Address comments

.clang-tidy

@@ -97,21 +97,9 @@ Checks: "-*,
   misc-throw-by-value-catch-by-reference,
   misc-unused-alias-decls,
   misc-unused-using-decls,
-  modernize-concat-nested-namespaces,
+  modernize-deprecated-headers,
   modernize-make-shared,
   modernize-make-unique,
-  modernize-pass-by-value,
-  modernize-type-traits,
-  modernize-use-designated-initializers,
-  modernize-use-emplace,
-  modernize-use-equals-default,
-  modernize-use-equals-delete,
-  modernize-use-override,
-  modernize-use-ranges,
-  modernize-use-starts-ends-with,
-  modernize-use-std-numbers,
-  modernize-use-using,
-  modernize-deprecated-headers,
   llvm-namespace-comment,
   performance-faster-string-find,
   performance-for-range-copy,
@@ -153,6 +141,19 @@ Checks: "-*,
 # readability-inconsistent-declaration-parameter-name, # in this codebase this check will break a lot of arg names
 # readability-static-accessed-through-instance,        # this check is probably unnecessary. it makes the code less readable
 # readability-identifier-naming,                       # https://github.com/XRPLF/rippled/pull/6571
+#
+# modernize-concat-nested-namespaces,
+# modernize-pass-by-value,
+# modernize-type-traits,
+# modernize-use-designated-initializers,
+# modernize-use-emplace,
+# modernize-use-equals-default,
+# modernize-use-equals-delete,
+# modernize-use-override,
+# modernize-use-ranges,
+# modernize-use-starts-ends-with,
+# modernize-use-std-numbers,
+# modernize-use-using,
 # ---
 #
 CheckOptions:

.github/workflows/reusable-clang-tidy-files.yml

@@ -90,21 +90,8 @@ jobs:
           path: clang-tidy-output.txt
           retention-days: 30
 
-      - name: Generate git diff
-        if: ${{ steps.run_clang_tidy.outcome != 'success' }}
-        run: |
-          git diff | tee clang-tidy-git-diff.txt
-
-      - name: Upload clang-tidy diff output
-        if: ${{ github.event.repository.visibility == 'public' && steps.run_clang_tidy.outcome != 'success' }}
-        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
-        with:
-          name: clang-tidy-git-diff
-          path: clang-tidy-git-diff.txt
-          retention-days: 30
-
       - name: Create an issue
-        if: ${{ steps.run_clang_tidy.outcome != 'success' && inputs.create_issue_on_failure }}
+        if: steps.run_clang_tidy.outcome != 'success' && inputs.create_issue_on_failure
         id: create_issue
         shell: bash
         env:
@@ -169,7 +156,7 @@ jobs:
           rm -f create_issue.log issue.md clang-tidy-output.txt
 
       - name: Fail the workflow if clang-tidy failed
-        if: ${{ steps.run_clang_tidy.outcome != 'success' }}
+        if: steps.run_clang_tidy.outcome != 'success'
         run: |
           echo "Clang-tidy check failed!"
           exit 1

cfg/xrpld-example.cfg

@@ -1416,12 +1416,6 @@
 #       in this section to a comma-separated list of the addresses
 #       of your Clio servers, in order to bypass xrpld's rate limiting.
 #
-#       TLS/SSL can be enabled for gRPC by specifying ssl_cert and ssl_key.
-#       Both parameters must be provided together. The ssl_cert_chain parameter
-#       is optional and provides intermediate CA certificates for the certificate
-#       chain. The ssl_client_ca parameter is optional and enables mutual TLS
-#       (client certificate verification).
-#
 #   This port is commented out but can be enabled by removing
 #   the '#' from each corresponding line including the entry under [server]
 #
@@ -1471,74 +1465,11 @@ admin = 127.0.0.1
 protocol = ws
 send_queue_limit = 500
 
-# gRPC TLS/SSL Configuration
-#
-#   The gRPC port supports optional TLS/SSL encryption. When TLS is not
-#   configured, the gRPC server will accept unencrypted connections.
-#
-#   ssl_cert = <filename>
-#   ssl_key = <filename>
-#
-#       To enable TLS for gRPC, both ssl_cert and ssl_key must be specified.
-#       If only one is provided, xrpld will fail to start.
-#
-#       ssl_cert: Path to the server's SSL certificate file in PEM format.
-#       ssl_key:  Path to the server's SSL private key file in PEM format.
-#
-#       When configured, the gRPC server will only accept TLS-encrypted
-#       connections. Clients must use TLS (secure) channel credentials rather
-#       than plaintext / insecure connections.
-#
-#   ssl_cert_chain = <filename>
-#
-#       Optional. Path to intermediate CA certificate(s) in PEM format that
-#       complete the server's certificate chain.
-#
-#       This file should contain the intermediate CA certificate(s) needed
-#       to build a trust chain from the server certificate (ssl_cert) to a
-#       root CA that clients trust. Multiple certificates should be
-#       concatenated in PEM format.
-#
-#       This is needed when your server certificate was signed by an
-#       intermediate CA rather than directly by a root CA. Without this,
-#       clients may fail to verify your server certificate.
-#
-#       If not specified, only the server certificate from ssl_cert will be
-#       presented to clients.
-#
-#   ssl_client_ca = <filename>
-#
-#       Optional. Path to a CA certificate file in PEM format for verifying
-#       client certificates (mutual TLS / mTLS).
-#
-#       When specified, the gRPC server will verify client certificates
-#       against this CA. This enables mutual authentication where both the
-#       server and client verify each other's identity.
-#
-#       This is typically NOT needed for public-facing gRPC servers. Only
-#       use this if you want to restrict access to clients with valid
-#       certificates signed by the specified CA.
-#
-#       If not specified, the server will use one-way TLS (server
-#       authentication only) and will accept connections from any client.
-#
 [port_grpc]
 port = 50051
 ip = 127.0.0.1
 secure_gateway = 127.0.0.1
 
-# Optional TLS/SSL configuration for gRPC
-# To enable TLS, uncomment and configure both ssl_cert and ssl_key:
-#ssl_cert = /etc/ssl/certs/grpc-server.crt
-#ssl_key = /etc/ssl/private/grpc-server.key
-
-# Optional: Include intermediate CA certificates for complete certificate chain
-#ssl_cert_chain = /etc/ssl/certs/grpc-intermediate-ca.crt
-
-# Optional: Enable mutual TLS (client certificate verification)
-# Uncomment to require and verify client certificates:
-#ssl_client_ca = /etc/ssl/certs/grpc-client-ca.crt
-
 #[port_ws_public]
 #port = 6005
 #ip = 127.0.0.1

include/xrpl/basics/BasicConfig.h

@@ -33,7 +33,7 @@ private:
 
 public:
     /** Create an empty section. */
-    explicit Section(std::string name = "");
+    explicit Section(std::string const& name = "");
 
     /** Returns the name of this section. */
     std::string const&
@@ -275,7 +275,8 @@ public:
     bool
     had_trailing_comments() const
     {
-        return std::ranges::any_of(map_, [](auto s) { return s.second.had_trailing_comments(); });
+        return std::any_of(
+            map_.cbegin(), map_.cend(), [](auto s) { return s.second.had_trailing_comments(); });
     }
 
 protected:

include/xrpl/basics/CanProcess.h

@@ -1,134 +0,0 @@
-//------------------------------------------------------------------------------
-/*
-    This file is part of rippled: https://github.com/ripple/rippled
-    Copyright (c) 2024 Ripple Labs Inc.
-
-    Permission to use, copy, modify, and/or distribute this software for any
-    purpose  with  or without fee is hereby granted, provided that the above
-    copyright notice and this permission notice appear in all copies.
-
-    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
-    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
-    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
-    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
-    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
-    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-*/
-//==============================================================================
-
-#ifndef RIPPLE_BASICS_CANPROCESS_H_INCLUDED
-#define RIPPLE_BASICS_CANPROCESS_H_INCLUDED
-
-#include <functional>
-#include <mutex>
-#include <set>
-
-/** RAII class to check if an Item is already being processed on another thread,
- * as indicated by it's presence in a Collection.
- *
- * If the Item is not in the Collection, it will be added under lock in the
- * ctor, and removed under lock in the dtor. The object will be considered
- * "usable" and evaluate to `true`.
- *
- * If the Item is in the Collection, no changes will be made to the collection,
- * and the CanProcess object will be considered "unusable".
- *
- * It's up to the caller to decide what "usable" and "unusable" mean. (e.g.
- * Process or skip a block of code, or set a flag.)
- *
- * The current use is to avoid lock contention that would be involved in
- * processing something associated with the Item.
- *
- * Examples:
- *
- * void IncomingLedgers::acquireAsync(LedgerHash const& hash, ...)
- * {
- *    if (CanProcess check{acquiresMutex_, pendingAcquires_, hash})
- *    {
- *      acquire(hash, ...);
- *    }
- * }
- *
- * bool
- * NetworkOPsImp::recvValidation(
- *   std::shared_ptr<STValidation> const& val,
- *   std::string const& source)
- *   {
- *       CanProcess check(
- *           validationsMutex_, pendingValidations_, val->getLedgerHash());
- *       BypassAccept bypassAccept =
- *           check ? BypassAccept::no : BypassAccept::yes;
- *       handleNewValidation(app_, val, source, bypassAccept, m_journal);
- *   }
- *
- */
-class CanProcess
-{
-public:
-    template <class Mutex, class Collection, class Item>
-    CanProcess(Mutex& mtx, Collection& collection, Item const& item)
-        : cleanup_(insert(mtx, collection, item))
-    {
-    }
-
-    ~CanProcess()
-    {
-        if (cleanup_)
-            cleanup_();
-    }
-
-    explicit
-    operator bool() const
-    {
-        return static_cast<bool>(cleanup_);
-    }
-
-private:
-    template <bool useIterator, class Mutex, class Collection, class Item>
-    std::function<void()>
-    doInsert(Mutex& mtx, Collection& collection, Item const& item)
-    {
-        std::unique_lock<Mutex> lock(mtx);
-        // TODO: Use structured binding once LLVM 16 is the minimum supported
-        // version. See also: https://github.com/llvm/llvm-project/issues/48582
-        // https://github.com/llvm/llvm-project/commit/127bf44385424891eb04cff8e52d3f157fc2cb7c
-        auto const insertResult = collection.insert(item);
-        auto const it = insertResult.first;
-        if (!insertResult.second)
-            return {};
-        if constexpr (useIterator)
-            return [&, it]() {
-                std::unique_lock<Mutex> lock(mtx);
-                collection.erase(it);
-            };
-        else
-            return [&]() {
-                std::unique_lock<Mutex> lock(mtx);
-                collection.erase(item);
-            };
-    }
-
-    // Generic insert() function doesn't use iterators because they may get
-    // invalidated
-    template <class Mutex, class Collection, class Item>
-    std::function<void()>
-    insert(Mutex& mtx, Collection& collection, Item const& item)
-    {
-        return doInsert<false>(mtx, collection, item);
-    }
-
-    // Specialize insert() for std::set, which does not invalidate iterators for
-    // insert and erase
-    template <class Mutex, class Item>
-    std::function<void()>
-    insert(Mutex& mtx, std::set<Item>& collection, Item const& item)
-    {
-        return doInsert<true>(mtx, collection, item);
-    }
-
-    // If set, then the item is "usable"
-    std::function<void()> cleanup_;
-};
-
-#endif

include/xrpl/basics/CompressionAlgorithms.h

@@ -9,7 +9,9 @@
 #include <stdexcept>
 #include <vector>
 
-namespace xrpl::compression_algorithms {
+namespace xrpl {
+
+namespace compression_algorithms {
 
 /** LZ4 block compression.
  * @tparam BufferFactory Callable object or lambda.
@@ -139,4 +141,6 @@ lz4Decompress(
     return lz4Decompress(chunk, inSize, decompressed, decompressedSize);
 }
 
-}  // namespace xrpl::compression_algorithms
+}  // namespace compression_algorithms
+
+}  // namespace xrpl

include/xrpl/basics/Expected.h

@@ -61,7 +61,7 @@ template <class E>
 class Unexpected
 {
 public:
-    static_assert(!std::is_same_v<E, void>, "E must not be void");
+    static_assert(!std::is_same<E, void>::value, "E must not be void");
 
     Unexpected() = delete;
 

include/xrpl/basics/LocalValue.h

@@ -4,7 +4,6 @@
 
 #include <memory>
 #include <unordered_map>
-#include <utility>
 
 namespace xrpl {
 
@@ -29,7 +28,7 @@ struct LocalValues
         T t_;
 
         Value() = default;
-        explicit Value(T t) : t_(std::move(t))
+        explicit Value(T const& t) : t_(t)
         {
         }
 

include/xrpl/basics/Log.h

@@ -38,7 +38,7 @@ private:
         std::string partition_;
 
     public:
-        Sink(std::string partition, beast::severities::Severity thresh, Logs& logs);
+        Sink(std::string const& partition, beast::severities::Severity thresh, Logs& logs);
 
         Sink(Sink const&) = delete;
         Sink&

include/xrpl/basics/SlabAllocator.h

@@ -66,10 +66,12 @@ class SlabAllocator
             }
         }
 
-        // Calling this destructor will release the allocated memory but
-        // will not properly destroy any objects that are constructed in
-        // the block itself.
-        ~SlabBlock() = default;
+        ~SlabBlock()
+        {
+            // Calling this destructor will release the allocated memory but
+            // will not properly destroy any objects that are constructed in
+            // the block itself.
+        }
 
         SlabBlock(SlabBlock const& other) = delete;
         SlabBlock&
@@ -174,10 +176,12 @@ public:
     SlabAllocator&
     operator=(SlabAllocator&& other) = delete;
 
-    // FIXME: We can't destroy the memory blocks we've allocated, because
-    //        we can't be sure that they are not being used. Cleaning the
-    //        shutdown process up could make this possible.
-    ~SlabAllocator() = default;
+    ~SlabAllocator()
+    {
+        // FIXME: We can't destroy the memory blocks we've allocated, because
+        //        we can't be sure that they are not being used. Cleaning the
+        //        shutdown process up could make this possible.
+    }
 
