarge);
+        auto const foundMul = multiprecision_utils::toBoostMP(bigInt);
+        EXPECT_NE(refMul, foundMul);
+    }
+}
+
+TEST(Base58Test, fast_matches_ref)
+{
+    auto testRawEncode = [&](std::span<std::uint8_t> const& b256Data) {
+        std::array<std::uint8_t, 64> b58ResultBuf[2];
+        std::array<std::span<std::uint8_t>, 2> b58Result;
+
+        std::array<std::uint8_t, 64> b256ResultBuf[2];
+        std::array<std::span<std::uint8_t>, 2> b256Result;
+        for (int i = 0; i < 2; ++i)
+        {
+            std::span const outBuf{b58ResultBuf[i]};
+            if (i == 0)
+            {
+                auto const r = xrpl::b58_fast::detail::b256ToB58Be(b256Data, outBuf);
+                EXPECT_TRUE(r);
+                b58Result[i] = r.value();
+            }
+            else
+            {
+                std::array<std::uint8_t, 128> tmpBuf{};
+                std::string const s = xrpl::b58_ref::detail::encodeBase58(
+                    b256Data.data(), b256Data.size(), tmpBuf.data(), tmpBuf.size());
+                EXPECT_TRUE(s.size());
+                b58Result[i] = outBuf.subspan(0, s.size());
+                std::ranges::copy(s, b58Result[i].begin());
+            }
+        }
+        auto const rawB58SameSize = b58Result[0].size() == b58Result[1].size();
+        EXPECT_TRUE(rawB58SameSize);
+        if (rawB58SameSize)
+        {
+            auto const rawB58SameData =
+                memcmp(b58Result[0].data(), b58Result[1].data(), b58Result[0].size()) == 0;
+            EXPECT_TRUE(rawB58SameData);
+            if (!rawB58SameData)
+            {
+                printAsChar(b58Result[0], b58Result[1]);
+            }
+        }
+
+        for (int i = 0; i < 2; ++i)
+        {
+            std::span const outBuf{b256ResultBuf[i].data(), b256ResultBuf[i].size()};
+            if (i == 0)
+            {
+                std::string const in(
+                    b58Result[i].data(), b58Result[i].data() + b58Result[i].size());
+                auto const r = xrpl::b58_fast::detail::b58ToB256Be(in, outBuf);
+                EXPECT_TRUE(r);
+                b256Result[i] = r.value();
+            }
+            else
+            {
+                std::string const st(b58Result[i].begin(), b58Result[i].end());
+                std::string const s = xrpl::b58_ref::detail::decodeBase58(st);
+                EXPECT_TRUE(s.size());
+                b256Result[i] = outBuf.subspan(0, s.size());
+                std::ranges::copy(s, b256Result[i].begin());
+            }
+        }
+
+        auto const rawB256SameSize = b256Result[0].size() == b256Result[1].size();
+        EXPECT_TRUE(rawB256SameSize);
+        if (rawB256SameSize)
+        {
+            auto const rawB256SameData =
+                memcmp(b256Result[0].data(), b256Result[1].data(), b256Result[0].size()) == 0;
+            EXPECT_TRUE(rawB256SameData);
+            if (!rawB256SameData)
+            {
+                printAsInt(b256Result[0], b256Result[1]);
+            }
+        }
+    };
+
+    auto testTokenEncode = [&](xrpl::TokenType const tokType,
+                               std::span<std::uint8_t> const& b256Data) {
+        std::array<std::uint8_t, 64> b58ResultBuf[2];
+        std::array<std::span<std::uint8_t>, 2> b58Result;
+
+        std::array<std::uint8_t, 64> b256ResultBuf[2];
+        std::array<std::span<std::uint8_t>, 2> b256Result;
+        for (int i = 0; i < 2; ++i)
+        {
+            std::span const outBuf{b58ResultBuf[i].data(), b58ResultBuf[i].size()};
+            if (i == 0)
+            {
+                auto const r = xrpl::b58_fast::encodeBase58Token(tokType, b256Data, outBuf);
+                EXPECT_TRUE(r);
+                b58Result[i] = r.value();
+            }
+            else
+            {
+                std::string const s =
+                    xrpl::b58_ref::encodeBase58Token(tokType, b256Data.data(), b256Data.size());
+                EXPECT_TRUE(s.size());
+                b58Result[i] = outBuf.subspan(0, s.size());
+                std::ranges::copy(s, b58Result[i].begin());
+            }
+        }
+        auto const tokenB58SameSize = b58Result[0].size() == b58Result[1].size();
+        EXPECT_TRUE(tokenB58SameSize);
+        if (tokenB58SameSize)
+        {
+            auto const tokenB58SameData =
+                memcmp(b58Result[0].data(), b58Result[1].data(), b58Result[0].size()) == 0;
+            EXPECT_TRUE(tokenB58SameData);
+            if (!tokenB58SameData)
+            {
+                printAsChar(b58Result[0], b58Result[1]);
+            }
+        }
+
+        for (int i = 0; i < 2; ++i)
+        {
+            std::span const outBuf{b256ResultBuf[i].data(), b256ResultBuf[i].size()};
+            if (i == 0)
+            {
+                std::string const in(
+                    b58Result[i].data(), b58Result[i].data() + b58Result[i].size());
+                auto const r = xrpl::b58_fast::decodeBase58Token(tokType, in, outBuf);
+                EXPECT_TRUE(r);
+                b256Result[i] = r.value();
+            }
+            else
+            {
+                std::string const st(b58Result[i].begin(), b58Result[i].end());
+                std::string const s = xrpl::b58_ref::decodeBase58Token(st, tokType);
+                EXPECT_TRUE(s.size());
+                b256Result[i] = outBuf.subspan(0, s.size());
+                std::ranges::copy(s, b256Result[i].begin());
+            }
+        }
+
+        auto const tokenB256SameSize = b256Result[0].size() == b256Result[1].size();
+        EXPECT_TRUE(tokenB256SameSize);
+        if (tokenB256SameSize)
+        {
+            auto const tokenB256SameData =
+                memcmp(b256Result[0].data(), b256Result[1].data(), b256Result[0].size()) == 0;
+            EXPECT_TRUE(tokenB256SameData);
+            if (!tokenB256SameData)
+            {
+                printAsInt(b256Result[0], b256Result[1]);
+            }
+        }
+    };
+
+    auto testIt = [&](xrpl::TokenType const tokType, std::span<std::uint8_t> const& b256Data) {
+        testRawEncode(b256Data);
+        testTokenEncode(tokType, b256Data);
+    };
+
+    // test every token type with data where every byte is the same and the
+    // bytes range from 0-255
+    for (int i = 0; i < kNumTokenTypeIndexes; ++i)
+    {
+        std::array<std::uint8_t, 128> b256DataBuf{};
+        auto const [tokType, tokSize] = tokenTypeAndSize(i);
+        for (int d = 0; d <= 255; ++d)
+        {
+            memset(b256DataBuf.data(), d, tokSize);
+            testIt(tokType, std::span(b256DataBuf.data(), tokSize));
+        }
+    }
+
+    // test with random data
+    constexpr std::size_t kIters = 100000;
+    for (int i = 0; i < kIters; ++i)
+    {
+        std::array<std::uint8_t, 128> b256DataBuf{};
+        auto const [tokType, b256Data] = randomB256TestData(b256DataBuf);
+        testIt(tokType, b256Data);
+    }
+}
+
+}  // namespace xrpl::test
+
+#endif  // _MSC_VER
diff --git a/src/tests/libxrpl/basics/base_uint_test.cpp b/src/tests/libxrpl/basics/base_uint_test.cpp
new file mode 100644
index 0000000000..365b43930c
--- /dev/null
+++ b/src/tests/libxrpl/basics/base_uint_test.cpp
@@ -0,0 +1,360 @@
+#include <xrpl/basics/Blob.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/basics/hardened_hash.h>
+#include <xrpl/beast/utility/Zero.h>
+
+#include <boost/endian/detail/order.hpp>
+
+#include <gtest/gtest.h>
+
+#include <array>
+#include <cassert>
+#include <complex>
+#include <cstddef>
+#include <cstdint>
+#include <iterator>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <type_traits>
+#include <unordered_set>
+#include <utility>
+#include <vector>
+
+namespace xrpl::test {
+
+// a non-hashing Hasher that just copies the bytes.
+// Used to test hash_append in base_uint
+template <std::size_t Bits>
+struct Nonhash
+{
+    static constexpr auto const kEndian = boost::endian::order::big;
+    static constexpr std::size_t kWidth = Bits / 8;
+
+    std::array<std::uint8_t, kWidth> data;
+
+    Nonhash() = default;
+
+    void
+    operator()(void const* key, std::size_t len) noexcept
+    {
+        assert(len == kWidth);
+        memcpy(data.data(), key, len);
+    }
+
+    explicit
+    operator std::size_t() noexcept
+    {
+        return kWidth;
+    }
+};
+
+struct BaseUintTest : public ::testing::Test
+{
+    using BaseUInt96 = BaseUInt<96>;
+    static_assert(std::is_copy_constructible_v<BaseUInt96>);
+    static_assert(std::is_copy_assignable_v<BaseUInt96>);
+
+    static void
+    testComparisons()
+    {
+        {
+            static constexpr std::array<std::pair<std::string_view, std::string_view>, 6> kTestArgs{
+                {{"0000000000000000", "0000000000000001"},
+                 {"0000000000000000", "ffffffffffffffff"},
+                 {"1234567812345678", "2345678923456789"},
+                 {"8000000000000000", "8000000000000001"},
+                 {"aaaaaaaaaaaaaaa9", "aaaaaaaaaaaaaaaa"},
+                 {"fffffffffffffffe", "ffffffffffffffff"}}};
+
+            for (auto const& arg : kTestArgs)
+            {
+                xrpl::BaseUInt<64> const u{arg.first}, v{arg.second};
+                // For code readability, we want to use general boolean
+                // expectations instead of specific EXPECT_LT etc.
+                EXPECT_TRUE(u < v);
+                EXPECT_TRUE(u <= v);
+                EXPECT_TRUE(u != v);
+                EXPECT_FALSE(u == v);
+                EXPECT_FALSE(u > v);
+                EXPECT_FALSE(u >= v);
+                EXPECT_FALSE(v < u);
+                EXPECT_FALSE(v <= u);
+                EXPECT_TRUE(v != u);
+                EXPECT_FALSE(v == u);
+                EXPECT_TRUE(v > u);
+                EXPECT_TRUE(v >= u);
+                EXPECT_TRUE(u == u);
+                EXPECT_TRUE(v == v);
+            }
+        }
+
+        {
+            static constexpr std::array<std::pair<std::string_view, std::string_view>, 6> kTestArgs{
+                {
+                    {"000000000000000000000000", "000000000000000000000001"},
+                    {"000000000000000000000000", "ffffffffffffffffffffffff"},
+                    {"0123456789ab0123456789ab", "123456789abc123456789abc"},
+                    {"555555555555555555555555", "55555555555a555555555555"},
+                    {"aaaaaaaaaaaaaaa9aaaaaaaa", "aaaaaaaaaaaaaaaaaaaaaaaa"},
+                    {"fffffffffffffffffffffffe", "ffffffffffffffffffffffff"},
+                }};
+
+            for (auto const& arg : kTestArgs)
+            {
+                xrpl::BaseUInt<96> const u{arg.first}, v{arg.second};
+                EXPECT_TRUE(u < v);
+                EXPECT_TRUE(u <= v);
+                EXPECT_TRUE(u != v);
+                EXPECT_FALSE(u == v);
+                EXPECT_FALSE(u > v);
+                EXPECT_FALSE(u >= v);
+                EXPECT_FALSE(v < u);
+                EXPECT_FALSE(v <= u);
+                EXPECT_TRUE(v != u);
+                EXPECT_FALSE(v == u);
+                EXPECT_TRUE(v > u);
+                EXPECT_TRUE(v >= u);
+                EXPECT_TRUE(u == u);
+                EXPECT_TRUE(v == v);
+            }
+        }
+    }
+};
+
+TEST_F(BaseUintTest, base_uint)
+{
+    static_assert(!std::is_constructible_v<BaseUInt96, std::complex<double>>);
+    static_assert(!std::is_assignable_v<BaseUInt96&, std::complex<double>>);
+
+    testComparisons();
+
+    // used to verify set insertion (hashing required)
+    std::unordered_set<BaseUInt96, HardenedHash<>> uset;
+
+    Blob const raw{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};
+    EXPECT_EQ(BaseUInt96::kBytes, raw.size());
+
+    BaseUInt96 u = BaseUInt96::fromRaw(raw);
+    uset.insert(u);
+    EXPECT_EQ(raw.size(), u.size());
+    EXPECT_EQ(to_string(u), "0102030405060708090A0B0C");
+    EXPECT_EQ(toShortString(u), "01020304...");
+    EXPECT_EQ(*u.data(), 1);
+    EXPECT_EQ(u.signum(), 1);
+    EXPECT_FALSE(!u);
+    EXPECT_FALSE(u.isZero());
+    EXPECT_TRUE(u.isNonZero());
+    unsigned char t = 0;
+    for (auto& d : u)
+    {
+        EXPECT_EQ(d, ++t);
+    }
+
+    // Test hash_append by "hashing" with a no-op hasher (h)
+    // and then extracting the bytes that were written during hashing
+    // back into another base_uint (w) for comparison with the original
+    Nonhash<96> h{};
+    hash_append(h, u);
+    BaseUInt96 const w =
+        BaseUInt96::fromRaw(std::vector<std::uint8_t>(h.data.begin(), h.data.end()));
+    EXPECT_EQ(w, u);
+
+    BaseUInt96 v{~u};
+    uset.insert(v);
+    EXPECT_EQ(to_string(v), "FEFDFCFBFAF9F8F7F6F5F4F3");
+    EXPECT_EQ(toShortString(v), "FEFDFCFB...");
+    EXPECT_EQ(*v.data(), 0xfe);
+    EXPECT_EQ(v.signum(), 1);
+    EXPECT_FALSE(!v);
+    EXPECT_FALSE(v.isZero());
+    EXPECT_TRUE(v.isNonZero());
+
+    t = 0xff;
+    for (auto& d : v)
+    {
+        EXPECT_EQ(d, --t);
+    }
+
+    EXPECT_LT(u, v);
+    EXPECT_GT(v, u);
+
+    v = u;
+    EXPECT_EQ(v, u);
+
+    BaseUInt96 z{beast::kZero};
+    uset.insert(z);
+    EXPECT_EQ(to_string(z), "000000000000000000000000");
+    EXPECT_EQ(toShortString(z), "00000000...");
+    EXPECT_EQ(*z.data(), 0);
+    EXPECT_EQ(*z.begin(), 0);
+    EXPECT_EQ(*std::prev(z.end(), 1), 0);
+    EXPECT_EQ(z.signum(), 0);
+    EXPECT_TRUE(!z);
+    EXPECT_TRUE(z.isZero());
+    EXPECT_FALSE(z.isNonZero());
+    for (auto& d : z)
+    {
+        EXPECT_EQ(d, 0);
+    }
+
+    BaseUInt96 n{z};
+    n++;
+    EXPECT_EQ(n, BaseUInt96(1));
+    n--;
+    EXPECT_EQ(n, beast::kZero);
+    EXPECT_EQ(n, z);
+    n--;
+    EXPECT_EQ(to_string(n), "FFFFFFFFFFFFFFFFFFFFFFFF");
+    EXPECT_EQ(toShortString(n), "FFFFFFFF...");
+    n = beast::kZero;
+    EXPECT_EQ(n, z);
+
+    BaseUInt96 zp1{z};
+    zp1++;
+    BaseUInt96 zm1{z};
+    zm1--;
+    BaseUInt96 const x{zm1 ^ zp1};
+    uset.insert(x);
+    EXPECT_EQ(to_string(x), "FFFFFFFFFFFFFFFFFFFFFFFE") << to_string(x);
+    EXPECT_EQ(toShortString(x), "FFFFFFFF...") << toShortString(x);
+
+    EXPECT_EQ(uset.size(), 4);
+
+    BaseUInt96 tmp;
+    EXPECT_TRUE(tmp.parseHex(to_string(u)));
+    EXPECT_EQ(tmp, u);
+    tmp = z;
+
+    // fails with extra char
+    EXPECT_FALSE(tmp.parseHex("A" + to_string(u)));
+    tmp = z;
+
+    // fails with extra char at end
+    EXPECT_FALSE(tmp.parseHex(to_string(u) + "A"));
+
+    // fails with a non-hex character at some point in the string:
+    tmp = z;
+
+    for (std::size_t i = 0; i != 24; ++i)
+    {
+        std::string x = to_string(z);
+        x[i] = ('G' + (i % 10));
+        EXPECT_FALSE(tmp.parseHex(x));
+    }
+
+    // Walking 1s:
+    for (std::size_t i = 0; i != 24; ++i)
+    {
+        std::string s1 = "000000000000000000000000";
+        s1[i] = '1';
+
+        EXPECT_TRUE(tmp.parseHex(s1));
+        EXPECT_EQ(to_string(tmp), s1);
+    }
+
+    // Walking 0s:
+    for (std::size_t i = 0; i != 24; ++i)
+    {
+        std::string s1 = "111111111111111111111111";
+        s1[i] = '0';
+
+        EXPECT_TRUE(tmp.parseHex(s1));
+        EXPECT_EQ(to_string(tmp), s1);
+    }
+
+    // Constexpr constructors
+    {
+        static_assert(BaseUInt96{}.signum() == 0);
+        static_assert(BaseUInt96("0").signum() == 0);
+        static_assert(BaseUInt96("000000000000000000000000").signum() == 0);
+        static_assert(BaseUInt96("000000000000000000000001").signum() == 1);
+        static_assert(BaseUInt96("800000000000000000000000").signum() == 1);
+
+// Everything within the #if should fail during compilation.
+#if 0
+            // Too few characters
+            static_assert(BaseUInt96("00000000000000000000000").signum() == 0);
+
+            // Too many characters
+            static_assert(BaseUInt96("0000000000000000000000000").signum() == 0);
+
+            // Non-hex characters
+            static_assert(BaseUInt96("00000000000000000000000 ").signum() == 1);
+            static_assert(BaseUInt96("00000000000000000000000/").signum() == 1);
+            static_assert(BaseUInt96("00000000000000000000000:").signum() == 1);
+            static_assert(BaseUInt96("00000000000000000000000@").signum() == 1);
+            static_assert(BaseUInt96("00000000000000000000000G").signum() == 1);
+            static_assert(BaseUInt96("00000000000000000000000`").signum() == 1);
+            static_assert(BaseUInt96("00000000000000000000000g").signum() == 1);
+            static_assert(BaseUInt96("00000000000000000000000~").signum() == 1);
+#endif  // 0
+
+        // Using the constexpr constructor in a non-constexpr context
+        // with an error in the parsing throws an exception.
+        {
+            // Invalid length for string.
+            bool caught = false;
+            try
+            {
+                // Try to prevent constant evaluation.
+                std::vector<char> str(23, '7');
+                std::string_view const sView(str.data(), str.size());
+                [[maybe_unused]] BaseUInt96 const t96(sView);
+            }
+            catch (std::invalid_argument const& e)
+            {
+                EXPECT_EQ(e.what(), std::string("invalid length for hex string"));
+                caught = true;
+            }
+            EXPECT_TRUE(caught);
+        }
+        {
+            // Invalid character in string.
+            bool caught = false;
+            try
+            {
+                // Try to prevent constant evaluation.
+                std::vector<char> str(23, '7');
+                str.push_back('G');
+                std::string_view const sView(str.data(), str.size());
+                [[maybe_unused]] BaseUInt96 const t96(sView);
+            }
+            catch (std::range_error const& e)
+            {
+                EXPECT_EQ(e.what(), std::string("invalid hex character"));
+                caught = true;
+            }
+            EXPECT_TRUE(caught);
+        }
+
+        // Verify that constexpr base_uints interpret a string the same
+        // way parseHex() does.
+        struct StrBaseUInt
+        {
+            char const* const str;
+            BaseUInt96 tst;
+
+            constexpr StrBaseUInt(char const* s) : str(s), tst(s)
+            {
+            }
+        };
+        constexpr StrBaseUInt kTestCases[] = {
+            "000000000000000000000000",
+            "000000000000000000000001",
+            "fedcba9876543210ABCDEF91",
+            "19FEDCBA0123456789abcdef",
+            "800000000000000000000000",
+            "fFfFfFfFfFfFfFfFfFfFfFfF",
+        };
+
+        for (StrBaseUInt const& t : kTestCases)
+        {
+            BaseUInt96 t96;
+            EXPECT_TRUE(t96.parseHex(t.str));
+            EXPECT_EQ(t96, t.tst);
+        }
+    }
+}
+
+}  // namespace xrpl::test
diff --git a/src/test/basics/hardened_hash_test.cpp b/src/tests/libxrpl/basics/hardened_hash.cpp
similarity index 84%
rename from src/test/basics/hardened_hash_test.cpp
rename to src/tests/libxrpl/basics/hardened_hash.cpp
index 8b10967932..4f51ce4305 100644
--- a/src/test/basics/hardened_hash_test.cpp
+++ b/src/tests/libxrpl/basics/hardened_hash.cpp
@@ -1,6 +1,8 @@
 #include <xrpl/basics/hardened_hash.h>
+
 #include <xrpl/beast/hash/hash_append.h>
-#include <xrpl/beast/unit_test/suite.h>
+
+#include <gtest/gtest.h>
 