     /** Returns the size of the memory block this allocator returns. */
     constexpr std::size_t
@@ -343,7 +347,9 @@ public:
     SlabAllocatorSet&
     operator=(SlabAllocatorSet&& other) = delete;
 
-    ~SlabAllocatorSet() = default;
+    ~SlabAllocatorSet()
+    {
+    }
 
     /** Returns a suitably aligned pointer, if one is available.
 

include/xrpl/basics/Slice.h

@@ -211,14 +211,14 @@ 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>
+std::enable_if_t<std::is_same<T, char>::value || std::is_same<T, unsigned char>::value, Slice>
 makeSlice(std::array<T, N> const& a)
 {
     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>
+std::enable_if_t<std::is_same<T, char>::value || std::is_same<T, unsigned char>::value, Slice>
 makeSlice(std::vector<T, Alloc> const& v)
 {
     return Slice(v.data(), v.size());

include/xrpl/basics/TaggedCache.h

@@ -251,7 +251,7 @@ private:
         }
     };
 
-    using Entry = std::conditional_t<IsKeyCache, KeyOnlyEntry, ValueEntry>;
+    typedef typename std::conditional<IsKeyCache, KeyOnlyEntry, ValueEntry>::type Entry;
 
     using KeyOnlyCacheType = hardened_partitioned_hash_map<key_type, KeyOnlyEntry, Hash, KeyEqual>;
 

include/xrpl/basics/ToString.h

@@ -12,7 +12,7 @@ namespace xrpl {
  */
 
 template <class T>
-std::enable_if_t<std::is_arithmetic_v<T>, std::string>
+typename std::enable_if<std::is_arithmetic<T>::value, std::string>::type
 to_string(T t)
 {
     return std::to_string(t);

include/xrpl/basics/base_uint.h

@@ -269,7 +269,7 @@ public:
         class Container,
         class = std::enable_if_t<
             detail::is_contiguous_container<Container>::value &&
-            std::is_trivially_copyable_v<typename Container::value_type>>>
+            std::is_trivially_copyable<typename Container::value_type>::value>>
     explicit base_uint(Container const& c)
     {
         XRPL_ASSERT(
@@ -281,7 +281,7 @@ public:
     template <class Container>
     std::enable_if_t<
         detail::is_contiguous_container<Container>::value &&
-            std::is_trivially_copyable_v<typename Container::value_type>,
+            std::is_trivially_copyable<typename Container::value_type>::value,
         base_uint&>
     operator=(Container const& c)
     {

include/xrpl/basics/contract.h

@@ -49,7 +49,8 @@ template <class E, class... Args>
 Throw(Args&&... args)
 {
     static_assert(
-        std::is_convertible_v<E*, std::exception*>, "Exception must derive from std::exception.");
+        std::is_convertible<E*, std::exception*>::value,
+        "Exception must derive from std::exception.");
 
     E e(std::forward<Args>(args)...);
     LogThrow(std::string("Throwing exception of type " + beast::type_name<E>() + ": ") + e.what());

include/xrpl/basics/random.h

@@ -15,8 +15,8 @@ namespace xrpl {
 #ifndef __INTELLISENSE__
 static_assert(
     // NOLINTNEXTLINE(misc-redundant-expression)
-    std::is_integral_v<beast::xor_shift_engine::result_type> &&
-        std::is_unsigned_v<beast::xor_shift_engine::result_type>,
+    std::is_integral<beast::xor_shift_engine::result_type>::value &&
+        std::is_unsigned<beast::xor_shift_engine::result_type>::value,
     "The XRPL default PRNG engine must return an unsigned integral type.");
 
 static_assert(
@@ -91,7 +91,7 @@ default_prng()
 */
 /** @{ */
 template <class Engine, class Integral>
-std::enable_if_t<std::is_integral_v<Integral> && detail::is_engine<Engine>::value, Integral>
+std::enable_if_t<std::is_integral<Integral>::value && detail::is_engine<Engine>::value, Integral>
 rand_int(Engine& engine, Integral min, Integral max)
 {
     XRPL_ASSERT(max > min, "xrpl::rand_int : max over min inputs");
@@ -103,35 +103,35 @@ rand_int(Engine& engine, Integral min, Integral max)
 }
 
 template <class Integral>
-std::enable_if_t<std::is_integral_v<Integral>, Integral>
+std::enable_if_t<std::is_integral<Integral>::value, Integral>
 rand_int(Integral min, Integral max)
 {
     return rand_int(default_prng(), min, max);
 }
 
 template <class Engine, class Integral>
-std::enable_if_t<std::is_integral_v<Integral> && detail::is_engine<Engine>::value, Integral>
+std::enable_if_t<std::is_integral<Integral>::value && detail::is_engine<Engine>::value, Integral>
 rand_int(Engine& engine, Integral max)
 {
     return rand_int(engine, Integral(0), max);
 }
 
 template <class Integral>
-std::enable_if_t<std::is_integral_v<Integral>, Integral>
+std::enable_if_t<std::is_integral<Integral>::value, Integral>
 rand_int(Integral max)
 {
     return rand_int(default_prng(), max);
 }
 
 template <class Integral, class Engine>
-std::enable_if_t<std::is_integral_v<Integral> && detail::is_engine<Engine>::value, Integral>
+std::enable_if_t<std::is_integral<Integral>::value && detail::is_engine<Engine>::value, Integral>
 rand_int(Engine& engine)
 {
     return rand_int(engine, std::numeric_limits<Integral>::max());
 }
 
 template <class Integral = int>
-std::enable_if_t<std::is_integral_v<Integral>, Integral>
+std::enable_if_t<std::is_integral<Integral>::value, Integral>
 rand_int()
 {
     return rand_int(default_prng(), std::numeric_limits<Integral>::max());
@@ -142,7 +142,7 @@ rand_int()
 /** @{ */
 template <class Byte, class Engine>
 std::enable_if_t<
-    (std::is_same_v<Byte, unsigned char> || std::is_same_v<Byte, std::uint8_t>) &&
+    (std::is_same<Byte, unsigned char>::value || std::is_same<Byte, std::uint8_t>::value) &&
         detail::is_engine<Engine>::value,
     Byte>
 rand_byte(Engine& engine)
@@ -152,7 +152,9 @@ rand_byte(Engine& engine)
 }
 
 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>
+std::enable_if_t<
+    (std::is_same<Byte, unsigned char>::value || std::is_same<Byte, std::uint8_t>::value),
+    Byte>
 rand_byte()
 {
     return rand_byte<Byte>(default_prng());

include/xrpl/basics/safe_cast.h

@@ -12,9 +12,9 @@ namespace xrpl {
 
 template <class Src, class Dest>
 concept SafeToCast = (std::is_integral_v<Src> && std::is_integral_v<Dest>) &&
-    (std::is_signed_v<Src> || std::is_unsigned_v<Dest>) &&
-    (std::is_signed_v<Src> != std::is_signed_v<Dest> ? sizeof(Dest) > sizeof(Src)
-                                                     : sizeof(Dest) >= sizeof(Src));
+    (std::is_signed<Src>::value || std::is_unsigned<Dest>::value) &&
+    (std::is_signed<Src>::value != std::is_signed<Dest>::value ? sizeof(Dest) > sizeof(Src)
+                                                               : 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>

include/xrpl/basics/strHex.h

@@ -10,9 +10,9 @@ std::string
 strHex(FwdIt begin, FwdIt end)
 {
     static_assert(
-        std::is_convertible_v<
+        std::is_convertible<
             typename std::iterator_traits<FwdIt>::iterator_category,
-            std::forward_iterator_tag>,
+            std::forward_iterator_tag>::value,
         "FwdIt must be a forward iterator");
     std::string result;
     result.reserve(2 * std::distance(begin, end));

include/xrpl/basics/tagged_integer.h

@@ -44,7 +44,8 @@ public:
 
     template <
         class OtherInt,
-        class = std::enable_if_t<std::is_integral_v<OtherInt> && sizeof(OtherInt) <= sizeof(Int)>>
+        class = typename std::enable_if<
+            std::is_integral<OtherInt>::value && sizeof(OtherInt) <= sizeof(Int)>::type>
     explicit constexpr tagged_integer(OtherInt value) noexcept : m_value(value)
     {
         static_assert(sizeof(tagged_integer) == sizeof(Int), "tagged_integer is adding padding");

include/xrpl/beast/container/aged_container_utility.h

@@ -9,7 +9,7 @@ namespace beast {
 
 /** Expire aged container items past the specified age. */
 template <class AgedContainer, class Rep, class Period>
-std::enable_if_t<is_aged_container<AgedContainer>::value, std::size_t>
+typename std::enable_if<is_aged_container<AgedContainer>::value, std::size_t>::type
 expire(AgedContainer& c, std::chrono::duration<Rep, Period> const& age)
 {
     std::size_t n(0);

include/xrpl/beast/container/detail/aged_associative_container.h

@@ -1,6 +1,7 @@
 #pragma once
 
-namespace beast::detail {
+namespace beast {
+namespace detail {
 
 // Extracts the key portion of value
 template <bool maybe_map>
@@ -29,4 +30,5 @@ struct aged_associative_container_extract_t<false>
     }
 };
 
-}  // namespace beast::detail
+}  // namespace detail
+}  // namespace beast

include/xrpl/beast/container/detail/aged_container_iterator.h

@@ -2,7 +2,6 @@
 
 #include <iterator>
 #include <type_traits>
-#include <utility>
 
 namespace beast {
 
@@ -132,7 +131,7 @@ private:
     friend class aged_container_iterator;
 
     template <class OtherIterator>
-    aged_container_iterator(OtherIterator iter) : m_iter(std::move(iter))
+    aged_container_iterator(OtherIterator const& iter) : m_iter(iter)
     {
     }
 

include/xrpl/beast/container/detail/aged_ordered_container.h

@@ -57,7 +57,8 @@ template <
     class T,
     class Clock = std::chrono::steady_clock,
     class Compare = std::less<Key>,
-    class Allocator = std::allocator<std::conditional_t<IsMap, std::pair<Key const, T>, Key>>>
+    class Allocator =
+        std::allocator<typename std::conditional<IsMap, std::pair<Key const, T>, Key>::type>>
 class aged_ordered_container
 {
 public:
@@ -66,7 +67,7 @@ public:
     using duration = typename clock_type::duration;
     using key_type = Key;
     using mapped_type = T;
-    using value_type = std::conditional_t<IsMap, std::pair<Key const, T>, Key>;
+    using value_type = typename std::conditional<IsMap, std::pair<Key const, T>, Key>::type;
     using size_type = std::size_t;
     using difference_type = std::ptrdiff_t;
 
@@ -109,7 +110,8 @@ private:
 
         template <
             class... Args,
-            class = std::enable_if_t<std::is_constructible_v<value_type, Args...>>>
+            class =
+                typename std::enable_if<std::is_constructible<value_type, Args...>::value>::type>
         element(time_point const& when_, Args&&... args)
             : value(std::forward<Args>(args)...), when(when_)
         {
@@ -133,7 +135,9 @@ private:
             return Compare::operator()(lhs.first, rhs.first);
         }
 
-        pair_value_compare() = default;
+        pair_value_compare()
+        {
+        }
 
         pair_value_compare(pair_value_compare const& other) : Compare(other)
         {
@@ -196,7 +200,7 @@ private:
     using list_type = typename boost::intrusive::
         make_list<element, boost::intrusive::constant_time_size<false>>::type;
 
-    using cont_type = std::conditional_t<
+    using cont_type = typename std::conditional<
         IsMulti,
         typename boost::intrusive::make_multiset<
             element,
@@ -205,7 +209,7 @@ private:
         typename boost::intrusive::make_set<
             element,
             boost::intrusive::constant_time_size<true>,
-            boost::intrusive::compare<KeyValueCompare>>::type>;
+            boost::intrusive::compare<KeyValueCompare>>::type>::type;
 
     using ElementAllocator =
         typename std::allocator_traits<Allocator>::template rebind_alloc<element>;
@@ -370,7 +374,7 @@ private:
 
 public:
     using key_compare = Compare;
-    using value_compare = std::conditional_t<IsMap, pair_value_compare, Compare>;
+    using value_compare = typename std::conditional<IsMap, pair_value_compare, Compare>::type;
     using allocator_type = Allocator;
     using reference = value_type&;
     using const_reference = value_type const&;
@@ -398,8 +402,6 @@ public:
 
     class chronological_t
     {
-        chronological_t() = default;
-
     public:
         // A set iterator (IsMap==false) is always const
         // because the elements of a set are immutable.
@@ -487,7 +489,7 @@ public:
         iterator
         iterator_to(value_type& value)
         {
-            static_assert(std::is_standard_layout_v<element>, "must be standard layout");
+            static_assert(std::is_standard_layout<element>::value, "must be standard layout");
             return list.iterator_to(*reinterpret_cast<element*>(
                 reinterpret_cast<uint8_t*>(&value) -
                 ((std::size_t)std::addressof(((element*)0)->member))));
@@ -496,16 +498,20 @@ public:
         const_iterator
         iterator_to(value_type const& value) const
         {
-            static_assert(std::is_standard_layout_v<element>, "must be standard layout");
+            static_assert(std::is_standard_layout<element>::value, "must be standard layout");
             return list.iterator_to(*reinterpret_cast<element const*>(
                 reinterpret_cast<uint8_t const*>(&value) -
                 ((std::size_t)std::addressof(((element*)0)->member))));
         }
 
+    private:
+        chronological_t()
+        {
+        }
+
         chronological_t(chronological_t const&) = delete;
         chronological_t(chronological_t&&) = delete;
 