 #include <array>
 #include <cstddef>
@@ -153,20 +155,20 @@ static_assert(sha256_t::kBits == 256, "sha256_t must have 256 bits");
 
 namespace xrpl {
 
-class hardened_hash_test : public beast::unit_test::Suite
+class HardenedHashTest : public ::testing::Test
 {
 public:
     template <class T>
-    void
+    static void
     check()
     {
         T t{};
         HardenedHash<>()(t);
-        pass();
+        SUCCEED();
     }
 
     template <template <class T> class U>
-    void
+    static void
     checkUserType()
     {
         check<U<bool>>();
@@ -191,48 +193,35 @@ public:
     }
 
     template <template <class T> class C>
-    void
+    static void
     checkContainer()
     {
         {
             C<detail::TestUserTypeMember<std::string>> const c;
         }
 
-        pass();
+        SUCCEED();
 
         {
             C<detail::TestUserTypeFree<std::string>> const c;
         }
 
-        pass();
-    }
-
-    void
-    testUserTypes()
-    {
-        testcase("user types");
-        checkUserType<detail::TestUserTypeMember>();
-        checkUserType<detail::TestUserTypeFree>();
-    }
-
-    void
-    testContainers()
-    {
-        testcase("containers");
-        checkContainer<detail::test_hardened_unordered_set>();
-        checkContainer<detail::test_hardened_unordered_map>();
-        checkContainer<detail::test_hardened_unordered_multiset>();
-        checkContainer<detail::test_hardened_unordered_multimap>();
-    }
-
-    void
-    run() override
-    {
-        testUserTypes();
-        testContainers();
+        SUCCEED();
     }
 };
 
-BEAST_DEFINE_TESTSUITE(hardened_hash, basics, xrpl);
+TEST_F(HardenedHashTest, user_types)
+{
+    checkUserType<detail::TestUserTypeMember>();
+    checkUserType<detail::TestUserTypeFree>();
+}
+
+TEST_F(HardenedHashTest, containers)
+{
+    checkContainer<detail::test_hardened_unordered_set>();
+    checkContainer<detail::test_hardened_unordered_map>();
+    checkContainer<detail::test_hardened_unordered_multiset>();
+    checkContainer<detail::test_hardened_unordered_multimap>();
+}
 
 }  // namespace xrpl
diff --git a/src/tests/libxrpl/basics/join.cpp b/src/tests/libxrpl/basics/join.cpp
new file mode 100644
index 0000000000..66c832678b
--- /dev/null
+++ b/src/tests/libxrpl/basics/join.cpp
@@ -0,0 +1,80 @@
+#include <xrpl/basics/join.h>
+
+#include <xrpl/basics/base_uint.h>
+
+#include <gtest/gtest.h>
+
+#include <array>
+#include <cstddef>
+#include <initializer_list>
+#include <sstream>
+#include <string>
+#include <vector>
+
+namespace xrpl::test {
+
+struct JoinTest : public ::testing::Test
+{
+};
+
+TEST_F(JoinTest, join)
+{
+    auto test = [](auto collectionanddelimiter, std::string expected) {
+        std::stringstream ss;
+        // Put something else in the buffer before and after to ensure that
+        // the << operator returns the stream correctly.
+        ss << "(" << collectionanddelimiter << ")";
+        auto const str = ss.str();
+        EXPECT_EQ(str.substr(1, str.length() - 2), expected);
+        EXPECT_EQ(str.front(), '(');
+        EXPECT_EQ(str.back(), ')');
+    };
+
+    // C++ array
+    test(CollectionAndDelimiter(std::array<int, 4>{2, -1, 5, 10}, "/"), "2/-1/5/10");
+    // One item C++ array edge case
+    test(CollectionAndDelimiter(std::array<std::string, 1>{"test"}, " & "), "test");
+    // Empty C++ array edge case
+    test(CollectionAndDelimiter(std::array<int, 0>{}, ","), "");
+    {
+        // C-style array
+        char letters[4]{'w', 'a', 's', 'd'};
+        test(CollectionAndDelimiter(letters, std::to_string(0)), "w0a0s0d");
+    }
+    {
+        // Auto sized C-style array
+        std::string words[]{"one", "two", "three", "four"};
+        test(CollectionAndDelimiter(words, "\n"), "one\ntwo\nthree\nfour");
+    }
+    {
+        // One item C-style array edge case
+        std::string words[]{"thing"};
+        test(CollectionAndDelimiter(words, "\n"), "thing");
+    }
+    // Initializer list
+    test(CollectionAndDelimiter(std::initializer_list<size_t>{19, 25}, "+"), "19+25");
+    // vector
+    test(CollectionAndDelimiter(std::vector<int>{0, 42}, std::to_string(99)), "09942");
+    // vector with one item edge case
+    test(CollectionAndDelimiter(std::vector<std::string>{"master"}, "xxx"), "master");
+    // vector with one non-trivial streamable item edge case
+    test(
+        CollectionAndDelimiter(std::vector<uint256>{uint256{1}}, "xxx"),
+        "0000000000000000000000000000000000000000000000000000000000000001");
+    // empty vector edge case
+    test(CollectionAndDelimiter(std::vector<uint256>{}, ","), "");
+    // C-style string
+    test(CollectionAndDelimiter("string", " "), "s t r i n g");
+    // Empty C-style string edge case
+    test(CollectionAndDelimiter("", "*"), "");
+    // Single char C-style string edge case
+    test(CollectionAndDelimiter("x", "*"), "x");
+    // std::string
+    test(CollectionAndDelimiter(std::string{"string"}, "-"), "s-t-r-i-n-g");
+    // Empty std::string edge case
+    test(CollectionAndDelimiter(std::string{""}, "*"), "");
+    // Single char std::string edge case
+    test(CollectionAndDelimiter(std::string{"y"}, "*"), "y");
+}
+
+}  // namespace xrpl::test
diff --git a/src/tests/libxrpl/json/Value.cpp b/src/tests/libxrpl/json/Value.cpp
index 03f565dffb..a1cd8160d7 100644
--- a/src/tests/libxrpl/json/Value.cpp
+++ b/src/tests/libxrpl/json/Value.cpp
@@ -838,7 +838,7 @@ TEST(json_value, compact)
 {
     json::Value j;
     json::Reader r;
-    char const* s("{\"array\":[{\"12\":23},{},null,false,0.5]}");
+    char const* s(R"({"array":[{"12":23},{},null,false,0.5]})");
 