-    private:
         friend class aged_ordered_container;
         list_type mutable list;
     } chronological;
@@ -611,30 +617,30 @@ public:
         class K,
         bool maybe_multi = IsMulti,
         bool maybe_map = IsMap,
-        class = std::enable_if_t<maybe_map && !maybe_multi>>
-    std::conditional_t<IsMap, T, void*>&
+        class = typename std::enable_if<maybe_map && !maybe_multi>::type>
+    typename std::conditional<IsMap, T, void*>::type&
     at(K const& k);
 
     template <
         class K,
         bool maybe_multi = IsMulti,
         bool maybe_map = IsMap,
-        class = std::enable_if_t<maybe_map && !maybe_multi>>
+        class = typename std::enable_if<maybe_map && !maybe_multi>::type>
     typename std::conditional<IsMap, T, void*>::type const&
     at(K const& k) const;
 
     template <
         bool maybe_multi = IsMulti,
         bool maybe_map = IsMap,
-        class = std::enable_if_t<maybe_map && !maybe_multi>>
-    std::conditional_t<IsMap, T, void*>&
+        class = typename std::enable_if<maybe_map && !maybe_multi>::type>
+    typename std::conditional<IsMap, T, void*>::type&
     operator[](Key const& key);
 
     template <
         bool maybe_multi = IsMulti,
         bool maybe_map = IsMap,
-        class = std::enable_if_t<maybe_map && !maybe_multi>>
-    std::conditional_t<IsMap, T, void*>&
+        class = typename std::enable_if<maybe_map && !maybe_multi>::type>
+    typename std::conditional<IsMap, T, void*>::type&
     operator[](Key&& key);
 
     //--------------------------------------------------------------------------
@@ -718,7 +724,7 @@ public:
     iterator
     iterator_to(value_type& value)
     {
-        static_assert(std::is_standard_layout_v<element>, "must be standard layout");
+        static_assert(std::is_standard_layout<element>::value, "must be standard layout");
         return m_cont.iterator_to(*reinterpret_cast<element*>(
             reinterpret_cast<uint8_t*>(&value) -
             ((std::size_t)std::addressof(((element*)0)->member))));
@@ -727,7 +733,7 @@ public:
     const_iterator
     iterator_to(value_type const& value) const
     {
-        static_assert(std::is_standard_layout_v<element>, "must be standard layout");
+        static_assert(std::is_standard_layout<element>::value, "must be standard layout");
         return m_cont.iterator_to(*reinterpret_cast<element const*>(
             reinterpret_cast<uint8_t const*>(&value) -
             ((std::size_t)std::addressof(((element*)0)->member))));
@@ -769,35 +775,37 @@ public:
     // map, set
     template <bool maybe_multi = IsMulti>
     auto
-    insert(value_type const& value) -> std::enable_if_t<!maybe_multi, std::pair<iterator, bool>>;
+    insert(value_type const& value) ->
+        typename std::enable_if<!maybe_multi, std::pair<iterator, bool>>::type;
 
     // multimap, multiset
     template <bool maybe_multi = IsMulti>
     auto
-    insert(value_type const& value) -> std::enable_if_t<maybe_multi, iterator>;
+    insert(value_type const& value) -> typename std::enable_if<maybe_multi, iterator>::type;
 
     // set
     template <bool maybe_multi = IsMulti, bool maybe_map = IsMap>
     auto
-    insert(value_type&& value)
-        -> std::enable_if_t<!maybe_multi && !maybe_map, std::pair<iterator, bool>>;
+    insert(value_type&& value) ->
+        typename std::enable_if<!maybe_multi && !maybe_map, std::pair<iterator, bool>>::type;
 
     // multiset
     template <bool maybe_multi = IsMulti, bool maybe_map = IsMap>
     auto
-    insert(value_type&& value) -> std::enable_if_t<maybe_multi && !maybe_map, iterator>;
+    insert(value_type&& value) ->
+        typename std::enable_if<maybe_multi && !maybe_map, iterator>::type;
 
     //---
 
     // map, set
     template <bool maybe_multi = IsMulti>
     auto
-    insert(const_iterator hint, value_type const& value)
-        -> std::enable_if_t<!maybe_multi, iterator>;
+    insert(const_iterator hint, value_type const& value) ->
+        typename std::enable_if<!maybe_multi, iterator>::type;
 
     // multimap, multiset
     template <bool maybe_multi = IsMulti>
-    std::enable_if_t<maybe_multi, iterator>
+    typename std::enable_if<maybe_multi, iterator>::type
     insert(const_iterator /*hint*/, value_type const& value)
     {
         // VFALCO TODO Figure out how to utilize 'hint'
@@ -807,11 +815,12 @@ public:
     // map, set
     template <bool maybe_multi = IsMulti>
     auto
-    insert(const_iterator hint, value_type&& value) -> std::enable_if_t<!maybe_multi, iterator>;
+    insert(const_iterator hint, value_type&& value) ->
+        typename std::enable_if<!maybe_multi, iterator>::type;
 
     // multimap, multiset
     template <bool maybe_multi = IsMulti>
-    std::enable_if_t<maybe_multi, iterator>
+    typename std::enable_if<maybe_multi, iterator>::type
     insert(const_iterator /*hint*/, value_type&& value)
     {
         // VFALCO TODO Figure out how to utilize 'hint'
@@ -820,9 +829,9 @@ public:
 
     // map, multimap
     template <class P, bool maybe_map = IsMap>
-    std::enable_if_t<
-        maybe_map && std::is_constructible_v<value_type, P&&>,
-        std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>>
+    typename std::enable_if<
+        maybe_map && std::is_constructible<value_type, P&&>::value,
+        typename std::conditional<IsMulti, iterator, std::pair<iterator, bool>>::type>::type
     insert(P&& value)
     {
         return emplace(std::forward<P>(value));
@@ -830,9 +839,9 @@ public:
 
     // map, multimap
     template <class P, bool maybe_map = IsMap>
-    std::enable_if_t<
-        maybe_map && std::is_constructible_v<value_type, P&&>,
-        std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>>
+    typename std::enable_if<
+        maybe_map && std::is_constructible<value_type, P&&>::value,
+        typename std::conditional<IsMulti, iterator, std::pair<iterator, bool>>::type>::type
     insert(const_iterator hint, P&& value)
     {
         return emplace_hint(hint, std::forward<P>(value));
@@ -855,22 +864,23 @@ public:
     // map, set
     template <bool maybe_multi = IsMulti, class... Args>
     auto
-    emplace(Args&&... args) -> std::enable_if_t<!maybe_multi, std::pair<iterator, bool>>;
+    emplace(Args&&... args) ->
+        typename std::enable_if<!maybe_multi, std::pair<iterator, bool>>::type;
 
     // multiset, multimap
     template <bool maybe_multi = IsMulti, class... Args>
     auto
-    emplace(Args&&... args) -> std::enable_if_t<maybe_multi, iterator>;
+    emplace(Args&&... args) -> typename std::enable_if<maybe_multi, iterator>::type;
 
     // map, set
     template <bool maybe_multi = IsMulti, class... Args>
     auto
-    emplace_hint(const_iterator hint, Args&&... args)
-        -> std::enable_if_t<!maybe_multi, std::pair<iterator, bool>>;
+    emplace_hint(const_iterator hint, Args&&... args) ->
+        typename std::enable_if<!maybe_multi, std::pair<iterator, bool>>::type;
 
     // multiset, multimap
     template <bool maybe_multi = IsMulti, class... Args>
-    std::enable_if_t<maybe_multi, iterator>
+    typename std::enable_if<maybe_multi, iterator>::type
     emplace_hint(const_iterator /*hint*/, Args&&... args)
     {
         // VFALCO TODO Figure out how to utilize 'hint'
@@ -1154,12 +1164,12 @@ private:
 
     template <
         bool maybe_propagate = std::allocator_traits<Allocator>::propagate_on_container_swap::value>
-    std::enable_if_t<maybe_propagate>
+    typename std::enable_if<maybe_propagate>::type
     swap_data(aged_ordered_container& other) noexcept;
 
     template <
         bool maybe_propagate = std::allocator_traits<Allocator>::propagate_on_container_swap::value>
-    std::enable_if_t<!maybe_propagate>
+    typename std::enable_if<!maybe_propagate>::type
     swap_data(aged_ordered_container& other) noexcept;
 
 private:
@@ -1386,7 +1396,7 @@ aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::opera
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
 template <class K, bool maybe_multi, bool maybe_map, class>
-std::conditional_t<IsMap, T, void*>&
+typename std::conditional<IsMap, T, void*>::type&
 aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::at(K const& k)
 {
     auto const iter(m_cont.find(k, std::cref(m_config.key_compare())));
@@ -1408,7 +1418,7 @@ aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::at(K
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
 template <bool maybe_multi, bool maybe_map, class>
-std::conditional_t<IsMap, T, void*>&
+typename std::conditional<IsMap, T, void*>::type&
 aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::operator[](
     Key const& key)
 {
@@ -1427,7 +1437,7 @@ aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::opera
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
 template <bool maybe_multi, bool maybe_map, class>
-std::conditional_t<IsMap, T, void*>&
+typename std::conditional<IsMap, T, void*>::type&
 aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::operator[](Key&& key)
 {
     typename cont_type::insert_commit_data d;
@@ -1462,7 +1472,8 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool maybe_multi>
 auto
 aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(
-    value_type const& value) -> std::enable_if_t<!maybe_multi, std::pair<iterator, bool>>
+    value_type const& value) ->
+    typename std::enable_if<!maybe_multi, std::pair<iterator, bool>>::type
 {
     typename cont_type::insert_commit_data d;
     auto const result(m_cont.insert_check(extract(value), std::cref(m_config.key_compare()), d));
@@ -1481,7 +1492,7 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool maybe_multi>
 auto
 aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(
-    value_type const& value) -> std::enable_if_t<maybe_multi, iterator>
+    value_type const& value) -> typename std::enable_if<maybe_multi, iterator>::type
 {
     auto const before(m_cont.upper_bound(extract(value), std::cref(m_config.key_compare())));
     element* const p(new_element(value));
@@ -1495,7 +1506,8 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool maybe_multi, bool maybe_map>
 auto
 aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(
-    value_type&& value) -> std::enable_if_t<!maybe_multi && !maybe_map, std::pair<iterator, bool>>
+    value_type&& value) ->
+    typename std::enable_if<!maybe_multi && !maybe_map, std::pair<iterator, bool>>::type
 {
     typename cont_type::insert_commit_data d;
     auto const result(m_cont.insert_check(extract(value), std::cref(m_config.key_compare()), d));
@@ -1514,7 +1526,7 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool maybe_multi, bool maybe_map>
 auto
 aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(
-    value_type&& value) -> std::enable_if_t<maybe_multi && !maybe_map, iterator>
+    value_type&& value) -> typename std::enable_if<maybe_multi && !maybe_map, iterator>::type
 {
     auto const before(m_cont.upper_bound(extract(value), std::cref(m_config.key_compare())));
     element* const p(new_element(std::move(value)));
@@ -1531,7 +1543,7 @@ template <bool maybe_multi>
 auto
 aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(
     const_iterator hint,
-    value_type const& value) -> std::enable_if_t<!maybe_multi, iterator>
+    value_type const& value) -> typename std::enable_if<!maybe_multi, iterator>::type
 {
     typename cont_type::insert_commit_data d;
     auto const result(
@@ -1552,7 +1564,7 @@ template <bool maybe_multi>
 auto
 aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::insert(
     const_iterator hint,
-    value_type&& value) -> std::enable_if_t<!maybe_multi, iterator>
+    value_type&& value) -> typename std::enable_if<!maybe_multi, iterator>::type
 {
     typename cont_type::insert_commit_data d;
     auto const result(
@@ -1572,7 +1584,7 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool maybe_multi, class... Args>
 auto
 aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::emplace(Args&&... args)
-    -> std::enable_if_t<!maybe_multi, std::pair<iterator, bool>>
+    -> typename std::enable_if<!maybe_multi, std::pair<iterator, bool>>::type
 {
     // VFALCO NOTE Its unfortunate that we need to
     //             construct element here
@@ -1594,7 +1606,7 @@ template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compa
 template <bool maybe_multi, class... Args>
 auto
 aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::emplace(Args&&... args)
-    -> std::enable_if_t<maybe_multi, iterator>
+    -> typename std::enable_if<maybe_multi, iterator>::type
 {
     element* const p(new_element(std::forward<Args>(args)...));
     auto const before(m_cont.upper_bound(extract(p->value), std::cref(m_config.key_compare())));
@@ -1609,7 +1621,7 @@ template <bool maybe_multi, class... Args>
 auto
 aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::emplace_hint(
     const_iterator hint,
-    Args&&... args) -> std::enable_if_t<!maybe_multi, std::pair<iterator, bool>>
+    Args&&... args) -> typename std::enable_if<!maybe_multi, std::pair<iterator, bool>>::type
 {
     // VFALCO NOTE Its unfortunate that we need to
     //             construct element here
@@ -1759,7 +1771,7 @@ aged_ordered_container<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 maybe_propagate>
-std::enable_if_t<maybe_propagate>
+typename std::enable_if<maybe_propagate>::type
 aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::swap_data(
     aged_ordered_container& other) noexcept
 {
@@ -1770,7 +1782,7 @@ aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::swap_
 
 template <bool IsMulti, bool IsMap, class Key, class T, class Clock, class Compare, class Allocator>
 template <bool maybe_propagate>
-std::enable_if_t<!maybe_propagate>
+typename std::enable_if<!maybe_propagate>::type
 aged_ordered_container<IsMulti, IsMap, Key, T, Clock, Compare, Allocator>::swap_data(
     aged_ordered_container& other) noexcept
 {

include/xrpl/beast/container/detail/aged_unordered_container.h

@@ -62,7 +62,8 @@ template <
     class Clock = std::chrono::steady_clock,
     class Hash = std::hash<Key>,
     class KeyEqual = std::equal_to<Key>,
-    class Allocator = std::allocator<std::conditional_t<IsMap, std::pair<Key const, T>, Key>>>
+    class Allocator =
+        std::allocator<typename std::conditional<IsMap, std::pair<Key const, T>, Key>::type>>
 class aged_unordered_container
 {
 public:
@@ -71,7 +72,7 @@ public:
     using duration = typename clock_type::duration;
     using key_type = Key;
     using mapped_type = T;
-    using value_type = std::conditional_t<IsMap, std::pair<Key const, T>, Key>;
+    using value_type = typename std::conditional<IsMap, std::pair<Key const, T>, Key>::type;
     using size_type = std::size_t;
     using difference_type = std::ptrdiff_t;
 