     auto countLines = [](std::string const& str) {
         return 1 + std::count_if(str.begin(), str.end(), [](char c) { return c == '\n'; });
diff --git a/src/tests/libxrpl/resource/Logic.cpp b/src/tests/libxrpl/resource/Logic.cpp
new file mode 100644
index 0000000000..1f935ebf4b
--- /dev/null
+++ b/src/tests/libxrpl/resource/Logic.cpp
@@ -0,0 +1,241 @@
+#include <xrpl/resource/detail/Logic.h>
+
+#include <xrpl/basics/Log.h>
+#include <xrpl/basics/chrono.h>
+#include <xrpl/basics/random.h>
+#include <xrpl/beast/insight/NullCollector.h>
+#include <xrpl/beast/net/IPAddressV4.h>
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/resource/Charge.h>
+#include <xrpl/resource/Consumer.h>
+#include <xrpl/resource/Disposition.h>
+#include <xrpl/resource/Gossip.h>
+#include <xrpl/resource/detail/Tuning.h>
+
+#include <boost/utility/base_from_member.hpp>
+
+#include <gtest/gtest.h>
+#include <helpers/TestSink.h>
+
+#include <chrono>
+#include <cstdint>
+#include <string>
+
+namespace xrpl::Resource {
+
+class ResourceManagerTest : public ::testing::Test
+{
+protected:
+    beast::Journal const j_{TestSink::instance()};
+
+    class TestLogic : private boost::base_from_member<TestStopwatch>, public Logic
+    {
+    private:
+        using clock_type = boost::base_from_member<TestStopwatch>;
+
+    public:
+        explicit TestLogic(beast::Journal journal)
+            : Logic(beast::insight::NullCollector::make(), member, journal)
+        {
+        }
+
+        void
+        advance()
+        {
+            ++member;
+        }
+
+        TestStopwatch&
+        clock()
+        {
+            return member;
+        }
+    };
+
+    //--------------------------------------------------------------------------
+
+    static void
+    populateGossip(Gossip& gossip)
+    {
+        std::uint8_t const v(10 + randInt(9));
+        std::uint8_t const n(10 + randInt(9));
+        gossip.items.reserve(n);
+        for (std::uint8_t i = 0; i < n; ++i)
+        {
+            Gossip::Item item;
+            item.balance = 100 + randInt(499);
+            beast::IP::AddressV4::bytes_type const d = {{
+                192,
+                0,
+                2,
+                static_cast<std::uint8_t>(v + i),
+            }};
+            item.address = beast::IP::Endpoint{beast::IP::AddressV4{d}};
+            gossip.items.push_back(item);
+        }
+    }
+};
+
+TEST_F(ResourceManagerTest, limited_warn_drop)
+{
+    TestLogic logic{j_};
+
+    Charge const fee{kDropThreshold + 1};
+    beast::IP::Endpoint const addr{beast::IP::Endpoint::fromString("192.0.2.2")};
+
+    {
+        Consumer c{logic.newInboundEndpoint(addr)};
+
+        // Create load until we get a warning
+        int n = 10000;
+        bool warned = false;
+
+        while (--n >= 0)
+        {
+            if (c.charge(fee) == Disposition::Warn)
+            {
+                warned = true;
+                break;
+            }
+            ++logic.clock();
+        }
+
+        ASSERT_TRUE(warned) << "Loop count exceeded without warning";
+
+        // Create load until we get dropped
+        bool dropped = false;
+        while (--n >= 0)
+        {
+            if (c.charge(fee) == Disposition::Drop)
+            {
+                dropped = true;
+                // Disconnect abusive Consumer
+                EXPECT_TRUE(c.disconnect(j_));
+                break;
+            }
+            ++logic.clock();
+        }
+
+        ASSERT_TRUE(dropped) << "Loop count exceeded without dropping";
+    }
+
+    // Make sure the consumer is on the blacklist for a while.
+    {
+        Consumer const c{logic.newInboundEndpoint(addr)};
+        logic.periodicActivity();
+        EXPECT_EQ(c.disposition(), Disposition::Drop) << "Dropped consumer not put on blacklist";
+    }
+
+    // Makes sure the Consumer is eventually removed from blacklist
+    bool readmitted = false;
+    {
+        using namespace std::chrono_literals;
+        // Give Consumer time to become readmitted.  Should never
+        // exceed expiration time.
+        auto n = kSecondsUntilExpiration + 1s;
+        while (--n > 0s)
+        {
+            ++logic.clock();
+            logic.periodicActivity();
+            Consumer const c{logic.newInboundEndpoint(addr)};
+            if (c.disposition() != Disposition::Drop)
+            {
+                readmitted = true;
+                break;
+            }
+        }
+    }
+    EXPECT_TRUE(readmitted) << "Dropped Consumer left on blacklist too long";
+}
+
+TEST_F(ResourceManagerTest, unlimited_warn_drop)
+{
+    TestLogic logic{j_};
+
+    Charge const fee{kDropThreshold + 1};
+    beast::IP::Endpoint const addr{beast::IP::Endpoint::fromString("192.0.2.2")};
+    Consumer c{logic.newUnlimitedEndpoint(addr)};
+
+    // Create load until we get a warning
+    int n = 10000;
+    bool warned = false;
+
+    while (--n >= 0)
+    {
+        if (c.charge(fee) == Disposition::Warn)
+        {
+            warned = true;
+            break;
+        }
+        ++logic.clock();
+    }
+
+    EXPECT_FALSE(warned) << "Should loop forever with no warning";
+}
+
+TEST_F(ResourceManagerTest, charges)
+{
+    TestLogic logic{j_};
+
+    {
+        beast::IP::Endpoint const address{beast::IP::Endpoint::fromString("192.0.2.1")};
+        Consumer c{logic.newInboundEndpoint(address)};
+        Charge const fee{1000};
+        JLOG(j_.info()) << "Charging " << c.toString() << " " << fee << " per second";
+        c.charge(fee);
+        for (int i = 0; i < 128; ++i)
+        {
+            JLOG(j_.info()) << "Time= " << logic.clock().now().time_since_epoch().count()
+                            << ", Balance = " << c.balance();
+            logic.advance();
+        }
+    }
+
+    {
+        beast::IP::Endpoint const address{beast::IP::Endpoint::fromString("192.0.2.2")};
+        Consumer c{logic.newInboundEndpoint(address)};
+        Charge const fee{1000};
+        JLOG(j_.info()) << "Charging " << c.toString() << " " << fee << " per second";
+        for (int i = 0; i < 128; ++i)
+        {
+            c.charge(fee);
+            JLOG(j_.info()) << "Time= " << logic.clock().now().time_since_epoch().count()
+                            << ", Balance = " << c.balance();
+            logic.advance();
+        }
+    }
+}
+
+TEST_F(ResourceManagerTest, imports)
+{
+    TestLogic logic{j_};
+
+    Gossip g[5];
+
+    for (auto& i : g)
+        populateGossip(i);
+
+    for (int i = 0; i < 5; ++i)
+        logic.importConsumers(std::to_string(i), g[i]);
+}
+
+TEST_F(ResourceManagerTest, import)
+{
+    TestLogic logic{j_};
+
+    Gossip g;
+    Gossip::Item item;
+    item.balance = 100;
+    beast::IP::AddressV4::bytes_type const d = {{
+        192,
+        0,
+        2,
+        1,
+    }};
+    item.address = beast::IP::Endpoint{beast::IP::AddressV4{d}};
+    g.items.push_back(item);
+
+    logic.importConsumers("g", g);
+}
+
+}  // namespace xrpl::Resource
diff --git a/src/tests/libxrpl/shamap/FetchPack.cpp b/src/tests/libxrpl/shamap/FetchPack.cpp
new file mode 100644
index 0000000000..05854d482f
--- /dev/null
+++ b/src/tests/libxrpl/shamap/FetchPack.cpp
@@ -0,0 +1,22 @@
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/shamap/SHAMap.h>
+#include <xrpl/shamap/SHAMapMissingNode.h>
+
+#include <gtest/gtest.h>
+#include <helpers/TestSink.h>
+#include <shamap/common.h>
+
+#include <memory>
+
+namespace xrpl::tests {
+
+TEST(FetchPackTest, construct_table)
+{
+    beast::Journal const j{TestSink::instance()};
+    TestNodeFamily f{j};
+    std::shared_ptr<SHAMap> const t1{std::make_shared<SHAMap>(SHAMapType::FREE, f)};
+
+    EXPECT_NE(t1, nullptr);
+}
+
+}  // namespace xrpl::tests
diff --git a/src/tests/libxrpl/shamap/SHAMap.cpp b/src/tests/libxrpl/shamap/SHAMap.cpp
new file mode 100644
index 0000000000..238c34bf9c
--- /dev/null
+++ b/src/tests/libxrpl/shamap/SHAMap.cpp
@@ -0,0 +1,349 @@
+#include <xrpl/shamap/SHAMap.h>
+
+#include <xrpl/basics/Blob.h>
+#include <xrpl/basics/Buffer.h>
+#include <xrpl/basics/SHAMapHash.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/beast/utility/Zero.h>
+#include <xrpl/shamap/SHAMapInnerNode.h>
+#include <xrpl/shamap/SHAMapItem.h>
+#include <xrpl/shamap/SHAMapLeafNode.h>
+#include <xrpl/shamap/SHAMapMissingNode.h>
+#include <xrpl/shamap/SHAMapTreeNode.h>
+
+#include <gtest/gtest.h>
+#include <helpers/TestSink.h>
+#include <shamap/common.h>
+
+#include <algorithm>
+#include <array>
+#include <cstddef>
+#include <cstdint>
+#include <memory>
+#include <string>
+#include <string_view>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+namespace xrpl::tests {
+
+#ifndef __INTELLISENSE__
+static_assert(std::is_nothrow_destructible<SHAMap>{});
+static_assert(!std::is_default_constructible<SHAMap>{});
+static_assert(!std::is_copy_constructible<SHAMap>{});
+static_assert(!std::is_copy_assignable<SHAMap>{});
+static_assert(!std::is_move_constructible<SHAMap>{});
+static_assert(!std::is_move_assignable<SHAMap>{});
+
+static_assert(std::is_nothrow_destructible<SHAMap::ConstIterator>{});
+static_assert(std::is_copy_constructible<SHAMap::ConstIterator>{});
+static_assert(std::is_copy_assignable<SHAMap::ConstIterator>{});
+static_assert(std::is_move_constructible<SHAMap::ConstIterator>{});
+static_assert(std::is_move_assignable<SHAMap::ConstIterator>{});
+
+static_assert(std::is_nothrow_destructible<SHAMapItem>{});
+static_assert(!std::is_default_constructible<SHAMapItem>{});
+static_assert(!std::is_copy_constructible<SHAMapItem>{});
+
+static_assert(std::is_nothrow_destructible<SHAMapNodeID>{});
+static_assert(std::is_default_constructible<SHAMapNodeID>{});
+static_assert(std::is_copy_constructible<SHAMapNodeID>{});
+static_assert(std::is_copy_assignable<SHAMapNodeID>{});
+static_assert(std::is_move_constructible<SHAMapNodeID>{});
+static_assert(std::is_move_assignable<SHAMapNodeID>{});
+
+static_assert(std::is_nothrow_destructible<SHAMapHash>{});
+static_assert(std::is_default_constructible<SHAMapHash>{});
+static_assert(std::is_copy_constructible<SHAMapHash>{});
+static_assert(std::is_copy_assignable<SHAMapHash>{});
+static_assert(std::is_move_constructible<SHAMapHash>{});
+static_assert(std::is_move_assignable<SHAMapHash>{});
+
+static_assert(std::is_nothrow_destructible<SHAMapTreeNode>{});
+static_assert(!std::is_default_constructible<SHAMapTreeNode>{});
+static_assert(!std::is_copy_constructible<SHAMapTreeNode>{});
+static_assert(!std::is_copy_assignable<SHAMapTreeNode>{});
+static_assert(!std::is_move_constructible<SHAMapTreeNode>{});
+static_assert(!std::is_move_assignable<SHAMapTreeNode>{});
+
+static_assert(std::is_nothrow_destructible<SHAMapInnerNode>{});
+static_assert(!std::is_default_constructible<SHAMapInnerNode>{});
+static_assert(!std::is_copy_constructible<SHAMapInnerNode>{});
+static_assert(!std::is_copy_assignable<SHAMapInnerNode>{});
+static_assert(!std::is_move_constructible<SHAMapInnerNode>{});
+static_assert(!std::is_move_assignable<SHAMapInnerNode>{});
+
+static_assert(std::is_nothrow_destructible<SHAMapLeafNode>{});
+static_assert(!std::is_default_constructible<SHAMapLeafNode>{});
+static_assert(!std::is_copy_constructible<SHAMapLeafNode>{});
+static_assert(!std::is_copy_assignable<SHAMapLeafNode>{});
+static_assert(!std::is_move_constructible<SHAMapLeafNode>{});
+static_assert(!std::is_move_assignable<SHAMapLeafNode>{});
+#endif
+
+inline bool
+operator!=(SHAMapItem const& a, SHAMapItem const& b)
+{
+    return a.key() != b.key();
+}
+
+struct SHAMapBackingMode
+{
+    bool backed;
+    std::string_view testName;
+};
+
+constexpr SHAMapBackingMode kBackedMode{.backed = true, .testName = "backed"};
+constexpr SHAMapBackingMode kUnbackedMode{.backed = false, .testName = "unbacked"};
+
+std::string
+shamapBackingModeName(::testing::TestParamInfo<SHAMapBackingMode> const& info)
+{
+    return std::string{info.param.testName};
+}
+
+class SHAMapTest : public ::testing::TestWithParam<SHAMapBackingMode>
+{
+protected:
+    beast::Journal const j_{TestSink::instance()};
+
+    static Buffer
+    intToVuc(std::uint8_t v)
+    {
+        Buffer vuc{32};
+        std::fill_n(vuc.data(), vuc.size(), v);
+        return vuc;
+    }
+};
+
+TEST_P(SHAMapTest, add_traverse_snapshot_build_tear_and_iterate)
+{
+    auto const testMode = GetParam();
+    tests::TestNodeFamily f{j_};
+
+    // kH3 and kH4 differ only in the leaf, same terminal node (level 19)
+    constexpr uint256 kH1("092891fe4ef6cee585fdc6fda0e09eb4d386363158ec3321b8123e5a772c6ca7");
+    constexpr uint256 kH2("436ccbac3347baa1f1e53baeef1f43334da88f1f6d70d963b833afd6dfa289fe");
+    constexpr uint256 kH3("b92891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8");
+    constexpr uint256 kH4("b92891fe4ef6cee585fdc6fda2e09eb4d386363158ec3321b8123e5a772c6ca8");
+
+    SHAMap sMap{SHAMapType::FREE, f};
+    sMap.invariants();
+    if (!testMode.backed)
+        sMap.setUnbacked();
+
+    auto i1 = makeShamapitem(kH1, intToVuc(1));
+    auto i2 = makeShamapitem(kH2, intToVuc(2));
+    auto i3 = makeShamapitem(kH3, intToVuc(3));
+    auto i4 = makeShamapitem(kH4, intToVuc(4));
+
+    EXPECT_TRUE(sMap.addItem(SHAMapNodeType::TnTransactionNm, makeShamapitem(*i2))) << "no add";
+    sMap.invariants();
+    EXPECT_TRUE(sMap.addItem(SHAMapNodeType::TnTransactionNm, makeShamapitem(*i1))) << "no add";
+    sMap.invariants();
+
+    auto i = sMap.begin();
+    auto e = sMap.end();
+    EXPECT_FALSE(i == e || (*i != *i1)) << "bad traverse";
+    ++i;
+    EXPECT_FALSE(i == e || (*i != *i2)) << "bad traverse";
+    ++i;
+    EXPECT_EQ(i, e) << "bad traverse";
+    sMap.addItem(SHAMapNodeType::TnTransactionNm, makeShamapitem(*i4));
+    sMap.invariants();
+    sMap.delItem(i2->key());
+    sMap.invariants();
+    sMap.addItem(SHAMapNodeType::TnTransactionNm, makeShamapitem(*i3));
+    sMap.invariants();
+    i = sMap.begin();
+    e = sMap.end();
+    EXPECT_FALSE(i == e || (*i != *i1)) << "bad traverse";
+    ++i;
+    EXPECT_FALSE(i == e || (*i != *i3)) << "bad traverse";
+    ++i;
+    EXPECT_FALSE(i == e || (*i != *i4)) << "bad traverse";
+    ++i;
+    EXPECT_EQ(i, e) << "bad traverse";
+
+    SHAMapHash const mapHash = sMap.getHash();
+    std::shared_ptr<SHAMap> const map2 = sMap.snapShot(false);
+    map2->invariants();
+    EXPECT_EQ(sMap.getHash(), mapHash) << "bad snapshot";
+    EXPECT_EQ(map2->getHash(), mapHash) << "bad snapshot";
+
+    SHAMap::Delta delta;
+    ASSERT_TRUE(sMap.compare(*map2, delta, 100));
+    EXPECT_TRUE(delta.empty());
+
+    EXPECT_TRUE(sMap.delItem(sMap.begin()->key())) << "bad mod";
+    sMap.invariants();
+    EXPECT_NE(sMap.getHash(), mapHash) << "bad snapshot";
+    EXPECT_EQ(map2->getHash(), mapHash) << "bad snapshot";
+
+    ASSERT_TRUE(sMap.compare(*map2, delta, 100));
+    ASSERT_EQ(delta.size(), 1);
+    EXPECT_EQ(delta.begin()->first, kH1);
+    EXPECT_EQ(delta.begin()->second.first, nullptr);
+    ASSERT_NE(delta.begin()->second.second, nullptr);
+    EXPECT_EQ(delta.begin()->second.second->key(), kH1);
+
+    sMap.dump();
+    {
+        constexpr std::array kKeys{
+            uint256{"b92891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8"},
+            uint256{"b92881fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8"},
+            uint256{"b92691fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8"},
+            uint256{"b92791fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8"},
+            uint256{"b91891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8"},
+            uint256{"b99891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8"},
+            uint256{"f22891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8"},
+            uint256{"292891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8"},
+        };
+
+        constexpr std::array kHashes{
+            uint256{"B7387CFEA0465759ADC718E8C42B52D2309D179B326E239EB5075C64B6281F7F"},
+            uint256{"FBC195A9592A54AB44010274163CB6BA95F497EC5BA0A8831845467FB2ECE266"},
+            uint256{"4E7D2684B65DFD48937FFB775E20175C43AF0C94066F7D5679F51AE756795B75"},
+            uint256{"7A2F312EB203695FFD164E038E281839EEF06A1B99BFC263F3CECC6C74F93E07"},
+            uint256{"395A6691A372387A703FB0F2C6D2C405DAF307D0817F8F0E207596462B0E3A3E"},
+            uint256{"D044C0A696DE3169CC70AE216A1564D69DE96582865796142CE7D98A84D9DDE4"},
+            uint256{"76DCC77C4027309B5A91AD164083264D70B77B5E43E08AEDA5EBF94361143615"},
+            uint256{"DF4220E93ADC6F5569063A01B4DC79F8DB9553B6A3222ADE23DEA02BBE7230E5"},
+        };
+
+        SHAMap map{SHAMapType::FREE, f};
+        if (!testMode.backed)
+            map.setUnbacked();
+
+        EXPECT_EQ(map.getHash(), beast::kZero);
+        for (std::size_t k = 0; k < kKeys.size(); ++k)
+        {
+            EXPECT_TRUE(map.addItem(
+                SHAMapNodeType::TnTransactionNm,
+                makeShamapitem(kKeys[k], intToVuc(static_cast<std::uint8_t>(k)))));
+            EXPECT_EQ(map.getHash().asUInt256(), kHashes[k]);
+            map.invariants();
+        }
+        for (std::size_t k = kKeys.size(); k-- > 0;)
+        {
+            EXPECT_EQ(map.getHash().asUInt256(), kHashes[k]);
+            EXPECT_TRUE(map.delItem(kKeys[k]));
+            map.invariants();
+        }
+        EXPECT_EQ(map.getHash(), beast::kZero);
+    }
+
+    {
+        constexpr std::array kKeys{
+            uint256{"f22891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8"},
+            uint256{"b99891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8"},
+            uint256{"b92891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8"},
+            uint256{"b92881fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8"},
+            uint256{"b92791fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8"},
+            uint256{"b92691fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8"},
+            uint256{"b91891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8"},
+            uint256{"292891fe4ef6cee585fdc6fda1e09eb4d386363158ec3321b8123e5a772c6ca8"},
+        };
+
+        tests::TestNodeFamily tf{j_};
+        SHAMap map{SHAMapType::FREE, tf};
+        if (!testMode.backed)
+            map.setUnbacked();
+        for (auto const& k : kKeys)
+        {
+            map.addItem(SHAMapNodeType::TnTransactionNm, makeShamapitem(k, intToVuc(0)));
+            map.invariants();
+        }
+
+        int h = 7;
+        for (auto const& k : map)
+        {
+            EXPECT_EQ(k.key(), kKeys[h]);
+            --h;
+        }
+    }
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    BackingMode,
+    SHAMapTest,
+    ::testing::Values(kBackedMode, kUnbackedMode),
+    shamapBackingModeName);
+
+class SHAMapPathProof : public ::testing::Test
+{
+protected:
+    beast::Journal const j_{TestSink::instance()};
+};
+
+TEST_F(SHAMapPathProof, verify_proof_path)
+{
+    tests::TestNodeFamily tf{j_};
+    SHAMap map{SHAMapType::FREE, tf};
+    map.setUnbacked();
+
+    uint256 key;
+    uint256 rootHash;
+    std::vector<Blob> goodPath;
+
+    for (unsigned char c = 1; c < 100; ++c)
+    {
+        uint256 k(c);
+        map.addItem(SHAMapNodeType::TnAccountState, makeShamapitem(k, Slice{k.data(), k.size()}));
+        map.invariants();
+
+        auto root = map.getHash().asUInt256();
+        auto path = map.getProofPath(k);
+        if (!path)
+        {
+            ADD_FAILURE() << "Missing proof path";
+            return;
+        }
+        auto& proofPath = *path;
+
+        EXPECT_TRUE(map.verifyProofPath(root, k, proofPath));
+        if (c == 1)
+        {
+            // extra node
+            proofPath.insert(proofPath.begin(), proofPath.front());
+            EXPECT_FALSE(map.verifyProofPath(root, k, proofPath));
+            // wrong key
+            uint256 const wrongKey(c + 1);
+            EXPECT_FALSE(map.getProofPath(wrongKey));
+        }
+        if (c == 99)
+        {
+            key = k;
+            rootHash = root;
+            goodPath = std::move(proofPath);
+        }
+    }
+
+    // still good
+    EXPECT_TRUE(map.verifyProofPath(rootHash, key, goodPath));
+    // empty path
+    std::vector<Blob> badPath;
+    EXPECT_FALSE(map.verifyProofPath(rootHash, key, badPath));
+    // too long
+    badPath = goodPath;
+    badPath.push_back(goodPath.back());
+    EXPECT_FALSE(map.verifyProofPath(rootHash, key, badPath));
+    // bad node
+    badPath.clear();
+    badPath.emplace_back(100, 100);
+    EXPECT_FALSE(map.verifyProofPath(rootHash, key, badPath));
+    // bad node type
+    badPath.clear();
+    badPath.push_back(goodPath.front());
+    badPath.front().back()--;  // change node type
+    EXPECT_FALSE(map.verifyProofPath(rootHash, key, badPath));
+    // all inner
+    badPath.clear();
+    badPath = goodPath;
+    badPath.erase(badPath.begin());
+    EXPECT_FALSE(map.verifyProofPath(rootHash, key, badPath));
+}
+
+}  // namespace xrpl::tests
diff --git a/src/tests/libxrpl/shamap/SHAMapSync.cpp b/src/tests/libxrpl/shamap/SHAMapSync.cpp
new file mode 100644
index 0000000000..5cefbae8a1
--- /dev/null
+++ b/src/tests/libxrpl/shamap/SHAMapSync.cpp
@@ -0,0 +1,170 @@
+#include <xrpl/basics/Blob.h>
+#include <xrpl/basics/SHAMapHash.h>
+#include <xrpl/basics/Slice.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/basics/random.h>
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/beast/xor_shift_engine.h>
+#include <xrpl/protocol/Serializer.h>
+#include <xrpl/shamap/SHAMap.h>
+#include <xrpl/shamap/SHAMapItem.h>
+#include <xrpl/shamap/SHAMapMissingNode.h>
+#include <xrpl/shamap/SHAMapTreeNode.h>
+
+#include <boost/smart_ptr/intrusive_ptr.hpp>
+
+#include <gtest/gtest.h>
+#include <helpers/TestSink.h>
+#include <shamap/common.h>
+
+#include <chrono>
+#include <cstdint>
+#include <list>
+#include <utility>
+#include <vector>
+
+namespace xrpl::tests {
+
+class SHAMapSyncTest : public ::testing::Test
+{
+protected:
+    beast::Journal const j_{TestSink::instance()};
+    beast::xor_shift_engine eng_;
+
+    boost::intrusive_ptr<SHAMapItem>
+    makeRandomAS()
+    {
+        Serializer s;
+
+        for (int d = 0; d < 3; ++d)
+            s.add32(randInt<std::uint32_t>(eng_));
+        return makeShamapitem(s.getSHA512Half(), s.slice());
+    }
+
+    bool
+    confuseMap(SHAMap& map, int count)
+    {
+        // add a bunch of random states to a map, then remove them
+        // map should be the same
+        SHAMapHash const beforeHash = map.getHash();
+
+        std::list<uint256> items;
+
+        for (int i = 0; i < count; ++i)
+        {
+            auto item = makeRandomAS();
+            items.push_back(item->key());
+
+            if (!map.addItem(SHAMapNodeType::TnAccountState, item))
+            {
+                ADD_FAILURE() << "Unable to add item to map";
+                return false;
+            }
+        }
+
+        for (auto const& item : items)
+        {
+            if (!map.delItem(item))
+            {
+                ADD_FAILURE() << "Unable to remove item from map";
+                return false;
+            }
+        }
+
+        if (beforeHash != map.getHash())
+        {
+            ADD_FAILURE() << "Hashes do not match " << beforeHash << " " << map.getHash();
+            return false;
+        }
+
+        return true;
+    }
+};
+
+TEST_F(SHAMapSyncTest, sync)
+{
+    TestNodeFamily f{j_}, f2{j_};
+    SHAMap source{SHAMapType::FREE, f};
+    SHAMap destination{SHAMapType::FREE, f2};
+
+    int const items = 10000;
+    for (int i = 0; i < items; ++i)
+    {
+        source.addItem(SHAMapNodeType::TnAccountState, makeRandomAS());
+        if (i % 100 == 0)
+            source.invariants();
+    }
+
+    source.invariants();
+    ASSERT_TRUE(confuseMap(source, 500));
+    source.invariants();
+
+    source.setImmutable();
+
+    int count = 0;
+    source.visitLeaves([&count]([[maybe_unused]] auto const& item) { ++count; });
+    EXPECT_EQ(count, items);
+
+    std::vector<SHAMapMissingNode> missingNodes;
+    source.walkMap(missingNodes, 2048);
+    EXPECT_TRUE(missingNodes.empty());
+
+    destination.setSynching();
+
+    {
+        std::vector<std::pair<SHAMapNodeID, Blob>> a;
+
+        ASSERT_TRUE(source.getNodeFat(SHAMapNodeID(), a, randBool(eng_), randInt(eng_, 2)));
+
+        ASSERT_FALSE(a.empty()) << "NodeSize";
+
+        ASSERT_TRUE(
+            destination.addRootNode(source.getHash(), makeSlice(a[0].second), nullptr).isGood());
+    }
+
+    do
+    {
+        f.clock().advance(std::chrono::seconds(1));
+
+        // get the list of nodes we know we need
+        auto nodesMissing = destination.getMissingNodes(2048, nullptr);
+
+        if (nodesMissing.empty())
+            break;
+
+        // get as many nodes as possible based on this information
+        std::vector<std::pair<SHAMapNodeID, Blob>> b;
+
+        for (auto& it : nodesMissing)
+        {
+            // Keep failures fatal here because this loop is data-dependent.
+            // non-deterministic number of times and the number of tests run
+            // should be deterministic
+            if (!source.getNodeFat(it.first, b, randBool(eng_), randInt(eng_, 2)))
+                FAIL() << "Unable to fetch node";
+        }
+
+        // Keep failures fatal here because this loop is data-dependent.
+        // non-deterministic number of times and the number of tests run
+        // should be deterministic
+        if (b.empty())
+            FAIL() << "No nodes returned";
+
+        for (auto const& i : b)
+        {
+            // Keep failures fatal here because this loop is data-dependent.
+            // non-deterministic number of times and the number of tests run
+            // should be deterministic
+            if (!destination.addKnownNode(i.first, makeSlice(i.second), nullptr).isUseful())
+                FAIL() << "Known node was not useful";
+        }
+    } while (true);
+
+    destination.clearSynching();
+
+    EXPECT_TRUE(source.deepCompare(destination));
+
+    destination.invariants();
+}
+
+}  // namespace xrpl::tests
diff --git a/src/test/shamap/common.h b/src/tests/libxrpl/shamap/common.h
similarity index 89%
rename from src/test/shamap/common.h
rename to src/tests/libxrpl/shamap/common.h
index 9bef10d851..5b44f2b251 100644
--- a/src/test/shamap/common.h
+++ b/src/tests/libxrpl/shamap/common.h
@@ -4,7 +4,6 @@
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/basics/chrono.h>
 #include <xrpl/basics/contract.h>
-#include <xrpl/beast/clock/manual_clock.h>
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/config/BasicConfig.h>
 #include <xrpl/config/Constants.h>
@@ -92,13 +91,17 @@ public:
     }
 