@@ -114,7 +115,8 @@ private:
 
         template <
             class... Args,
-            class = std::enable_if_t<std::is_constructible_v<value_type, Args...>>>
+            class =
+                typename std::enable_if<std::is_constructible<value_type, Args...>::value>::type>
         element(time_point const& when_, Args&&... args)
             : value(std::forward<Args>(args)...), when(when_)
         {
@@ -131,7 +133,9 @@ private:
         using argument_type = element;
         using result_type = size_t;
 
-        ValueHash() = default;
+        ValueHash()
+        {
+        }
 
         ValueHash(Hash const& h) : Hash(h)
         {
@@ -165,7 +169,9 @@ private:
         using second_argument_type = element;
         using result_type = bool;
 
-        KeyValueEqual() = default;
+        KeyValueEqual()
+        {
+        }
 
         KeyValueEqual(KeyEqual const& keyEqual) : KeyEqual(keyEqual)
         {
@@ -205,7 +211,7 @@ private:
     using list_type = typename boost::intrusive::
         make_list<element, boost::intrusive::constant_time_size<false>>::type;
 
-    using cont_type = std::conditional_t<
+    using cont_type = typename std::conditional<
         IsMulti,
         typename boost::intrusive::make_unordered_multiset<
             element,
@@ -218,7 +224,7 @@ private:
             boost::intrusive::constant_time_size<true>,
             boost::intrusive::hash<ValueHash>,
             boost::intrusive::equal<KeyValueEqual>,
-            boost::intrusive::cache_begin<true>>::type>;
+            boost::intrusive::cache_begin<true>>::type>::type;
 
     using bucket_type = typename cont_type::bucket_type;
     using bucket_traits = typename cont_type::bucket_traits;
@@ -656,7 +662,7 @@ public:
         iterator
         iterator_to(value_type& value)
         {
-            static_assert(std::is_standard_layout_v<element>, "must be standard layout");
+            static_assert(std::is_standard_layout<element>::value, "must be standard layout");
             return list.iterator_to(*reinterpret_cast<element*>(
                 reinterpret_cast<uint8_t*>(&value) -
                 ((std::size_t)std::addressof(((element*)0)->member))));
@@ -665,17 +671,20 @@ public:
         const_iterator
         iterator_to(value_type const& value) const
         {
-            static_assert(std::is_standard_layout_v<element>, "must be standard layout");
+            static_assert(std::is_standard_layout<element>::value, "must be standard layout");
             return list.iterator_to(*reinterpret_cast<element const*>(
                 reinterpret_cast<uint8_t const*>(&value) -
                 ((std::size_t)std::addressof(((element*)0)->member))));
         }
 
+    private:
+        chronological_t()
+        {
+        }
+
         chronological_t(chronological_t const&) = delete;
         chronological_t(chronological_t&&) = delete;
-        chronological_t() = default;
 
-    private:
         friend class aged_unordered_container;
         list_type mutable list;
     } chronological;
@@ -853,30 +862,30 @@ public:
         class K,
         bool maybe_multi = IsMulti,
         bool maybe_map = IsMap,
-        class = std::enable_if_t<maybe_map && !maybe_multi>>
-    std::conditional_t<IsMap, T, void*>&
+        class = typename std::enable_if<maybe_map && !maybe_multi>::type>
+    typename std::conditional<IsMap, T, void*>::type&
     at(K const& k);
 
     template <
         class K,
         bool maybe_multi = IsMulti,
         bool maybe_map = IsMap,
-        class = std::enable_if_t<maybe_map && !maybe_multi>>
+        class = typename std::enable_if<maybe_map && !maybe_multi>::type>
     typename std::conditional<IsMap, T, void*>::type const&
     at(K const& k) const;
 
     template <
         bool maybe_multi = IsMulti,
         bool maybe_map = IsMap,
-        class = std::enable_if_t<maybe_map && !maybe_multi>>
-    std::conditional_t<IsMap, T, void*>&
+        class = typename std::enable_if<maybe_map && !maybe_multi>::type>
+    typename std::conditional<IsMap, T, void*>::type&
     operator[](Key const& key);
 
     template <
         bool maybe_multi = IsMulti,
         bool maybe_map = IsMap,
-        class = std::enable_if_t<maybe_map && !maybe_multi>>
-    std::conditional_t<IsMap, T, void*>&
+        class = typename std::enable_if<maybe_map && !maybe_multi>::type>
+    typename std::conditional<IsMap, T, void*>::type&
     operator[](Key&& key);
 
     //--------------------------------------------------------------------------
@@ -924,7 +933,7 @@ public:
     iterator
     iterator_to(value_type& value)
     {
-        static_assert(std::is_standard_layout_v<element>, "must be standard layout");
+        static_assert(std::is_standard_layout<element>::value, "must be standard layout");
         return m_cont.iterator_to(*reinterpret_cast<element*>(
             reinterpret_cast<uint8_t*>(&value) -
             ((std::size_t)std::addressof(((element*)0)->member))));
@@ -933,7 +942,7 @@ public:
     const_iterator
     iterator_to(value_type const& value) const
     {
-        static_assert(std::is_standard_layout_v<element>, "must be standard layout");
+        static_assert(std::is_standard_layout<element>::value, "must be standard layout");
         return m_cont.iterator_to(*reinterpret_cast<element const*>(
             reinterpret_cast<uint8_t const*>(&value) -
             ((std::size_t)std::addressof(((element*)0)->member))));
@@ -975,27 +984,29 @@ public:
     // map, set
     template <bool maybe_multi = IsMulti>
     auto
-    insert(value_type const& value) -> std::enable_if_t<!maybe_multi, std::pair<iterator, bool>>;
+    insert(value_type const& value) ->
+        typename std::enable_if<!maybe_multi, std::pair<iterator, bool>>::type;
 
     // multimap, multiset
     template <bool maybe_multi = IsMulti>
     auto
-    insert(value_type const& value) -> std::enable_if_t<maybe_multi, iterator>;
+    insert(value_type const& value) -> typename std::enable_if<maybe_multi, iterator>::type;
 
     // map, set
     template <bool maybe_multi = IsMulti, bool maybe_map = IsMap>
     auto
-    insert(value_type&& value)
-        -> std::enable_if_t<!maybe_multi && !maybe_map, std::pair<iterator, bool>>;
+    insert(value_type&& value) ->
+        typename std::enable_if<!maybe_multi && !maybe_map, std::pair<iterator, bool>>::type;
 
     // multimap, multiset
     template <bool maybe_multi = IsMulti, bool maybe_map = IsMap>
     auto
-    insert(value_type&& value) -> std::enable_if_t<maybe_multi && !maybe_map, iterator>;
+    insert(value_type&& value) ->
+        typename std::enable_if<maybe_multi && !maybe_map, iterator>::type;
 
     // map, set
     template <bool maybe_multi = IsMulti>
-    std::enable_if_t<!maybe_multi, iterator>
+    typename std::enable_if<!maybe_multi, iterator>::type
     insert(const_iterator /*hint*/, value_type const& value)
     {
         // Hint is ignored but we provide the interface so
@@ -1005,7 +1016,7 @@ public:
 
     // multimap, multiset
     template <bool maybe_multi = IsMulti>
-    std::enable_if_t<maybe_multi, iterator>
+    typename std::enable_if<maybe_multi, iterator>::type
     insert(const_iterator /*hint*/, value_type const& value)
     {
         // VFALCO TODO The hint could be used to let
@@ -1015,7 +1026,7 @@ public:
 
     // map, set
     template <bool maybe_multi = IsMulti>
-    std::enable_if_t<!maybe_multi, iterator>
+    typename std::enable_if<!maybe_multi, iterator>::type
     insert(const_iterator /*hint*/, value_type&& value)
     {
         // Hint is ignored but we provide the interface so
@@ -1025,7 +1036,7 @@ public:
 
     // multimap, multiset
     template <bool maybe_multi = IsMulti>
-    std::enable_if_t<maybe_multi, iterator>
+    typename std::enable_if<maybe_multi, iterator>::type
     insert(const_iterator /*hint*/, value_type&& value)
     {
         // VFALCO TODO The hint could be used to let
@@ -1035,9 +1046,9 @@ public:
 
     // map, multimap
     template <class P, bool maybe_map = IsMap>
-    std::enable_if_t<
-        maybe_map && std::is_constructible_v<value_type, P&&>,
-        std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>>
+    typename std::enable_if<
+        maybe_map && std::is_constructible<value_type, P&&>::value,
+        typename std::conditional<IsMulti, iterator, std::pair<iterator, bool>>::type>::type
     insert(P&& value)
     {
         return emplace(std::forward<P>(value));
@@ -1045,9 +1056,9 @@ public:
 
     // map, multimap
     template <class P, bool maybe_map = IsMap>
-    std::enable_if_t<
-        maybe_map && std::is_constructible_v<value_type, P&&>,
-        std::conditional_t<IsMulti, iterator, std::pair<iterator, bool>>>
+    typename std::enable_if<
+        maybe_map && std::is_constructible<value_type, P&&>::value,
+        typename std::conditional<IsMulti, iterator, std::pair<iterator, bool>>::type>::type
     insert(const_iterator hint, P&& value)
     {
         return emplace_hint(hint, std::forward<P>(value));
@@ -1069,22 +1080,23 @@ public:
     // set, map
     template <bool maybe_multi = IsMulti, class... Args>
     auto
-    emplace(Args&&... args) -> std::enable_if_t<!maybe_multi, std::pair<iterator, bool>>;
+    emplace(Args&&... args) ->
+        typename std::enable_if<!maybe_multi, std::pair<iterator, bool>>::type;
 
     // multiset, multimap
     template <bool maybe_multi = IsMulti, class... Args>
     auto
-    emplace(Args&&... args) -> std::enable_if_t<maybe_multi, iterator>;
+    emplace(Args&&... args) -> typename std::enable_if<maybe_multi, iterator>::type;
 
     // set, map
     template <bool maybe_multi = IsMulti, class... Args>
     auto
-    emplace_hint(const_iterator /*hint*/, Args&&... args)
-        -> std::enable_if_t<!maybe_multi, std::pair<iterator, bool>>;
+    emplace_hint(const_iterator /*hint*/, Args&&... args) ->
+        typename std::enable_if<!maybe_multi, std::pair<iterator, bool>>::type;
 
     // multiset, multimap
     template <bool maybe_multi = IsMulti, class... Args>
-    std::enable_if_t<maybe_multi, iterator>
+    typename std::enable_if<maybe_multi, iterator>::type
     emplace_hint(const_iterator /*hint*/, Args&&... args)
     {
         // VFALCO TODO The hint could be used for multi, to let
@@ -1316,7 +1328,7 @@ public:
         class OtherHash,
         class OtherAllocator,
         bool maybe_multi = IsMulti>
-    std::enable_if_t<!maybe_multi, bool>
+    typename std::enable_if<!maybe_multi, bool>::type
     operator==(aged_unordered_container<
                false,
                OtherIsMap,
@@ -1335,7 +1347,7 @@ public:
         class OtherHash,
         class OtherAllocator,
         bool maybe_multi = IsMulti>
-    std::enable_if_t<maybe_multi, bool>
+    typename std::enable_if<maybe_multi, bool>::type
     operator==(aged_unordered_container<
                true,
                OtherIsMap,
@@ -1389,13 +1401,14 @@ private:
     // map, set
     template <bool maybe_multi = IsMulti>
     auto
-    insert_unchecked(value_type const& value)
-        -> std::enable_if_t<!maybe_multi, std::pair<iterator, bool>>;
+    insert_unchecked(value_type const& value) ->
+        typename std::enable_if<!maybe_multi, std::pair<iterator, bool>>::type;
 
     // multimap, multiset
     template <bool maybe_multi = IsMulti>
     auto
-    insert_unchecked(value_type const& value) -> std::enable_if_t<maybe_multi, iterator>;
+    insert_unchecked(value_type const& value) ->
+        typename std::enable_if<maybe_multi, iterator>::type;
 
     template <class InputIt>
     void
@@ -1436,7 +1449,7 @@ private:
 
     template <
         bool maybe_propagate = std::allocator_traits<Allocator>::propagate_on_container_swap::value>
-    std::enable_if_t<maybe_propagate>
+    typename std::enable_if<maybe_propagate>::type
     swap_data(aged_unordered_container& other) noexcept
     {
         std::swap(m_config.key_compare(), other.m_config.key_compare());
@@ -1446,7 +1459,7 @@ private:
 
     template <
         bool maybe_propagate = std::allocator_traits<Allocator>::propagate_on_container_swap::value>
-    std::enable_if_t<!maybe_propagate>
+    typename std::enable_if<!maybe_propagate>::type
     swap_data(aged_unordered_container& other) noexcept
     {
         std::swap(m_config.key_compare(), other.m_config.key_compare());
@@ -2101,7 +2114,7 @@ template <
     class KeyEqual,
     class Allocator>
 template <class K, bool maybe_multi, bool maybe_map, class>
-std::conditional_t<IsMap, T, void*>&
+typename std::conditional<IsMap, T, void*>::type&
 aged_unordered_container<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::at(K const& k)
 {
     auto const iter(
@@ -2142,7 +2155,7 @@ template <
     class KeyEqual,
     class Allocator>
 template <bool maybe_multi, bool maybe_map, class>
-std::conditional_t<IsMap, T, void*>&
+typename std::conditional<IsMap, T, void*>::type&
 aged_unordered_container<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::operator[](
     Key const& key)
 {
@@ -2171,7 +2184,7 @@ template <
     class KeyEqual,
     class Allocator>
 template <bool maybe_multi, bool maybe_map, class>
-std::conditional_t<IsMap, T, void*>&
+typename std::conditional<IsMap, T, void*>::type&
 aged_unordered_container<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::operator[](
     Key&& key)
 {
@@ -2226,7 +2239,8 @@ template <
 template <bool maybe_multi>
 auto
 aged_unordered_container<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::insert(
-    value_type const& value) -> std::enable_if_t<!maybe_multi, std::pair<iterator, bool>>
+    value_type const& value) ->
+    typename std::enable_if<!maybe_multi, std::pair<iterator, bool>>::type
 {
     maybe_rehash(1);
     typename cont_type::insert_commit_data d;
@@ -2258,7 +2272,7 @@ template <
 template <bool maybe_multi>
 auto
 aged_unordered_container<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::insert(
-    value_type const& value) -> std::enable_if_t<maybe_multi, iterator>
+    value_type const& value) -> typename std::enable_if<maybe_multi, iterator>::type
 {
     maybe_rehash(1);
     element* const p(new_element(value));
@@ -2280,7 +2294,8 @@ template <
 template <bool maybe_multi, bool maybe_map>
 auto
 aged_unordered_container<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::insert(
-    value_type&& value) -> std::enable_if_t<!maybe_multi && !maybe_map, std::pair<iterator, bool>>
+    value_type&& value) ->
+    typename std::enable_if<!maybe_multi && !maybe_map, std::pair<iterator, bool>>::type
 {
     maybe_rehash(1);
     typename cont_type::insert_commit_data d;
@@ -2312,7 +2327,7 @@ template <
 template <bool maybe_multi, bool maybe_map>
 auto
 aged_unordered_container<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::insert(
-    value_type&& value) -> std::enable_if_t<maybe_multi && !maybe_map, iterator>
+    value_type&& value) -> typename std::enable_if<maybe_multi && !maybe_map, iterator>::type
 {
     maybe_rehash(1);
     element* const p(new_element(std::move(value)));
@@ -2335,7 +2350,7 @@ template <
 template <bool maybe_multi, class... Args>
 auto
 aged_unordered_container<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::emplace(
-    Args&&... args) -> std::enable_if_t<!maybe_multi, std::pair<iterator, bool>>
+    Args&&... args) -> typename std::enable_if<!maybe_multi, std::pair<iterator, bool>>::type
 {
     maybe_rehash(1);
     // VFALCO NOTE Its unfortunate that we need to
@@ -2400,7 +2415,7 @@ template <
 template <bool maybe_multi, class... Args>
 auto
 aged_unordered_container<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::emplace(
-    Args&&... args) -> std::enable_if_t<maybe_multi, iterator>
+    Args&&... args) -> typename std::enable_if<maybe_multi, iterator>::type
 {
     maybe_rehash(1);
     element* const p(new_element(std::forward<Args>(args)...));
@@ -2423,7 +2438,7 @@ template <bool maybe_multi, class... Args>
 auto
 aged_unordered_container<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::emplace_hint(
     const_iterator /*hint*/,
-    Args&&... args) -> std::enable_if_t<!maybe_multi, std::pair<iterator, bool>>
+    Args&&... args) -> typename std::enable_if<!maybe_multi, std::pair<iterator, bool>>::type
 {
     maybe_rehash(1);
     // VFALCO NOTE Its unfortunate that we need to
@@ -2575,7 +2590,7 @@ template <
     class OtherHash,
     class OtherAllocator,
     bool maybe_multi>
-std::enable_if_t<!maybe_multi, bool>
+typename std::enable_if<!maybe_multi, bool>::type
 aged_unordered_container<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::operator==(
     aged_unordered_container<
         false,
@@ -2615,7 +2630,7 @@ template <
     class OtherHash,
     class OtherAllocator,
     bool maybe_multi>
-std::enable_if_t<maybe_multi, bool>
+typename std::enable_if<maybe_multi, bool>::type
 aged_unordered_container<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::operator==(
     aged_unordered_container<
         true,
@@ -2662,8 +2677,8 @@ template <
 template <bool maybe_multi>
 auto
 aged_unordered_container<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::
-    insert_unchecked(value_type const& value)
-        -> std::enable_if_t<!maybe_multi, std::pair<iterator, bool>>
+    insert_unchecked(value_type const& value) ->
+    typename std::enable_if<!maybe_multi, std::pair<iterator, bool>>::type
 {
     typename cont_type::insert_commit_data d;
     auto const result(m_cont.insert_check(
@@ -2694,7 +2709,8 @@ template <
 template <bool maybe_multi>
 auto
 aged_unordered_container<IsMulti, IsMap, Key, T, Clock, Hash, KeyEqual, Allocator>::
-    insert_unchecked(value_type const& value) -> std::enable_if_t<maybe_multi, iterator>
+    insert_unchecked(value_type const& value) ->
+    typename std::enable_if<maybe_multi, iterator>::type
 {
     element* const p(new_element(value));
     chronological.list.push_back(*p);

include/xrpl/beast/container/detail/empty_base_optimization.h

@@ -11,11 +11,12 @@
 #include <type_traits>
 #include <utility>
 
-namespace beast::detail {
+namespace beast {
+namespace detail {
 
 template <class T>
 struct is_empty_base_optimization_derived
-    : std::integral_constant<bool, std::is_empty_v<T> && !boost::is_final<T>::value>
+    : std::integral_constant<bool, std::is_empty<T>::value && !boost::is_final<T>::value>
 {
 };
 
@@ -85,4 +86,5 @@ public:
     }
 };
 
-}  // namespace beast::detail
+}  // namespace detail
+}  // namespace beast

include/xrpl/beast/core/List.h

@@ -16,7 +16,7 @@ struct CopyConst
 {
     explicit CopyConst() = default;
 
-    using type = std::remove_const_t<U>;
+    using type = typename std::remove_const<U>::type;
 };
 
 template <typename T, typename U>

include/xrpl/beast/core/LockFreeStack.h

@@ -13,16 +13,18 @@ class LockFreeStackIterator
 {
 protected:
     using Node = typename Container::Node;
-    using NodePtr = std::conditional_t<IsConst, Node const*, Node*>;
+    using NodePtr = typename std::conditional<IsConst, Node const*, Node*>::type;
 
 public:
     using iterator_category = std::forward_iterator_tag;
     using value_type = typename Container::value_type;
     using difference_type = typename Container::difference_type;
-    using pointer =
-        std::conditional_t<IsConst, typename Container::const_pointer, typename Container::pointer>;
-    using reference = std::
-        conditional_t<IsConst, typename Container::const_reference, typename Container::reference>;
+    using pointer = typename std::
+        conditional<IsConst, typename Container::const_pointer, typename Container::pointer>::type;
+    using reference = typename std::conditional<
+        IsConst,
+        typename Container::const_reference,
+        typename Container::reference>::type;
 
     LockFreeStackIterator() : m_node()
     {

include/xrpl/beast/hash/hash_append.h

@@ -69,7 +69,7 @@ template <class T>
 struct is_uniquely_represented
     : public std::integral_constant<
           bool,
-          std::is_integral_v<T> || std::is_enum_v<T> || std::is_pointer_v<T>>
+          std::is_integral<T>::value || std::is_enum<T>::value || std::is_pointer<T>::value>
 {
     explicit is_uniquely_represented() = default;
 };
@@ -210,7 +210,7 @@ hash_append(Hasher& h, T const& t) noexcept
 template <class Hasher, class T>
 inline std::enable_if_t<
     !is_contiguously_hashable<T, Hasher>::value &&
-    (std::is_integral_v<T> || std::is_pointer_v<T> || std::is_enum_v<T>)>
+    (std::is_integral<T>::value || std::is_pointer<T>::value || std::is_enum<T>::value)>
 hash_append(Hasher& h, T t) noexcept
 {
     detail::reverse_bytes(t);
@@ -218,7 +218,7 @@ hash_append(Hasher& h, T t) noexcept
 }
 
 template <class Hasher, class T>
-inline std::enable_if_t<std::is_floating_point_v<T>>
+inline std::enable_if_t<std::is_floating_point<T>::value>
 hash_append(Hasher& h, T t) noexcept
 {
     if (t == 0)

include/xrpl/beast/hash/xxhasher.h

@@ -121,13 +121,13 @@ public:
         }
     }
 
-    template <class Seed, std::enable_if_t<std::is_unsigned_v<Seed>>* = nullptr>
+    template <class Seed, std::enable_if_t<std::is_unsigned<Seed>::value>* = nullptr>
     explicit xxhasher(Seed seed) : seed_(seed)
     {
         resetBuffers();
     }
 
-    template <class Seed, std::enable_if_t<std::is_unsigned_v<Seed>>* = nullptr>
+    template <class Seed, std::enable_if_t<std::is_unsigned<Seed>::value>* = nullptr>
     xxhasher(Seed seed, Seed) : seed_(seed)
     {
         resetBuffers();

include/xrpl/beast/insight/Collector.h

@@ -8,7 +8,8 @@
 
 #include <string>
 
-namespace beast::insight {
+namespace beast {
+namespace insight {
 
 /** Interface for a manager that allows collection of metrics.
 
@@ -116,4 +117,5 @@ public:
     /** @} */
 };
 
-}  // namespace beast::insight
+}  // namespace insight
+}  // namespace beast

include/xrpl/beast/insight/Counter.h

@@ -4,7 +4,8 @@
 
 #include <memory>
 
-namespace beast::insight {
+namespace beast {
+namespace insight {
 
 /** A metric for measuring an integral value.
 
@@ -22,7 +23,9 @@ public:
     /** Create a null metric.
         A null metric reports no information.
     */
-    Counter() = default;
+    Counter()
+    {
+    }
 
     /** Create the metric reference the specified implementation.
         Normally this won't be called directly. Instead, call the appropriate
@@ -88,4 +91,5 @@ private:
     std::shared_ptr<CounterImpl> m_impl;
 };
 
-}  // namespace beast::insight
+}  // namespace insight
+}  // namespace beast

include/xrpl/beast/insight/CounterImpl.h

@@ -3,7 +3,8 @@
 #include <cstdint>
 #include <memory>
 
-namespace beast::insight {
+namespace beast {
+namespace insight {
 
 class Counter;
 
@@ -17,4 +18,5 @@ public:
     increment(value_type amount) = 0;
 };
 
-}  // namespace beast::insight
+}  // namespace insight
+}  // namespace beast

include/xrpl/beast/insight/Event.h

@@ -5,7 +5,8 @@
 #include <chrono>
 #include <memory>
 
-namespace beast::insight {
+namespace beast {
+namespace insight {
 
 /** A metric for reporting event timing.
 
@@ -24,7 +25,9 @@ public:
     /** Create a null metric.
         A null metric reports no information.
     */
-    Event() = default;
+    Event()
+    {
+    }
 
     /** Create the metric reference the specified implementation.
         Normally this won't be called directly. Instead, call the appropriate
@@ -55,4 +58,5 @@ private:
     std::shared_ptr<EventImpl> m_impl;
 };
 
-}  // namespace beast::insight
+}  // namespace insight
+}  // namespace beast

include/xrpl/beast/insight/EventImpl.h

@@ -3,7 +3,8 @@
 #include <chrono>
 #include <memory>
 
-namespace beast::insight {
+namespace beast {
+namespace insight {
 
 class Event;
 
@@ -17,4 +18,5 @@ public:
     notify(value_type const& value) = 0;
 };
 
-}  // namespace beast::insight
+}  // namespace insight
+}  // namespace beast

include/xrpl/beast/insight/Gauge.h

@@ -4,7 +4,8 @@
 
 #include <memory>
 
-namespace beast::insight {
+namespace beast {
+namespace insight {
 
 /** A metric for measuring an integral value.
 
@@ -24,7 +25,9 @@ public:
     /** Create a null metric.
         A null metric reports no information.
     */
-    Gauge() = default;
+    Gauge()
+    {
+    }
 
     /** Create the metric reference the specified implementation.
         Normally this won't be called directly. Instead, call the appropriate
@@ -118,4 +121,5 @@ private:
     std::shared_ptr<GaugeImpl> m_impl;
 };
 
-}  // namespace beast::insight
+}  // namespace insight
+}  // namespace beast

include/xrpl/beast/insight/GaugeImpl.h

@@ -3,7 +3,8 @@
 #include <cstdint>
 #include <memory>
 
-namespace beast::insight {
+namespace beast {
+namespace insight {
 
 class Gauge;
 
@@ -20,4 +21,5 @@ public:
     increment(difference_type amount) = 0;
 };
 
-}  // namespace beast::insight
+}  // namespace insight
+}  // namespace beast

include/xrpl/beast/insight/Group.h

@@ -5,7 +5,8 @@
 #include <memory>
 #include <string>
 
-namespace beast::insight {
+namespace beast {
+namespace insight {
 
 /** A collector front-end that manages a group of metrics. */
 class Group : public Collector
@@ -18,4 +19,5 @@ public:
     name() const = 0;
 };
 
-}  // namespace beast::insight
+}  // namespace insight
+}  // namespace beast

include/xrpl/beast/insight/Groups.h

@@ -6,7 +6,8 @@
 #include <memory>
 #include <string>
 
-namespace beast::insight {
+namespace beast {
+namespace insight {
 
 /** A container for managing a set of metric groups. */
 class Groups
@@ -31,4 +32,5 @@ public:
 std::unique_ptr<Groups>
 make_Groups(Collector::ptr const& collector);
 
-}  // namespace beast::insight
+}  // namespace insight
+}  // namespace beast

include/xrpl/beast/insight/Hook.h

@@ -4,7 +4,8 @@
 
 #include <memory>
 
-namespace beast::insight {
+namespace beast {
+namespace insight {
 
 /** A reference to a handler for performing polled collection. */
 class Hook final
@@ -13,7 +14,9 @@ public:
     /** Create a null hook.
         A null hook has no associated handler.
     */
-    Hook() = default;
+    Hook()
+    {
+    }
 
     /** Create a hook referencing the specified implementation.
         Normally this won't be called directly. Instead, call the appropriate
@@ -34,4 +37,5 @@ private:
     std::shared_ptr<HookImpl> m_impl;
 };
 
-}  // namespace beast::insight
+}  // namespace insight
+}  // namespace beast

include/xrpl/beast/insight/HookImpl.h

@@ -3,7 +3,8 @@
 #include <functional>
 #include <memory>
 
-namespace beast::insight {
+namespace beast {
+namespace insight {
 
 class HookImpl : public std::enable_shared_from_this<HookImpl>
 {
@@ -13,4 +14,5 @@ public:
     virtual ~HookImpl() = 0;
 };
 
-}  // namespace beast::insight
+}  // namespace insight
+}  // namespace beast

include/xrpl/beast/insight/Meter.h

@@ -4,7 +4,8 @@
 
 #include <memory>
 
-namespace beast::insight {
+namespace beast {
+namespace insight {
 
 /** A metric for measuring an integral value.
 