     void
-    missingNodeAcquireBySeq(std::uint32_t refNum, uint256 const& nodeHash) override
+    missingNodeAcquireBySeq(
+        [[maybe_unused]] std::uint32_t refNum,
+        [[maybe_unused]] uint256 const& nodeHash) override
     {
         Throw<std::runtime_error>("missing node");
     }
 
     void
-    missingNodeAcquireByHash(uint256 const& refHash, std::uint32_t refNum) override
+    missingNodeAcquireByHash(
+        [[maybe_unused]] uint256 const& refHash,
+        [[maybe_unused]] std::uint32_t refNum) override
     {
         Throw<std::runtime_error>("missing node");
     }
@@ -110,7 +113,7 @@ public:
         (*tnCache_).reset();
     }
 
-    beast::ManualClock<std::chrono::steady_clock>
+    TestStopwatch&
     clock()
     {
         return clock_;
diff --git a/src/xrpld/app/ledger/TransactionMaster.h b/src/xrpld/app/ledger/TransactionMaster.h
index 5dcad09f51..6d81911510 100644
--- a/src/xrpld/app/ledger/TransactionMaster.h
+++ b/src/xrpld/app/ledger/TransactionMaster.h
@@ -68,7 +68,7 @@ public:
     canonicalize(std::shared_ptr<Transaction>* pTransaction);
 
     void
-    sweep(void);
+    sweep();
 