@@ -21,7 +22,9 @@ public:
     /** Create a null metric.
         A null metric reports no information.
     */
-    Meter() = default;
+    Meter()
+    {
+    }
 
     /** Create the metric reference the specified implementation.
         Normally this won't be called directly. Instead, call the appropriate
@@ -73,4 +76,5 @@ private:
     std::shared_ptr<MeterImpl> m_impl;
 };
 
-}  // namespace beast::insight
+}  // namespace insight
+}  // namespace beast

include/xrpl/beast/insight/MeterImpl.h

@@ -3,7 +3,8 @@
 #include <cstdint>
 #include <memory>
 
-namespace beast::insight {
+namespace beast {
+namespace insight {
 
 class Meter;
 
@@ -17,4 +18,5 @@ public:
     increment(value_type amount) = 0;
 };
 
-}  // namespace beast::insight
+}  // namespace insight
+}  // namespace beast

include/xrpl/beast/insight/NullCollector.h

@@ -2,7 +2,8 @@
 
 #include <xrpl/beast/insight/Collector.h>
 
-namespace beast::insight {
+namespace beast {
+namespace insight {
 
 /** A Collector which does not collect metrics. */
 class NullCollector : public Collector
@@ -14,4 +15,5 @@ public:
     New();
 };
 
-}  // namespace beast::insight
+}  // namespace insight
+}  // namespace beast

include/xrpl/beast/insight/StatsDCollector.h

@@ -4,7 +4,8 @@
 #include <xrpl/beast/net/IPEndpoint.h>
 #include <xrpl/beast/utility/Journal.h>
 
-namespace beast::insight {
+namespace beast {
+namespace insight {
 
 /** A Collector that reports metrics to a StatsD server.
     Reference:
@@ -24,4 +25,5 @@ public:
     New(IP::Endpoint const& address, std::string const& prefix, Journal journal);
 };
 
-}  // namespace beast::insight
+}  // namespace insight
+}  // namespace beast

include/xrpl/beast/net/IPAddressConversion.h

@@ -4,7 +4,8 @@
 
 #include <boost/asio.hpp>
 
-namespace beast::IP {
+namespace beast {
+namespace IP {
 
 /** Convert to Endpoint.
     The port is set to zero.
@@ -26,7 +27,8 @@ to_asio_address(Endpoint const& endpoint);
 boost::asio::ip::tcp::endpoint
 to_asio_endpoint(Endpoint const& endpoint);
 
-}  // namespace beast::IP
+}  // namespace IP
+}  // namespace beast
 
 namespace beast {
 

include/xrpl/beast/net/IPAddressV4.h

@@ -4,7 +4,8 @@
 
 #include <boost/asio/ip/address_v4.hpp>
 
-namespace beast::IP {
+namespace beast {
+namespace IP {
 
 using AddressV4 = boost::asio::ip::address_v4;
 
@@ -22,4 +23,5 @@ is_public(AddressV4 const& addr);
 char
 get_class(AddressV4 const& address);
 
-}  // namespace beast::IP
+}  // namespace IP
+}  // namespace beast

include/xrpl/beast/net/IPAddressV6.h

@@ -4,7 +4,8 @@
 
 #include <boost/asio/ip/address_v6.hpp>
 
-namespace beast::IP {
+namespace beast {
+namespace IP {
 
 using AddressV6 = boost::asio::ip::address_v6;
 
@@ -16,4 +17,5 @@ is_private(AddressV6 const& addr);
 bool
 is_public(AddressV6 const& addr);
 
-}  // namespace beast::IP
+}  // namespace IP
+}  // namespace beast

include/xrpl/beast/net/IPEndpoint.h

@@ -8,7 +8,8 @@
 #include <optional>
 #include <string>
 
-namespace beast::IP {
+namespace beast {
+namespace IP {
 
 using Port = std::uint16_t;
 
@@ -20,7 +21,7 @@ public:
     Endpoint();
 
     /** Create an endpoint from the address and optional port. */
-    explicit Endpoint(Address addr, Port port = 0);
+    explicit Endpoint(Address const& addr, Port port = 0);
 
     /** Create an Endpoint from a string.
         If the port is omitted, the endpoint will have a zero port.
@@ -183,7 +184,8 @@ operator<<(OutputStream& os, Endpoint const& endpoint)
 std::istream&
 operator>>(std::istream& is, Endpoint& endpoint);
 
-}  // namespace beast::IP
+}  // namespace IP
+}  // namespace beast
 
 //------------------------------------------------------------------------------
 

include/xrpl/beast/rfc2616.h

@@ -12,7 +12,8 @@
 #include <string>
 #include <vector>
 
-namespace beast::rfc2616 {
+namespace beast {
+namespace rfc2616 {
 
 namespace detail {
 
@@ -369,4 +370,5 @@ is_keep_alive(boost::beast::http::message<isRequest, Body, Fields> const& m)
         "close");
 }
 
-}  // namespace beast::rfc2616
+}  // namespace rfc2616
+}  // namespace beast

include/xrpl/beast/test/yield_to.h

@@ -15,7 +15,8 @@
 #include <thread>
 #include <vector>
 
-namespace beast::test {
+namespace beast {
+namespace test {
 
 /** Mix-in to support tests using asio coroutines.
 
@@ -124,4 +125,5 @@ enable_yield_to::spawn(F0&& f, FN&&... fn)
     spawn(fn...);
 }
 
-}  // namespace beast::test
+}  // namespace test
+}  // namespace beast

include/xrpl/beast/type_name.h

@@ -15,7 +15,7 @@ template <typename T>
 std::string
 type_name()
 {
-    using TR = std::remove_reference_t<T>;
+    using TR = typename std::remove_reference<T>::type;
 
     std::string name = typeid(TR).name();
 
@@ -27,15 +27,15 @@ type_name()
     }
 #endif
 
-    if (std::is_const_v<TR>)
+    if (std::is_const<TR>::value)
         name += " const";
-    if (std::is_volatile_v<TR>)
+    if (std::is_volatile<TR>::value)
         name += " volatile";
-    if (std::is_lvalue_reference_v<T>)
+    if (std::is_lvalue_reference<T>::value)
     {
         name += "&";
     }
-    else if (std::is_rvalue_reference_v<T>)
+    else if (std::is_rvalue_reference<T>::value)
     {
         name += "&&";
     }

include/xrpl/beast/unit_test/amount.h

@@ -8,7 +8,8 @@
 #include <ostream>
 #include <string>
 
-namespace beast::unit_test {
+namespace beast {
+namespace unit_test {
 
 /** Utility for producing nicely composed output of amounts with units. */
 class amount
@@ -41,4 +42,5 @@ operator<<(std::ostream& s, amount const& t)
     return s;
 }
 
-}  // namespace beast::unit_test
+}  // namespace unit_test
+}  // namespace beast

include/xrpl/beast/unit_test/detail/const_container.h

@@ -4,7 +4,9 @@
 
 #pragma once
 
-namespace beast::unit_test::detail {
+namespace beast {
+namespace unit_test {
+namespace detail {
 
 /** Adapter to constrain a container interface.
     The interface allows for limited read only operations. Derived classes
@@ -80,4 +82,6 @@ public:
     /** @} */
 };
 
-}  // namespace beast::unit_test::detail
+}  // namespace detail
+}  // namespace unit_test
+}  // namespace beast

include/xrpl/beast/unit_test/global_suites.h

@@ -6,7 +6,8 @@
 
 #include <xrpl/beast/unit_test/suite_list.h>
 
-namespace beast::unit_test {
+namespace beast {
+namespace unit_test {
 
 namespace detail {
 
@@ -41,4 +42,5 @@ global_suites()
     return detail::global_suites();
 }
 
-}  // namespace beast::unit_test
+}  // namespace unit_test
+}  // namespace beast

include/xrpl/beast/unit_test/match.h

@@ -8,7 +8,8 @@
 
 #include <string>
 
-namespace beast::unit_test {
+namespace beast {
+namespace unit_test {
 
 // Predicate for implementing matches
 class selector
@@ -162,4 +163,5 @@ match_library(std::string const& name)
     return selector(selector::library, name);
 }
 
-}  // namespace beast::unit_test
+}  // namespace unit_test
+}  // namespace beast

include/xrpl/beast/unit_test/recorder.h

@@ -7,7 +7,8 @@
 #include <xrpl/beast/unit_test/results.h>
 #include <xrpl/beast/unit_test/runner.h>
 
-namespace beast::unit_test {
+namespace beast {
+namespace unit_test {
 
 /** A test runner that stores the results. */
 class recorder : public runner
@@ -28,48 +29,49 @@ public:
     }
 
 private:
-    void
+    virtual void
     on_suite_begin(suite_info const& info) override
     {
         m_suite = suite_results(info.full_name());
     }
 
-    void
+    virtual void
     on_suite_end() override
     {
         m_results.insert(std::move(m_suite));
     }
 
-    void
+    virtual void
     on_case_begin(std::string const& name) override
     {
         m_case = case_results(name);
     }
 
-    void
+    virtual void
     on_case_end() override
     {
         if (!m_case.tests.empty())
             m_suite.insert(std::move(m_case));
     }
 
-    void
+    virtual void
     on_pass() override
     {
         m_case.tests.pass();
     }
 
-    void
+    virtual void
     on_fail(std::string const& reason) override
     {
         m_case.tests.fail(reason);
     }
 
-    void
+    virtual void
     on_log(std::string const& s) override
     {
         m_case.log.insert(s);
     }
 };
 
-}  // namespace beast::unit_test
+}  // namespace unit_test
+}  // namespace beast

include/xrpl/beast/unit_test/reporter.h

@@ -18,7 +18,8 @@
 #include <string>
 #include <utility>
 
-namespace beast::unit_test {
+namespace beast {
+namespace unit_test {
 
 namespace detail {
 
@@ -85,7 +86,7 @@ public:
     reporter&
     operator=(reporter const&) = delete;
 
-    ~reporter() override;
+    ~reporter();
 
     explicit reporter(std::ostream& os = std::cout);
 
@@ -93,25 +94,25 @@ private:
     static std::string
     fmtdur(typename clock_type::duration const& d);
 
-    void
+    virtual void
     on_suite_begin(suite_info const& info) override;
 
-    void
+    virtual void
     on_suite_end() override;
 
-    void
+    virtual void
     on_case_begin(std::string const& name) override;
 
-    void
+    virtual void
     on_case_end() override;
 
-    void
+    virtual void
     on_pass() override;
 
-    void
+    virtual void
     on_fail(std::string const& reason) override;
 
-    void
+    virtual void
     on_log(std::string const& s) override;
 };
 
@@ -250,4 +251,5 @@ reporter<Unused>::on_log(std::string const& s)
 
 using reporter = detail::reporter<>;
 
-}  // namespace beast::unit_test
+}  // namespace unit_test
+}  // namespace beast

include/xrpl/beast/unit_test/results.h

@@ -7,10 +7,10 @@
 #include <xrpl/beast/unit_test/detail/const_container.h>
 
 #include <string>
-#include <utility>
 #include <vector>
 
-namespace beast::unit_test {
+namespace beast {
+namespace unit_test {
 
 /** Holds a set of test condition outcomes in a testcase. */
 class case_results
@@ -23,7 +23,7 @@ public:
         {
         }
 
-        test(bool pass_, std::string reason_) : pass(pass_), reason(std::move(reason_))
+        test(bool pass_, std::string const& reason_) : pass(pass_), reason(reason_)
         {
         }
 
@@ -38,7 +38,9 @@ private:
         std::size_t failed_{0};
 
     public:
-        tests_t() = default;
+        tests_t()
+        {
+        }
 
         /** Returns the total number of test conditions. */
         std::size_t
@@ -84,7 +86,7 @@ private:
     std::string name_;
 
 public:
-    explicit case_results(std::string name = "") : name_(std::move(name))
+    explicit case_results(std::string const& name = "") : name_(name)
     {
     }
 
@@ -113,7 +115,7 @@ private:
     std::size_t failed_ = 0;
 
 public:
-    explicit suite_results(std::string name = "") : name_(std::move(name))
+    explicit suite_results(std::string const& name = "") : name_(name)
     {
     }
 
@@ -170,7 +172,9 @@ private:
     std::size_t failed_{0};
 
 public:
-    results() = default;
+    results()
+    {
+    }
 
     /** Returns the total number of test cases. */
     std::size_t
@@ -215,4 +219,5 @@ public:
     /** @} */
 };
 
-}  // namespace beast::unit_test
+}  // namespace unit_test
+}  // namespace beast

include/xrpl/beast/unit_test/runner.h

@@ -11,7 +11,8 @@
 #include <mutex>
 #include <string>
 
-namespace beast::unit_test {
+namespace beast {
+namespace unit_test {
 
 /** Unit test runner interface.
 