     TaggedCache<uint256, Transaction>&
     getCache();
diff --git a/src/xrpld/app/ledger/detail/LedgerMaster.cpp b/src/xrpld/app/ledger/detail/LedgerMaster.cpp
index 3fcac03ed5..bab0dca827 100644
--- a/src/xrpld/app/ledger/detail/LedgerMaster.cpp
+++ b/src/xrpld/app/ledger/detail/LedgerMaster.cpp
@@ -137,7 +137,7 @@ LedgerMaster::LedgerMaster(
           std::chrono::seconds{45},
           stopwatch,
           app_.getJournal("TaggedCache"))
-    , stats_(std::bind(&LedgerMaster::collectMetrics, this), collector)
+    , stats_([this] { collectMetrics(); }, collector)
 {
 }
 
diff --git a/src/xrpld/app/ledger/detail/TransactionMaster.cpp b/src/xrpld/app/ledger/detail/TransactionMaster.cpp
index 129681b906..ac2aa1aabe 100644
--- a/src/xrpld/app/ledger/detail/TransactionMaster.cpp
+++ b/src/xrpld/app/ledger/detail/TransactionMaster.cpp
@@ -152,7 +152,7 @@ TransactionMaster::canonicalize(std::shared_ptr<Transaction>* pTransaction)
 }
 
 void
-TransactionMaster::sweep(void)
+TransactionMaster::sweep()
 {
     cache_.sweep();
 }
diff --git a/src/xrpld/app/misc/NetworkOPs.cpp b/src/xrpld/app/misc/NetworkOPs.cpp
index d1f794b74d..4d40247a29 100644
--- a/src/xrpld/app/misc/NetworkOPs.cpp
+++ b/src/xrpld/app/misc/NetworkOPs.cpp
@@ -330,7 +330,7 @@ public:
         , jobQueue_(jobQueue)
         , standalone_(standalone)
         , minPeerCount_(startValid ? 0 : minPeerCount)
-        , stats_(std::bind(&NetworkOPsImp::collectMetrics, this), collector)
+        , stats_([this] { collectMetrics(); }, collector)
     {
     }
 
diff --git a/src/xrpld/app/misc/SHAMapStoreImp.cpp b/src/xrpld/app/misc/SHAMapStoreImp.cpp
index 0389130f7a..0e0099cdbf 100644
--- a/src/xrpld/app/misc/SHAMapStoreImp.cpp
+++ b/src/xrpld/app/misc/SHAMapStoreImp.cpp
@@ -331,11 +331,9 @@ SHAMapStoreImp::run()
             try
             {
                 validatedLedger->stateMap().snapShot(false)->visitNodes(
-                    std::bind(
-                        &SHAMapStoreImp::copyNode,
-                        this,
-                        std::ref(nodeCount),
-                        std::placeholders::_1));
+                    [this, &nodeCount](SHAMapTreeNode const& node) {
+                        return copyNode(nodeCount, node);
+                    });
             }
             catch (SHAMapMissingNode const& e)
             {
diff --git a/src/xrpld/app/misc/detail/WorkBase.h b/src/xrpld/app/misc/detail/WorkBase.h
index 5f5fdd28b7..73e5081036 100644
--- a/src/xrpld/app/misc/detail/WorkBase.h
+++ b/src/xrpld/app/misc/detail/WorkBase.h
@@ -12,6 +12,7 @@
 #include <boost/beast/http/read.hpp>
 #include <boost/beast/http/write.hpp>
 
+#include <cstddef>
 #include <functional>
 #include <string>
 #include <utility>
@@ -138,9 +139,9 @@ WorkBase<Impl>::run()
     if (!strand_.running_in_this_thread())
     {
         return boost::asio::post(
-            ios_,
-            boost::asio::bind_executor(
-                strand_, std::bind(&WorkBase::run, impl().shared_from_this())));
+            ios_, boost::asio::bind_executor(strand_, [self = impl().shared_from_this()] {
+                self->run();
+            }));
     }
 
     resolver_.async_resolve(
@@ -148,11 +149,9 @@ WorkBase<Impl>::run()
         port_,
         boost::asio::bind_executor(
             strand_,
-            std::bind(
-                &WorkBase::onResolve,
-                impl().shared_from_this(),
-                std::placeholders::_1,
-                std::placeholders::_2)));
+            [self = impl().shared_from_this()](error_code const& ec, results_type results) {
+                self->onResolve(ec, results);
+            }));
 }
 
 template <class Impl>
@@ -165,7 +164,7 @@ WorkBase<Impl>::cancel()
             ios_,
 
             boost::asio::bind_executor(
-                strand_, std::bind(&WorkBase::cancel, impl().shared_from_this())));
+                strand_, [self = impl().shared_from_this()] { self->cancel(); }));
     }
 
     error_code ec;
@@ -196,11 +195,12 @@ WorkBase<Impl>::onResolve(error_code const& ec, results_type results)
         results,
         boost::asio::bind_executor(
             strand_,
-            std::bind(
-                &WorkBase::onConnect,
-                impl().shared_from_this(),
-                std::placeholders::_1,
-                std::placeholders::_2)));
+            [self = impl().shared_from_this()](
+                error_code const& ec, endpoint_type const& endpoint) {
+                // Call the base-class overload explicitly: the derived Impl
+                // hides it with its own single-argument onConnect(ec).
+                self->WorkBase::onConnect(ec, endpoint);
+            }));
 }
 
 template <class Impl>
@@ -229,8 +229,9 @@ WorkBase<Impl>::onStart()
         impl().stream(),
         req_,
         boost::asio::bind_executor(
-            strand_,
-            std::bind(&WorkBase::onRequest, impl().shared_from_this(), std::placeholders::_1)));
+            strand_, [self = impl().shared_from_this()](error_code const& ec, std::size_t) {
+                self->onRequest(ec);
+            }));
 }
 
 template <class Impl>
@@ -245,8 +246,9 @@ WorkBase<Impl>::onRequest(error_code const& ec)
         readBuf_,
         res_,
         boost::asio::bind_executor(
-            strand_,
-            std::bind(&WorkBase::onResponse, impl().shared_from_this(), std::placeholders::_1)));
+            strand_, [self = impl().shared_from_this()](error_code const& ec, std::size_t) {
+                self->onResponse(ec);
+            }));
 }
 
 template <class Impl>
diff --git a/src/xrpld/app/misc/detail/WorkFile.h b/src/xrpld/app/misc/detail/WorkFile.h
index 2fc7ab952d..eb42d14db4 100644
--- a/src/xrpld/app/misc/detail/WorkFile.h
+++ b/src/xrpld/app/misc/detail/WorkFile.h
@@ -63,9 +63,9 @@ WorkFile::run()
 {
     if (!strand_.running_in_this_thread())
     {
-        boost::asio::post(
-            ios_,
-            boost::asio::bind_executor(strand_, std::bind(&WorkFile::run, shared_from_this())));
+        boost::asio::post(ios_, boost::asio::bind_executor(strand_, [self = shared_from_this()] {
+                              self->run();
+                          }));
         return;
     }
 
diff --git a/src/xrpld/app/misc/detail/WorkSSL.cpp b/src/xrpld/app/misc/detail/WorkSSL.cpp
index e1b864e81f..e8d24b55d6 100644
--- a/src/xrpld/app/misc/detail/WorkSSL.cpp
+++ b/src/xrpld/app/misc/detail/WorkSSL.cpp
@@ -12,7 +12,6 @@
 #include <boost/asio/ssl/stream_base.hpp>
 #include <boost/format/free_funcs.hpp>
 
-#include <functional>
 #include <stdexcept>
 #include <string>
 
@@ -55,7 +54,7 @@ WorkSSL::onConnect(error_code const& ec)
     stream_.async_handshake(
         boost::asio::ssl::stream_base::client,
         boost::asio::bind_executor(
-            strand_, std::bind(&WorkSSL::onHandshake, shared_from_this(), std::placeholders::_1)));
+            strand_, [self = shared_from_this()](error_code const& ec) { self->onHandshake(ec); }));
 }
 
 void
diff --git a/src/xrpld/app/rdb/backend/detail/SQLiteDatabase.cpp b/src/xrpld/app/rdb/backend/detail/SQLiteDatabase.cpp
index fd1298516f..338a3a33df 100644
--- a/src/xrpld/app/rdb/backend/detail/SQLiteDatabase.cpp
+++ b/src/xrpld/app/rdb/backend/detail/SQLiteDatabase.cpp
@@ -421,8 +421,9 @@ SQLiteDatabase::oldestAccountTxPage(AccountTxPageOptions const& options)
         return {};
 
     static std::uint32_t const kPageLength(200);
-    auto onUnsavedLedger =
-        std::bind(saveLedgerAsync, std::ref(registry_.get().getApp()), std::placeholders::_1);
+    auto onUnsavedLedger = [&app = registry_.get().getApp()](std::uint32_t seq) {
+        saveLedgerAsync(app, seq);
+    };
     AccountTxs ret;
     auto onTransaction = [&ret, &app = registry_.get().getApp()](
                              std::uint32_t ledgerIndex,
@@ -451,8 +452,9 @@ SQLiteDatabase::newestAccountTxPage(AccountTxPageOptions const& options)
         return {};
 
     static std::uint32_t const kPageLength(200);
-    auto onUnsavedLedger =
-        std::bind(saveLedgerAsync, std::ref(registry_.get().getApp()), std::placeholders::_1);
+    auto onUnsavedLedger = [&app = registry_.get().getApp()](std::uint32_t seq) {
+        saveLedgerAsync(app, seq);
+    };
     AccountTxs ret;
     auto onTransaction = [&ret, &app = registry_.get().getApp()](
                              std::uint32_t ledgerIndex,
@@ -481,8 +483,9 @@ SQLiteDatabase::oldestAccountTxPageB(AccountTxPageOptions const& options)
         return {};
 
     static std::uint32_t const kPageLength(500);
-    auto onUnsavedLedger =
-        std::bind(saveLedgerAsync, std::ref(registry_.get().getApp()), std::placeholders::_1);
+    auto onUnsavedLedger = [&app = registry_.get().getApp()](std::uint32_t seq) {
+        saveLedgerAsync(app, seq);
+    };
     MetaTxsList ret;
     auto onTransaction =
         [&ret](
@@ -509,8 +512,9 @@ SQLiteDatabase::newestAccountTxPageB(AccountTxPageOptions const& options)
         return {};
 
     static std::uint32_t const kPageLength(500);
-    auto onUnsavedLedger =
-        std::bind(saveLedgerAsync, std::ref(registry_.get().getApp()), std::placeholders::_1);
+    auto onUnsavedLedger = [&app = registry_.get().getApp()](std::uint32_t seq) {
+        saveLedgerAsync(app, seq);
+    };
     MetaTxsList ret;
     auto onTransaction =
         [&ret](
diff --git a/src/xrpld/app/rdb/detail/PeerFinder.cpp b/src/xrpld/app/rdb/detail/PeerFinder.cpp
index c40e3e42c6..abdcd1c61a 100644
--- a/src/xrpld/app/rdb/detail/PeerFinder.cpp
+++ b/src/xrpld/app/rdb/detail/PeerFinder.cpp
@@ -147,10 +147,10 @@ updatePeerFinderDB(soci::session& session, int currentSchemaVersion, beast::Jour
             s.reserve(list.size());
             valence.reserve(list.size());
 
-            for (auto iter(list.cbegin()); iter != list.cend(); ++iter)
+            for (auto const& entry : list)
             {
-                s.emplace_back(to_string(iter->endpoint));
-                valence.emplace_back(iter->valence);
+                s.emplace_back(to_string(entry.endpoint));
+                valence.emplace_back(entry.valence);
             }
 
             session << "INSERT INTO PeerFinder_BootstrapCache_Next ( "
diff --git a/src/xrpld/core/detail/Config.cpp b/src/xrpld/core/detail/Config.cpp
index 07c780118a..0706163ab1 100644
--- a/src/xrpld/core/detail/Config.cpp
+++ b/src/xrpld/core/detail/Config.cpp
@@ -98,7 +98,7 @@ getMemorySize()
     std::int64_t ram = 0;
     size_t size = sizeof(ram);
 
-    if (sysctl(mib, 2, &ram, &size, NULL, 0) == 0)
+    if (sysctl(mib, 2, &ram, &size, nullptr, 0) == 0)
         return static_cast<std::uint64_t>(ram);
 
     return 0;
@@ -917,7 +917,7 @@ Config::loadFromString(std::string const& fileContents)
     if (getSingleSection(secConfig, Sections::kAmendmentMajorityTime, strTemp, j_))
     {
         using namespace std::chrono;
-        boost::regex const re("^\\s*(\\d+)\\s*(minutes|hours|days|weeks)\\s*(\\s+.*)?$");
+        boost::regex const re(R"(^\s*(\d+)\s*(minutes|hours|days|weeks)\s*(\s+.*)?$)");
         boost::smatch match;
         if (!boost::regex_match(strTemp, match, re))
         {
diff --git a/src/xrpld/overlay/detail/ConnectAttempt.cpp b/src/xrpld/overlay/detail/ConnectAttempt.cpp
index 295f4f5497..064b4ecd3e 100644
--- a/src/xrpld/overlay/detail/ConnectAttempt.cpp
+++ b/src/xrpld/overlay/detail/ConnectAttempt.cpp
@@ -35,8 +35,8 @@
 #include <boost/system/system_error.hpp>
 
 #include <chrono>
+#include <cstddef>
 #include <exception>
-#include <functional>
 #include <memory>
 #include <optional>
 #include <string>
@@ -86,7 +86,7 @@ ConnectAttempt::stop()
 {
     if (!strand_.running_in_this_thread())
     {
-        boost::asio::post(strand_, std::bind(&ConnectAttempt::stop, shared_from_this()));
+        boost::asio::post(strand_, [self = shared_from_this()] { self->stop(); });
         return;
     }
     if (socket_.is_open())
@@ -104,8 +104,7 @@ ConnectAttempt::run()
     stream_.next_layer().async_connect(
         remoteEndpoint_,
         boost::asio::bind_executor(
-            strand_,
-            std::bind(&ConnectAttempt::onConnect, shared_from_this(), std::placeholders::_1)));
+            strand_, [self = shared_from_this()](error_code const& ec) { self->onConnect(ec); }));
 }
 
 //------------------------------------------------------------------------------
@@ -160,8 +159,7 @@ ConnectAttempt::setTimer()
 
     timer_.async_wait(
         boost::asio::bind_executor(
-            strand_,
-            std::bind(&ConnectAttempt::onTimer, shared_from_this(), std::placeholders::_1)));
+            strand_, [self = shared_from_this()](error_code const& ec) { self->onTimer(ec); }));
 }
 
 void
@@ -228,8 +226,7 @@ ConnectAttempt::onConnect(error_code ec)
     stream_.async_handshake(
         boost::asio::ssl::stream_base::client,
         boost::asio::bind_executor(
-            strand_,
-            std::bind(&ConnectAttempt::onHandshake, shared_from_this(), std::placeholders::_1)));
+            strand_, [self = shared_from_this()](error_code const& ec) { self->onHandshake(ec); }));
 }
 
 void
@@ -290,7 +287,7 @@ ConnectAttempt::onHandshake(error_code ec)
         req_,
         boost::asio::bind_executor(
             strand_,
-            std::bind(&ConnectAttempt::onWrite, shared_from_this(), std::placeholders::_1)));
+            [self = shared_from_this()](error_code const& ec, std::size_t) { self->onWrite(ec); }));
 }
 
 void
@@ -316,7 +313,7 @@ ConnectAttempt::onWrite(error_code ec)
         response_,
         boost::asio::bind_executor(
             strand_,
-            std::bind(&ConnectAttempt::onRead, shared_from_this(), std::placeholders::_1)));
+            [self = shared_from_this()](error_code const& ec, std::size_t) { self->onRead(ec); }));
 }
 
 void
@@ -339,8 +336,7 @@ ConnectAttempt::onRead(error_code ec)
             stream_.async_shutdown(
                 boost::asio::bind_executor(
                     strand_,
-                    std::bind(
-                        &ConnectAttempt::onShutdown, shared_from_this(), std::placeholders::_1)));
+                    [self = shared_from_this()](error_code const& ec) { self->onShutdown(ec); }));
             return;
         }
 
diff --git a/src/xrpld/overlay/detail/OverlayImpl.cpp b/src/xrpld/overlay/detail/OverlayImpl.cpp
index 89c7dfe5eb..b7af3b6ace 100644
--- a/src/xrpld/overlay/detail/OverlayImpl.cpp
+++ b/src/xrpld/overlay/detail/OverlayImpl.cpp
@@ -133,7 +133,7 @@ OverlayImpl::Timer::asyncWait()
     timer.async_wait(
         boost::asio::bind_executor(
             overlay_.strand_,
-            std::bind(&Timer::onTimer, shared_from_this(), std::placeholders::_1)));
+            [self = shared_from_this()](error_code const& ec) { self->onTimer(ec); }));
 }
 
 void
@@ -190,7 +190,7 @@ OverlayImpl::OverlayImpl(
     , nextId_(1)
     , slots_(app, *this, app.config())
     , stats_(
-          std::bind(&OverlayImpl::collectMetrics, this),
+          [this] { collectMetrics(); },
           collector,
           [counts = traffic_.getCounts(), collector]() {
               std::unordered_map<TrafficCount::Category, TrafficGauges> ret;
@@ -593,7 +593,7 @@ OverlayImpl::start()
 void
 OverlayImpl::stop()
 {
-    boost::asio::dispatch(strand_, std::bind(&OverlayImpl::stopChildren, this));
+    boost::asio::dispatch(strand_, [this] { stopChildren(); });
     {
         std::unique_lock<decltype(mutex_)> lock(mutex_);
         cond_.wait(lock, [this] { return list_.empty(); });
@@ -1490,7 +1490,7 @@ OverlayImpl::deletePeer(Peer::id_t id)
 {
     if (!strand_.running_in_this_thread())
     {
-        post(strand_, std::bind(&OverlayImpl::deletePeer, this, id));
+        post(strand_, [this, id] { deletePeer(id); });
         return;
     }
 
@@ -1502,7 +1502,7 @@ OverlayImpl::deleteIdlePeers()
 {
     if (!strand_.running_in_this_thread())
     {
-        post(strand_, std::bind(&OverlayImpl::deleteIdlePeers, this));
+        post(strand_, [this] { deleteIdlePeers(); });
         return;
     }
 
diff --git a/src/xrpld/overlay/detail/OverlayImpl.h b/src/xrpld/overlay/detail/OverlayImpl.h
index 7db32c0d23..83d5a81a89 100644
--- a/src/xrpld/overlay/detail/OverlayImpl.h
+++ b/src/xrpld/overlay/detail/OverlayImpl.h
@@ -427,7 +427,7 @@ public:
     addTxMetrics(Args... args)
     {
         if (!strand_.running_in_this_thread())
-            return post(strand_, std::bind(&OverlayImpl::addTxMetrics<Args...>, this, args...));
+            return post(strand_, [this, args...] { addTxMetrics(args...); });
 
         txMetrics_.addMetrics(args...);
     }
diff --git a/src/xrpld/overlay/detail/PeerImp.cpp b/src/xrpld/overlay/detail/PeerImp.cpp
index 83e4d9c851..4e42d46f46 100644
--- a/src/xrpld/overlay/detail/PeerImp.cpp
+++ b/src/xrpld/overlay/detail/PeerImp.cpp
@@ -321,9 +321,9 @@ PeerImp::send(std::shared_ptr<Message> const& m)
             self->stream_,
             boost::asio::buffer(self->sendQueue_.front()->getBuffer(self->compressionEnabled_)),
             bind_executor(
-                self->strand_,
-                std::bind(
-                    &PeerImp::onWriteMessage, self, std::placeholders::_1, std::placeholders::_2)));
+                self->strand_, [self](error_code const& ec, std::size_t bytesTransferred) {
+                    self->onWriteMessage(ec, bytesTransferred);
+                }));
     });
 }
 
@@ -650,7 +650,7 @@ PeerImp::gracefulClose()
         return;
     setTimer();
     stream_.async_shutdown(bind_executor(
-        strand_, std::bind(&PeerImp::onShutdown, shared_from_this(), std::placeholders::_1)));
+        strand_, [self = shared_from_this()](error_code const& ec) { self->onShutdown(ec); }));
 }
 
 void
@@ -666,7 +666,7 @@ PeerImp::setTimer()
         return;
     }
     timer_.async_wait(bind_executor(
-        strand_, std::bind(&PeerImp::onTimer, shared_from_this(), std::placeholders::_1)));
+        strand_, [self = shared_from_this()](error_code const& ec) { self->onTimer(ec); }));
 }
 
 // convenience for ignoring the error code
@@ -975,11 +975,9 @@ PeerImp::onReadMessage(error_code ec, std::size_t bytesTransferred)
         readBuffer_.prepare(std::max(Tuning::kReadBufferBytes, hint)),
         bind_executor(
             strand_,
-            std::bind(
-                &PeerImp::onReadMessage,
-                shared_from_this(),
-                std::placeholders::_1,
-                std::placeholders::_2)));
+            [self = shared_from_this()](error_code const& ec, std::size_t bytesTransferred) {
+                self->onReadMessage(ec, bytesTransferred);
+            }));
 }
 
 void
@@ -1014,18 +1012,16 @@ PeerImp::onWriteMessage(error_code ec, std::size_t bytesTransferred)
             boost::asio::buffer(sendQueue_.front()->getBuffer(compressionEnabled_)),
             bind_executor(
                 strand_,
-                std::bind(
-                    &PeerImp::onWriteMessage,
-                    shared_from_this(),
-                    std::placeholders::_1,
-                    std::placeholders::_2)));
+                [self = shared_from_this()](error_code const& ec, std::size_t bytesTransferred) {
+                    self->onWriteMessage(ec, bytesTransferred);
+                }));
         return;
     }
 
     if (gracefulClose_)
     {
         stream_.async_shutdown(bind_executor(
-            strand_, std::bind(&PeerImp::onShutdown, shared_from_this(), std::placeholders::_1)));
+            strand_, [self = shared_from_this()](error_code const& ec) { self->onShutdown(ec); }));
         return;
     }
 }
diff --git a/src/xrpld/overlay/detail/PeerImp.h b/src/xrpld/overlay/detail/PeerImp.h
index 4a96f9a6e6..e9ef948d48 100644
--- a/src/xrpld/overlay/detail/PeerImp.h
+++ b/src/xrpld/overlay/detail/PeerImp.h
@@ -322,12 +322,11 @@ public:
     removeTxQueue(uint256 const& hash) override;
 
     /** Send a set of PeerFinder endpoints as a protocol message. */
-    template <
-        class FwdIt,
-        class = std::enable_if_t<
-            std::is_same_v<typename std::iterator_traits<FwdIt>::value_type, PeerFinder::Endpoint>>>
+    template <class FwdIt>
     void
-    sendEndpoints(FwdIt first, FwdIt last);
+    sendEndpoints(FwdIt first, FwdIt last)
+        requires(
+            std::is_same_v<typename std::iterator_traits<FwdIt>::value_type, PeerFinder::Endpoint>);
 
     beast::IP::Endpoint
     getRemoteAddress() const override
@@ -787,9 +786,10 @@ PeerImp::PeerImp(
         << id_;
 }
 
-template <class FwdIt, class>
+template <class FwdIt>
 void
 PeerImp::sendEndpoints(FwdIt first, FwdIt last)
+    requires(std::is_same_v<typename std::iterator_traits<FwdIt>::value_type, PeerFinder::Endpoint>)
 {
     protocol::TMEndpoints tm;
 
diff --git a/src/xrpld/overlay/detail/ProtocolMessage.h b/src/xrpld/overlay/detail/ProtocolMessage.h
index da418f8e82..156fcfc104 100644
--- a/src/xrpld/overlay/detail/ProtocolMessage.h
+++ b/src/xrpld/overlay/detail/ProtocolMessage.h
@@ -237,12 +237,10 @@ parseMessageHeader(boost::system::error_code& ec, BufferSequence const& bufs, st
     return std::nullopt;
 }
 