@@ -276,4 +277,5 @@ runner::log(std::string const& s)
     on_log(s);
 }
 
-}  // namespace beast::unit_test
+}  // namespace unit_test
+}  // namespace beast

include/xrpl/beast/unit_test/suite.h

@@ -14,7 +14,8 @@
 #include <sstream>
 #include <string>
 
-namespace beast::unit_test {
+namespace beast {
+namespace unit_test {
 
 namespace detail {
 
@@ -74,7 +75,7 @@ private:
         {
         }
 
-        ~log_buf() override
+        ~log_buf()
         {
             sync();
         }
@@ -572,7 +573,8 @@ suite::run(runner& r)
     ((cond) ? (pass(), true) : (fail((reason), __FILE__, __LINE__), false))
 #endif
 
-}  // namespace beast::unit_test
+}  // namespace unit_test
+}  // namespace beast
 
 //------------------------------------------------------------------------------
 

include/xrpl/beast/unit_test/suite_info.h

@@ -9,7 +9,8 @@
 #include <string>
 #include <utility>
 
-namespace beast::unit_test {
+namespace beast {
+namespace unit_test {
 
 class runner;
 
@@ -109,4 +110,5 @@ make_suite_info(
         });
 }
 
-}  // namespace beast::unit_test
+}  // namespace unit_test
+}  // namespace beast

include/xrpl/beast/unit_test/suite_list.h

@@ -13,7 +13,8 @@
 #include <typeindex>
 #include <unordered_set>
 
-namespace beast::unit_test {
+namespace beast {
+namespace unit_test {
 
 /// A container of test suites.
 class suite_list : public detail::const_container<std::set<suite_info>>
@@ -61,4 +62,5 @@ suite_list::insert(
     cont().emplace(make_suite_info<Suite>(name, module, library, manual, priority));
 }
 
-}  // namespace beast::unit_test
+}  // namespace unit_test
+}  // namespace beast

include/xrpl/beast/unit_test/thread.h

@@ -10,7 +10,8 @@
 #include <thread>
 #include <utility>
 
-namespace beast::unit_test {
+namespace beast {
+namespace unit_test {
 
 /** Replacement for std::thread that handles exceptions in unit tests. */
 class Thread
@@ -107,4 +108,5 @@ private:
     }
 };
 
-}  // namespace beast::unit_test
+}  // namespace unit_test
+}  // namespace beast

include/xrpl/beast/utility/Journal.h

@@ -55,16 +55,15 @@ public:
     class Sink
     {
     protected:
+        Sink() = delete;
         explicit Sink(Sink const& sink) = default;
         Sink(Severity thresh, bool console);
+        Sink&
+        operator=(Sink const& lhs) = delete;
 
     public:
         virtual ~Sink() = 0;
 
-        Sink() = delete;
-        Sink&
-        operator=(Sink const& lhs) = delete;
-
         /** Returns `true` if text at the passed severity produces output. */
         virtual bool
         active(Severity level) const;
@@ -372,6 +371,10 @@ class logstream_buf : public std::basic_stringbuf<CharT, Traits>
 {
     beast::Journal::Stream strm_;
 
+    template <class T>
+    void
+    write(T const*) = delete;
+
     void
     write(char const* s)
     {
@@ -391,7 +394,7 @@ public:
     {
     }
 
-    ~logstream_buf() override
+    ~logstream_buf()
     {
         sync();
     }
@@ -403,10 +406,6 @@ public:
         this->str("");
         return 0;
     }
-
-    template <class T>
-    void
-    write(T const*) = delete;
 };
 
 }  // namespace detail
@@ -414,11 +413,11 @@ public:
 template <class CharT, class Traits = std::char_traits<CharT>>
 class basic_logstream : public std::basic_ostream<CharT, Traits>
 {
-    using char_type = CharT;
-    using traits_type = Traits;
-    using int_type = typename traits_type::int_type;
-    using pos_type = typename traits_type::pos_type;
-    using off_type = typename traits_type::off_type;
+    typedef CharT char_type;
+    typedef Traits traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
 
     detail::logstream_buf<CharT, Traits> buf_;
 

include/xrpl/beast/utility/PropertyStream.h

@@ -174,7 +174,7 @@ private:
     std::ostringstream mutable m_ostream;
 
 public:
-    Proxy(Map const& map, std::string key);
+    Proxy(Map const& map, std::string const& key);
     Proxy(Proxy const& other);
     ~Proxy();
 
@@ -315,7 +315,7 @@ private:
     List<Item> children_;
 
 public:
-    explicit Source(std::string name);
+    explicit Source(std::string const& name);
     virtual ~Source();
 
     Source(Source const&) = delete;

include/xrpl/beast/utility/WrappedSink.h

@@ -2,8 +2,6 @@
 
 #include <xrpl/beast/utility/Journal.h>
 
-#include <utility>
-
 namespace beast {
 
 /** Wraps a Journal::Sink to prefix its output with a string. */
@@ -19,8 +17,8 @@ private:
     std::string prefix_;
 
 public:
-    explicit WrappedSink(beast::Journal::Sink& sink, std::string prefix = "")
-        : Sink(sink), sink_(sink), prefix_(std::move(prefix))
+    explicit WrappedSink(beast::Journal::Sink& sink, std::string const& prefix = "")
+        : Sink(sink), sink_(sink), prefix_(prefix)
     {
     }
 

include/xrpl/beast/utility/Zero.h

@@ -38,7 +38,8 @@ signum(T const& t)
     return t.signum();
 }
 
-namespace detail::zero_helper {
+namespace detail {
+namespace zero_helper {
 
 // For argument dependent lookup to function properly, calls to signum must
 // be made from a namespace that does not include overloads of the function..
@@ -49,7 +50,8 @@ call_signum(T const& t)
     return signum(t);
 }
 
-}  // namespace detail::zero_helper
+}  // namespace zero_helper
+}  // namespace detail
 
 // Handle operators where T is on the left side using signum.
 

include/xrpl/beast/utility/maybe_const.h

@@ -9,8 +9,10 @@ template <bool IsConst, class T>
 struct maybe_const
 {
     explicit maybe_const() = default;
-    using type = std::
-        conditional_t<IsConst, typename std::remove_const<T>::type const, std::remove_const_t<T>>;
+    using type = typename std::conditional<
+        IsConst,
+        typename std::remove_const<T>::type const,
+        typename std::remove_const<T>::type>::type;
 };
 
 /** Alias for omitting `typename`. */

include/xrpl/conditions/Condition.h

@@ -7,7 +7,8 @@
 #include <cstdint>
 #include <set>
 
-namespace xrpl::cryptoconditions {
+namespace xrpl {
+namespace cryptoconditions {
 
 enum class Type : std::uint8_t {
     preimageSha256 = 0,
@@ -87,4 +88,6 @@ operator!=(Condition const& lhs, Condition const& rhs)
     return !(lhs == rhs);
 }
 
-}  // namespace xrpl::cryptoconditions
+}  // namespace cryptoconditions
+
+}  // namespace xrpl

include/xrpl/conditions/Fulfillment.h

@@ -4,7 +4,8 @@
 #include <xrpl/basics/Slice.h>
 #include <xrpl/conditions/Condition.h>
 
-namespace xrpl::cryptoconditions {
+namespace xrpl {
+namespace cryptoconditions {
 
 struct Fulfillment
 {
@@ -118,4 +119,5 @@ validate(Fulfillment const& f, Condition const& c, Slice m);
 bool
 validate(Fulfillment const& f, Condition const& c);
 
-}  // namespace xrpl::cryptoconditions
+}  // namespace cryptoconditions
+}  // namespace xrpl

include/xrpl/conditions/detail/PreimageSha256.h

@@ -9,7 +9,8 @@
 
 #include <memory>
 
-namespace xrpl::cryptoconditions {
+namespace xrpl {
+namespace cryptoconditions {
 
 class PreimageSha256 final : public Fulfillment
 {
@@ -126,4 +127,5 @@ public:
     }
 };
 
-}  // namespace xrpl::cryptoconditions
+}  // namespace cryptoconditions
+}  // namespace xrpl

include/xrpl/conditions/detail/error.h

@@ -2,7 +2,8 @@
 
 #include <system_error>
 
-namespace xrpl::cryptoconditions {
+namespace xrpl {
+namespace cryptoconditions {
 
 enum class error {
     generic = 1,
@@ -27,7 +28,8 @@ enum class error {
 std::error_code
 make_error_code(error ev);
 
-}  // namespace xrpl::cryptoconditions
+}  // namespace cryptoconditions
+}  // namespace xrpl
 
 namespace std {
 

include/xrpl/conditions/detail/utils.h

@@ -8,12 +8,15 @@
 
 #include <limits>
 
+namespace xrpl {
+namespace cryptoconditions {
+
 // A collection of functions to decode binary blobs
 // encoded with X.690 Distinguished Encoding Rules.
 //
 // This is a very trivial decoder and only implements
 // the bare minimum needed to support PreimageSha256.
-namespace xrpl::cryptoconditions::der {
+namespace der {
 
 // The preamble encapsulates the DER identifier and
 // length octets:
@@ -201,4 +204,6 @@ parseInteger(Slice& s, std::size_t count, std::error_code& ec)
     return v;
 }
 
-}  // namespace xrpl::cryptoconditions::der
+}  // namespace der
+}  // namespace cryptoconditions
+}  // namespace xrpl

include/xrpl/core/ClosureCounter.h

@@ -75,7 +75,7 @@ private:
         std::remove_reference_t<Closure> closure_;
 
         static_assert(
-            std::is_same_v<decltype(closure_(std::declval<Args_t>()...)), Ret_t>,
+            std::is_same<decltype(closure_(std::declval<Args_t>()...)), Ret_t>::value,
             "Closure arguments don't match ClosureCounter Ret_t or Args_t");
 
     public:
@@ -86,7 +86,7 @@ private:
             ++counter_;
         }
 
-        Substitute(Substitute&& rhs) noexcept(std::is_nothrow_move_constructible_v<Closure>)
+        Substitute(Substitute&& rhs) noexcept(std::is_nothrow_move_constructible<Closure>::value)
             : counter_(rhs.counter_), closure_(std::move(rhs.closure_))
         {
             ++counter_;

include/xrpl/core/HashRouter.h

@@ -109,7 +109,9 @@ private:
     class Entry : public CountedObject<Entry>
     {
     public:
-        Entry() = default;
+        Entry()
+        {
+        }
 
         void
         addPeer(PeerShortID peer)
@@ -137,13 +139,6 @@ private:
             return std::move(peers_);
         }
 
-        /** Return set of peers waiting for reply. Leaves list unchanged. */
-        std::set<PeerShortID> const&
-        peekPeerSet()
-        {
-            return peers_;
-        }
-
         /** Return seated relay time point if the message has been relayed */
         std::optional<Stopwatch::time_point>
         relayed() const
@@ -175,20 +170,6 @@ private:
             return true;
         }
 
-        bool
-        shouldProcessForPeer(
-            PeerShortID peer,
-            Stopwatch::time_point now,
-            std::chrono::seconds interval)
-        {
-            if (peerProcessed_.contains(peer) && ((peerProcessed_[peer] + interval) > now))
-                return false;
-            // Peer may already be in the list, but adding it again doesn't hurt
-            addPeer(peer);
-            peerProcessed_[peer] = now;
-            return true;
-        }
-
     private:
         HashRouterFlags flags_ = HashRouterFlags::UNDEFINED;
         std::set<PeerShortID> peers_;
@@ -196,7 +177,6 @@ private:
         // than one flag needs to expire independently.
         std::optional<Stopwatch::time_point> relayed_;
         std::optional<Stopwatch::time_point> processed_;
-        std::map<PeerShortID, Stopwatch::time_point> peerProcessed_;
     };
 
 public:
@@ -219,7 +199,7 @@ public:
 
     /** Add a suppression peer and get message's relay status.
      * Return pair:
-     * element 1: true if the key is added.
+     * element 1: true if the peer is added.
      * element 2: optional is seated to the relay time point or
      * is unseated if has not relayed yet. */
     std::pair<bool, std::optional<Stopwatch::time_point>>
@@ -236,15 +216,6 @@ public:
         HashRouterFlags& flags,
         std::chrono::seconds tx_interval);
 
-    /** Determines whether the hashed item should be processed for the given
-       peer. Could be an incoming or outgoing message.
-
-       Items filtered with this function should only be processed for the given
-       peer once. Unlike shouldProcess, it can be processed for other peers.
-     */
-    bool
-    shouldProcessForPeer(uint256 const& key, PeerShortID peer, std::chrono::seconds interval);
-
     /** Set the flags on a hash.
 
         @return `true` if the flags were changed. `false` if unchanged.
@@ -270,11 +241,6 @@ public:
     std::optional<std::set<PeerShortID>>
     shouldRelay(uint256 const& key);
 
-    /** Returns a copy of the set of peers in the Entry for the key
-     */
-    std::set<PeerShortID>
-    getPeers(uint256 const& key);
-
 private:
     // pair.second indicates whether the entry was created
     std::pair<Entry&, bool>

include/xrpl/core/JobQueue.h

@@ -128,7 +128,7 @@ public:
         beast::Journal journal,
         Logs& logs,
         perf::PerfLog& perfLog);
-    ~JobQueue() override;
+    ~JobQueue();
 
     /** Adds a job to the JobQueue.
 
@@ -141,7 +141,8 @@ public:
     */
     template <
         typename JobHandler,
-        typename = std::enable_if_t<std::is_same_v<decltype(std::declval<JobHandler&&>()()), void>>>
+        typename =
+            std::enable_if_t<std::is_same<decltype(std::declval<JobHandler&&>()()), void>::value>>
     bool
     addJob(JobType type, std::string const& name, JobHandler&& jobHandler)
     {

include/xrpl/core/JobTypeData.h

@@ -4,8 +4,6 @@
 #include <xrpl/beast/insight/Collector.h>
 #include <xrpl/core/JobTypeInfo.h>
 
-#include <utility>
-
 namespace xrpl {
 
 struct JobTypeData
@@ -35,9 +33,9 @@ public:
 
     JobTypeData(
         JobTypeInfo const& info_,
-        beast::insight::Collector::ptr collector,
+        beast::insight::Collector::ptr const& collector,
         Logs& logs) noexcept
-        : m_load(logs.journal("LoadMonitor")), m_collector(std::move(collector)), info(info_)
+        : m_load(logs.journal("LoadMonitor")), m_collector(collector), info(info_)
 
     {
         m_load.setTargetLatency(info.getAverageLatency(), info.getPeakLatency());

include/xrpl/core/LoadEvent.h

@@ -16,7 +16,7 @@ class LoadEvent
 {
 public:
     // VFALCO TODO remove the dependency on LoadMonitor. Is that possible?
-    LoadEvent(LoadMonitor& monitor, std::string name, bool shouldStart);
+    LoadEvent(LoadMonitor& monitor, std::string const& name, bool shouldStart);
     LoadEvent(LoadEvent const&) = delete;
 
     ~LoadEvent();

include/xrpl/core/detail/Workers.h

@@ -93,7 +93,7 @@ public:
     explicit Workers(
         Callback& callback,
         perf::PerfLog* perfLog,
-        std::string threadNames = "Worker",
+        std::string const& threadNames = "Worker",
         int numberOfThreads = static_cast<int>(std::thread::hardware_concurrency()));
 
     ~Workers();
@@ -164,7 +164,7 @@ private:
                    public beast::LockFreeStack<Worker, PausedTag>::Node
     {
     public:
-        Worker(Workers& workers, std::string threadName, int const instance);
+        Worker(Workers& workers, std::string const& threadName, int const instance);
 
         ~Worker();
 

include/xrpl/json/json_writer.h

@@ -15,7 +15,9 @@ class Value;
 class WriterBase
 {
 public:
-    virtual ~WriterBase() = default;
+    virtual ~WriterBase()
+    {
+    }
     virtual std::string
     write(Value const& root) = 0;
 };
@@ -32,7 +34,9 @@ class FastWriter : public WriterBase
 {
 public:
     FastWriter() = default;
-    ~FastWriter() override = default;
+    virtual ~FastWriter()
+    {
+    }
 
 public:  // overridden from Writer
     std::string
@@ -67,7 +71,9 @@ class StyledWriter : public WriterBase
 {
 public:
     StyledWriter();
-    ~StyledWriter() override = default;
+    virtual ~StyledWriter()
+    {
+    }
 
 public:  // overridden from Writer
     /** \brief Serialize a Value in <a HREF="http://www.json.org">JSON</a>
@@ -130,7 +136,9 @@ class StyledStreamWriter
 {
 public:
     StyledStreamWriter(std::string indentation = "\t");
-    ~StyledStreamWriter() = default;
+    ~StyledStreamWriter()
+    {
+    }
 
 public:
     /** \brief Serialize a Value in <a HREF="http://www.json.org">JSON</a>

include/xrpl/ledger/AmendmentTable.h

@@ -8,7 +8,6 @@
 #include <xrpl/shamap/SHAMap.h>
 
 #include <optional>
-#include <utility>
 
 namespace xrpl {
 
@@ -24,8 +23,8 @@ public:
     struct FeatureInfo
     {
         FeatureInfo() = delete;
-        FeatureInfo(std::string n, uint256 const& f, VoteBehavior v)
-            : name(std::move(n)), feature(f), vote(v)
+        FeatureInfo(std::string const& n, uint256 const& f, VoteBehavior v)
+            : name(n), feature(f), vote(v)
         {
         }
 

include/xrpl/ledger/BookListeners.h

@@ -14,7 +14,9 @@ class BookListeners
 public:
     using pointer = std::shared_ptr<BookListeners>;
 
-    BookListeners() = default;
+    BookListeners()
+    {
+    }
 
     /** Add a new subscription for this book
      */

include/xrpl/ledger/CachedView.h

@@ -132,7 +132,7 @@ template <class Base>
 class CachedView : public detail::CachedViewImpl
 {
 private:
-    static_assert(std::is_base_of_v<DigestAwareReadView, Base>, "");
+    static_assert(std::is_base_of<DigestAwareReadView, Base>::value, "");
 
     std::shared_ptr<Base const> sp_;
 

include/xrpl/ledger/Ledger.h

@@ -82,12 +82,12 @@ public:
     */
     Ledger(
         create_genesis_t,
-        Rules rules,
+        Rules const& rules,
         Fees const& fees,
         std::vector<uint256> const& amendments,
         Family& family);
 
-    Ledger(LedgerHeader const& info, Rules rules, Family& family);
+    Ledger(LedgerHeader const& info, Rules const& rules, Family& family);
 
     /** Used for ledgers loaded from JSON files
 
@@ -100,7 +100,7 @@ public:
         LedgerHeader const& info,
         bool& loaded,
         bool acquire,
-        Rules rules,
+        Rules const& rules,
         Fees const& fees,
         Family& family,
         beast::Journal j);
@@ -117,11 +117,11 @@ public:
     Ledger(
         std::uint32_t ledgerSeq,
         NetClock::time_point closeTime,
-        Rules rules,
+        Rules const& rules,
         Fees const& fees,
         Family& family);
 
-    ~Ledger() override = default;
+    ~Ledger() = default;
 
     //
     // ReadView

include/xrpl/ledger/OpenView.h

@@ -135,7 +135,7 @@ public:
     OpenView(
         open_ledger_t,
         ReadView const* base,
-        Rules rules,
+        Rules const& rules,
         std::shared_ptr<void const> hold = nullptr);
 
     OpenView(open_ledger_t, Rules const& rules, std::shared_ptr<ReadView const> const& base)

include/xrpl/ledger/PaymentSandbox.h

@@ -6,7 +6,6 @@
 #include <xrpl/protocol/AccountID.h>
 
 #include <map>
-#include <utility>
 
 namespace xrpl {
 
@@ -64,8 +63,8 @@ private:
 public:
     struct AdjustmentIOU
     {
-        AdjustmentIOU(STAmount d, STAmount c, STAmount b)
-            : debits(std::move(d)), credits(std::move(c)), origBalance(std::move(b))
+        AdjustmentIOU(STAmount const& d, STAmount const& c, STAmount const& b)
+            : debits(d), credits(c), origBalance(b)
         {
         }
         STAmount debits;

include/xrpl/ledger/detail/ApplyStateTable.h

@@ -10,7 +10,8 @@
 
 #include <memory>
 
-namespace xrpl::detail {
+namespace xrpl {
+namespace detail {
 
 // Helper class that buffers modifications
 class ApplyStateTable
@@ -124,4 +125,5 @@ private:
         beast::Journal j);
 };
 
-}  // namespace xrpl::detail
+}  // namespace detail
+}  // namespace xrpl

include/xrpl/ledger/detail/ApplyViewBase.h

@@ -5,7 +5,8 @@
 #include <xrpl/ledger/detail/ApplyStateTable.h>
 #include <xrpl/protocol/XRPAmount.h>
 
-namespace xrpl::detail {
+namespace xrpl {
+namespace detail {
 
 class ApplyViewBase : public ApplyView, public RawView
 {
@@ -101,4 +102,5 @@ protected:
     detail::ApplyStateTable items_;
 };
 
-}  // namespace xrpl::detail
+}  // namespace detail
+}  // namespace xrpl

include/xrpl/ledger/detail/RawStateTable.h

@@ -9,7 +9,8 @@
 #include <map>
 #include <utility>
 
-namespace xrpl::detail {
+namespace xrpl {
+namespace detail {
 
 // Helper class that buffers raw modifications
 class RawStateTable
@@ -107,4 +108,5 @@ private:
     XRPAmount dropsDestroyed_{0};
 };
 
-}  // namespace xrpl::detail
+}  // namespace detail
+}  // namespace xrpl

include/xrpl/ledger/helpers/NFTokenHelpers.h

@@ -8,9 +8,9 @@
 #include <xrpl/protocol/TxFlags.h>
 #include <xrpl/protocol/nft.h>
 
-#include <utility>
+namespace xrpl {
 
-namespace xrpl::nft {
+namespace nft {
 
 /** Delete up to a specified number of offers from the specified token offer
  * directory. */
@@ -30,8 +30,8 @@ struct TokenAndPage
     STObject token;
     std::shared_ptr<SLE> page;
 
-    TokenAndPage(STObject token_, std::shared_ptr<SLE> page_)
-        : token(std::move(token_)), page(std::move(page_))
+    TokenAndPage(STObject const& token_, std::shared_ptr<SLE> page_)
+        : token(token_), page(std::move(page_))
     {
     }
 };
@@ -136,4 +136,6 @@ checkTrustlineDeepFrozen(
     beast::Journal const j,
     Issue const& issue);
 
-}  // namespace xrpl::nft
+}  // namespace nft
+
+}  // namespace xrpl

include/xrpl/ledger/helpers/PermissionedDEXHelpers.h

@@ -1,7 +1,8 @@
 #pragma once
 #include <xrpl/ledger/View.h>
 
-namespace xrpl::permissioned_dex {
+namespace xrpl {
+namespace permissioned_dex {
 
 // Check if an account is in a permissioned domain
 [[nodiscard]] bool
@@ -15,4 +16,6 @@ offerInDomain(
     Domain const& domainID,
     beast::Journal j);
 
-}  // namespace xrpl::permissioned_dex
+}  // namespace permissioned_dex
+
+}  // namespace xrpl

include/xrpl/net/HTTPClientSSLContext.h

@@ -79,8 +79,8 @@ public:
     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&>>>>
+            std::is_same<T, boost::asio::ssl::stream<boost::asio::ip::tcp::socket>>::value ||
+            std::is_same<T, boost::asio::ssl::stream<boost::asio::ip::tcp::socket&>>::value>>
     boost::system::error_code
     preConnectVerify(T& strm, std::string const& host)
     {
@@ -99,8 +99,8 @@ public:
     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&>>>>
+            std::is_same<T, boost::asio::ssl::stream<boost::asio::ip::tcp::socket>>::value ||
+            std::is_same<T, boost::asio::ssl::stream<boost::asio::ip::tcp::socket&>>::value>>
     /**
      * @brief invoked after connect/async_connect but before sending data
      * on an ssl stream - to setup name verification.

include/xrpl/nodestore/Backend.h

@@ -4,7 +4,8 @@
 
 #include <cstdint>
 
-namespace xrpl::NodeStore {
+namespace xrpl {
+namespace NodeStore {
 
 /** A backend used for the NodeStore.
 
@@ -139,4 +140,5 @@ public:
     fdRequired() const = 0;
 };
 
-}  // namespace xrpl::NodeStore
+}  // namespace NodeStore
+}  // namespace xrpl

include/xrpl/nodestore/Database.h

@@ -10,7 +10,9 @@
 
 #include <condition_variable>
 
-namespace xrpl::NodeStore {
+namespace xrpl {
+
+namespace NodeStore {
 
 /** Persistency layer for NodeObject
 
@@ -272,4 +274,5 @@ private:
     threadEntry();
 };
 
-}  // namespace xrpl::NodeStore
+}  // namespace NodeStore
+}  // namespace xrpl

include/xrpl/nodestore/DatabaseRotating.h

@@ -2,7 +2,8 @@
 
 #include <xrpl/nodestore/Database.h>
 
-namespace xrpl::NodeStore {
+namespace xrpl {
+namespace NodeStore {
 
 /* This class has two key-value store Backend objects for persisting SHAMap
  * records. This facilitates online deletion of data. New backends are
@@ -35,4 +36,5 @@ public:
             f) = 0;
 };
 
-}  // namespace xrpl::NodeStore
+}  // namespace NodeStore
+}  // namespace xrpl

include/xrpl/nodestore/DummyScheduler.h

@@ -2,14 +2,15 @@
 
 #include <xrpl/nodestore/Scheduler.h>
 
-namespace xrpl::NodeStore {
+namespace xrpl {
+namespace NodeStore {
 
 /** Simple NodeStore Scheduler that just performs the tasks synchronously. */
 class DummyScheduler : public Scheduler
 {
 public:
     DummyScheduler() = default;
-    ~DummyScheduler() override = default;
+    ~DummyScheduler() = default;
     void
     scheduleTask(Task& task) override;
     void
@@ -18,4 +19,5 @@ public:
     onBatchWrite(BatchWriteReport const& report) override;
 };
 
-}  // namespace xrpl::NodeStore
+}  // namespace NodeStore
+}  // namespace xrpl

include/xrpl/nodestore/Factory.h

@@ -7,7 +7,9 @@
 
 #include <nudb/store.hpp>
 
-namespace xrpl::NodeStore {
+namespace xrpl {
+
+namespace NodeStore {
 
 /** Base class for backend factories. */
 class Factory
@@ -57,4 +59,5 @@ public:
     }
 };
 
-}  // namespace xrpl::NodeStore
+}  // namespace NodeStore
+}  // namespace xrpl

include/xrpl/nodestore/Manager.h

@@ -3,7 +3,9 @@
 #include <xrpl/nodestore/DatabaseRotating.h>
 #include <xrpl/nodestore/Factory.h>
 
-namespace xrpl::NodeStore {
+namespace xrpl {
+
+namespace NodeStore {
 
 /** Singleton for managing NodeStore factories and back ends. */
 class Manager
@@ -79,4 +81,5 @@ public:
         beast::Journal journal) = 0;
 };
 
-}  // namespace xrpl::NodeStore
+}  // namespace NodeStore
+}  // namespace xrpl

include/xrpl/nodestore/Scheduler.h

@@ -4,7 +4,8 @@
 
 #include <chrono>
 
-namespace xrpl::NodeStore {
+namespace xrpl {
+namespace NodeStore {
 
 enum class FetchType { synchronous, async };
 
@@ -63,4 +64,5 @@ public:
     onBatchWrite(BatchWriteReport const& report) = 0;
 };
 
-}  // namespace xrpl::NodeStore
+}  // namespace NodeStore
+}  // namespace xrpl

include/xrpl/nodestore/Task.h

@@ -1,6 +1,7 @@
 #pragma once
 
-namespace xrpl::NodeStore {
+namespace xrpl {
+namespace NodeStore {
 
 /** Derived classes perform scheduled tasks. */
 struct Task
@@ -14,4 +15,5 @@ struct Task
     performScheduledTask() = 0;
 };
 
-}  // namespace xrpl::NodeStore
+}  // namespace NodeStore
+}  // namespace xrpl