-template <
-    class T,
-    class Buffers,
-    class = std::enable_if_t<std::is_base_of_v<::google::protobuf::Message, T>>>
+template <class T, class Buffers>
 std::shared_ptr<T>
 parseMessageContent(MessageHeader const& header, Buffers const& buffers)
+    requires(std::is_base_of_v<::google::protobuf::Message, T>)
 {
     auto m = std::make_shared<T>();
 
@@ -272,13 +270,10 @@ parseMessageContent(MessageHeader const& header, Buffers const& buffers)
     return m;
 }
 
-template <
-    class T,
-    class Buffers,
-    class Handler,
-    class = std::enable_if_t<std::is_base_of_v<::google::protobuf::Message, T>>>
+template <class T, class Buffers, class Handler>
 bool
 invoke(MessageHeader const& header, Buffers const& buffers, Handler& handler)
+    requires(std::is_base_of_v<::google::protobuf::Message, T>)
 {
     auto const m = parseMessageContent<T>(header, buffers);
     if (!m)
diff --git a/src/xrpld/peerfinder/detail/Bootcache.h b/src/xrpld/peerfinder/detail/Bootcache.h
index 5384bb356a..cee03fa322 100644
--- a/src/xrpld/peerfinder/detail/Bootcache.h
+++ b/src/xrpld/peerfinder/detail/Bootcache.h
@@ -3,7 +3,6 @@
 #include <xrpld/peerfinder/PeerfinderManager.h>
 #include <xrpld/peerfinder/detail/Store.h>
 
-#include <xrpl/basics/comparators.h>
 #include <xrpl/beast/net/IPEndpoint.h>
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/beast/utility/PropertyStream.h>
@@ -13,6 +12,8 @@
 #include <boost/bimap/unordered_set_of.hpp>
 #include <boost/iterator/transform_iterator.hpp>
 
+#include <functional>
+
 namespace xrpl::PeerFinder {
 
 /** Stores IP addresses useful for gaining initial connections.
@@ -62,11 +63,9 @@ private:
         int valence_;
     };
 
-    using left_t = boost::bimaps::unordered_set_of<
-        beast::IP::Endpoint,
-        boost::hash<beast::IP::Endpoint>,
-        xrpl::equal_to<beast::IP::Endpoint>>;
-    using right_t = boost::bimaps::multiset_of<Entry, xrpl::less<Entry>>;
+    using left_t = boost::bimaps::
+        unordered_set_of<beast::IP::Endpoint, boost::hash<beast::IP::Endpoint>, std::equal_to<>>;
+    using right_t = boost::bimaps::multiset_of<Entry, std::less<>>;
     using map_type = boost::bimap<left_t, right_t>;
     using value_type = map_type::value_type;
 
diff --git a/src/xrpld/peerfinder/detail/Checker.h b/src/xrpld/peerfinder/detail/Checker.h
index 20687448df..208bad390c 100644
--- a/src/xrpld/peerfinder/detail/Checker.h
+++ b/src/xrpld/peerfinder/detail/Checker.h
@@ -8,7 +8,6 @@
 #include <boost/intrusive/list.hpp>
 
 #include <condition_variable>
-#include <functional>
 #include <memory>
 #include <mutex>
 
@@ -183,7 +182,7 @@ Checker<Protocol>::asyncConnect(beast::IP::Endpoint const& endpoint, Handler&& h
     }
     op->socket.async_connect(
         beast::IPAddressConversion::toAsioEndpoint(endpoint),
-        std::bind(&BasicAsyncOp::operator(), op, std::placeholders::_1));
+        [op](error_code const& ec) { (*op)(ec); });
 }
 
 template <class Protocol>
diff --git a/src/xrpld/peerfinder/detail/Logic.h b/src/xrpld/peerfinder/detail/Logic.h
index 7d10f7f516..8ea348f560 100644
--- a/src/xrpld/peerfinder/detail/Logic.h
+++ b/src/xrpld/peerfinder/detail/Logic.h
@@ -802,12 +802,10 @@ public:
                     //
                     checker.asyncConnect(
                         ep.address,
-                        std::bind(
-                            &Logic::checkComplete,
-                            this,
-                            slot->remoteEndpoint(),
-                            ep.address,
-                            std::placeholders::_1));
+                        [this, remoteAddress = slot->remoteEndpoint(), checkedAddress = ep.address](
+                            boost::system::error_code const& ec) {
+                            checkComplete(remoteAddress, checkedAddress, ec);
+                        });
 
                     // Note that we simply discard the first Endpoint
                     // that the neighbor sends when we perform the
diff --git a/src/xrpld/peerfinder/detail/PeerfinderManager.cpp b/src/xrpld/peerfinder/detail/PeerfinderManager.cpp
index 9dbedfe4f1..2727a03013 100644
--- a/src/xrpld/peerfinder/detail/PeerfinderManager.cpp
+++ b/src/xrpld/peerfinder/detail/PeerfinderManager.cpp
@@ -20,7 +20,6 @@
 #include <boost/asio/io_context.hpp>
 #include <boost/asio/ip/tcp.hpp>
 
-#include <functional>
 #include <memory>
 #include <mutex>
 #include <optional>
@@ -61,7 +60,7 @@ public:
         , checker_(io_context_)
         , logic_(clock, store_, checker_, journal)
         , config_(config)
-        , stats_(std::bind(&ManagerImp::collectMetrics, this), collector)
+        , stats_([this] { collectMetrics(); }, collector)
     {
     }
 
diff --git a/src/xrpld/peerfinder/detail/SourceStrings.cpp b/src/xrpld/peerfinder/detail/SourceStrings.cpp
index 61a3e0c021..7b28db4306 100644
--- a/src/xrpld/peerfinder/detail/SourceStrings.cpp
+++ b/src/xrpld/peerfinder/detail/SourceStrings.cpp
@@ -32,11 +32,11 @@ public:
     {
         results.addresses.resize(0);
         results.addresses.reserve(strings_.size());
-        for (int i = 0; i < strings_.size(); ++i)
+        for (auto const& str : strings_)
         {
-            beast::IP::Endpoint ep(beast::IP::Endpoint::fromString(strings_[i]));
+            beast::IP::Endpoint ep(beast::IP::Endpoint::fromString(str));
             if (isUnspecified(ep))
-                ep = beast::IP::Endpoint::fromString(strings_[i]);
+                ep = beast::IP::Endpoint::fromString(str);
             if (!isUnspecified(ep))
                 results.addresses.push_back(ep);
         }
diff --git a/src/xrpld/rpc/Status.h b/src/xrpld/rpc/Status.h
index 4f15ab0242..ff77f2ace7 100644
--- a/src/xrpld/rpc/Status.h
+++ b/src/xrpld/rpc/Status.h
@@ -33,9 +33,11 @@ public:
 
     Status() = default;
 
-    // The enable_if allows only integers (not enums).  Prevents enum narrowing.
-    template <typename T, typename = std::enable_if_t<std::is_integral_v<T>>>
-    Status(T code, Strings d = {}) : code_(code), messages_(std::move(d))
+    // The constraint allows only integers (not enums).  Prevents enum narrowing.
+    template <typename T>
+    Status(T code, Strings d = {})
+        requires(std::is_integral_v<T>)
+        : code_(code), messages_(std::move(d))
     {
     }
 
diff --git a/src/xrpld/rpc/detail/Pathfinder.cpp b/src/xrpld/rpc/detail/Pathfinder.cpp
index fc788dea7d..5b7f1415a2 100644
--- a/src/xrpld/rpc/detail/Pathfinder.cpp
+++ b/src/xrpld/rpc/detail/Pathfinder.cpp
@@ -1158,11 +1158,10 @@ Pathfinder::addLink(
                 {
                     std::ranges::sort(
                         candidates,
-                        std::bind(
-                            compareAccountCandidate,
-                            ledger_->seq(),
-                            std::placeholders::_1,
-                            std::placeholders::_2));
+                        [seq = ledger_->seq()](
+                            AccountCandidate const& first, AccountCandidate const& second) {
+                            return compareAccountCandidate(seq, first, second);
+                        });
 
                     int count = candidates.size();
                     // allow more paths from source
diff --git a/src/xrpld/rpc/detail/RPCCall.cpp b/src/xrpld/rpc/detail/RPCCall.cpp
index 123b9fc7a5..af5677008d 100644
--- a/src/xrpld/rpc/detail/RPCCall.cpp
+++ b/src/xrpld/rpc/detail/RPCCall.cpp
@@ -1745,7 +1745,9 @@ rpcClient(
                     static_cast<int>(setup.client.secure) != 0,  // Use SSL
                     config.quiet(),
                     logs,
-                    std::bind(RPCCallImp::callRPCHandler, &jvOutput, std::placeholders::_1),
+                    [&jvOutput](json::Value const& jvInput) {
+                        RPCCallImp::callRPCHandler(&jvOutput, jvInput);
+                    },
                     headers);
                 isService.run();  // This blocks until there are no more
                                   // outstanding async calls.
@@ -1870,24 +1872,16 @@ fromNetwork(
         ioContext,
         strIp,
         iPort,
-        std::bind(
-            &RPCCallImp::onRequest,
-            strMethod,
-            jvParams,
-            headers,
-            strPath,
-            std::placeholders::_1,
-            std::placeholders::_2,
-            j),
+        [strMethod, jvParams, headers, strPath, j](
+            boost::asio::streambuf& sb, std::string const& strHost) {
+            RPCCallImp::onRequest(strMethod, jvParams, headers, strPath, sb, strHost, j);
+        },
         kRpcReplyMaxBytes,
         kRpcWebhookTimeout,
-        std::bind(
-            &RPCCallImp::onResponse,
-            callbackFuncP,
-            std::placeholders::_1,
-            std::placeholders::_2,
-            std::placeholders::_3,
-            j),
+        [callbackFuncP, j](
+            boost::system::error_code const& ecResult, int iStatus, std::string const& strData) {
+            return RPCCallImp::onResponse(callbackFuncP, ecResult, iStatus, strData, j);
+        },
         j);
 }
 
diff --git a/src/xrpld/rpc/handlers/account/GatewayBalances.cpp b/src/xrpld/rpc/handlers/account/GatewayBalances.cpp
index bd1681172c..a6730c8e2b 100644
--- a/src/xrpld/rpc/handlers/account/GatewayBalances.cpp
+++ b/src/xrpld/rpc/handlers/account/GatewayBalances.cpp
@@ -106,8 +106,8 @@ doGatewayBalances(RPC::JsonContext& context)
         // null is treated as a valid 0-sized array of hotwallet
         if (hw.isArrayOrNull())
         {
-            for (unsigned i = 0; i < hw.size(); ++i)
-                valid &= addHotWallet(hw[i]);
+            for (auto const& wallet : hw)
+                valid &= addHotWallet(wallet);
         }
         else if (hw.isString())
         {
diff --git a/src/xrpld/rpc/handlers/orderbook/GetAggregatePrice.cpp b/src/xrpld/rpc/handlers/orderbook/GetAggregatePrice.cpp
index c1c8712655..d2f596ed8e 100644
--- a/src/xrpld/rpc/handlers/orderbook/GetAggregatePrice.cpp
+++ b/src/xrpld/rpc/handlers/orderbook/GetAggregatePrice.cpp
@@ -40,8 +40,7 @@ namespace xrpl {
 
 using namespace boost::bimaps;
 // sorted descending by lastUpdateTime, ascending by AssetPrice
-using Prices =
-    bimap<multiset_of<std::uint32_t, std::greater<std::uint32_t>>, multiset_of<STAmount>>;
+using Prices = bimap<multiset_of<std::uint32_t, std::greater<>>, multiset_of<STAmount>>;
 
 /** Calls callback "f" on the ledger-object sle and up to three previous
  * metadata objects. Stops early if the callback returns true.