Step 1: Convert Number to use 128-bit numbers internally

- Update the conversion points between Number and *Amount & STNumber.
- Tests probably don't pass.

include/xrpl/protocol/AmountConversions.h

@@ -122,7 +122,7 @@ toAmount(
     {
         if (isXRP(issue))
             return STAmount(issue, static_cast<std::int64_t>(n));
-        return STAmount(issue, n.mantissa(), n.exponent());
+        return STAmount(issue, n);
     }
     else
     {

include/xrpl/protocol/Asset.h

@@ -84,6 +84,12 @@ public:
         return holds<Issue>() && get<Issue>().native();
     }
 
+    bool
+    integral() const
+    {
+        return !holds<Issue>() || get<Issue>().native();
+    }
+
     friend constexpr bool
     operator==(Asset const& lhs, Asset const& rhs);
 

include/xrpl/protocol/IOUAmount.h

@@ -26,8 +26,10 @@ class IOUAmount : private boost::totally_ordered<IOUAmount>,
                   private boost::additive<IOUAmount>
 {
 private:
-    std::int64_t mantissa_;
-    int exponent_;
+    using mantissa_type = std::int64_t;
+    using exponent_type = int;
+    mantissa_type mantissa_;
+    exponent_type exponent_;
 
     /** Adjusts the mantissa and exponent to the proper range.
 
@@ -38,11 +40,19 @@ private:
     void
     normalize();
 
+    IOUAmount(std::pair<mantissa_type, exponent_type> parts)
+        : IOUAmount(parts.first, parts.second)
+    {
+    }
+
+    static std::pair<mantissa_type, exponent_type>
+    scaleNumber(Number const& number);
+
 public:
     IOUAmount() = default;
     explicit IOUAmount(Number const& other);
     IOUAmount(beast::Zero);
-    IOUAmount(std::int64_t mantissa, int exponent);
+    IOUAmount(mantissa_type mantissa, exponent_type exponent);
 
     IOUAmount& operator=(beast::Zero);
 
@@ -71,10 +81,10 @@ public:
     int
     signum() const noexcept;
 
-    int
+    exponent_type
     exponent() const noexcept;
 
-    std::int64_t
+    mantissa_type
     mantissa() const noexcept;
 
     static IOUAmount
@@ -92,7 +102,7 @@ inline IOUAmount::IOUAmount(beast::Zero)
     *this = beast::zero;
 }
 
-inline IOUAmount::IOUAmount(std::int64_t mantissa, int exponent)
+inline IOUAmount::IOUAmount(mantissa_type mantissa, exponent_type exponent)
     : mantissa_(mantissa), exponent_(exponent)
 {
     normalize();
@@ -149,13 +159,13 @@ IOUAmount::signum() const noexcept
     return (mantissa_ < 0) ? -1 : (mantissa_ ? 1 : 0);
 }
 
-inline int
+inline IOUAmount::exponent_type
 IOUAmount::exponent() const noexcept
 {
     return exponent_;
 }
 
-inline std::int64_t
+inline IOUAmount::mantissa_type
 IOUAmount::mantissa() const noexcept
 {
     return mantissa_;

include/xrpl/protocol/Issue.h

@@ -37,6 +37,9 @@ public:
     bool
     native() const;
 
+    bool
+    integral() const;
+
     friend constexpr std::weak_ordering
     operator<=>(Issue const& lhs, Issue const& rhs);
 };

include/xrpl/protocol/MPTIssue.h

@@ -46,6 +46,12 @@ public:
     {
         return false;
     }
+
+    bool
+    integral() const
+    {
+        return true;
+    }
 };
 
 constexpr bool

include/xrpl/protocol/STAmount.h

@@ -47,9 +47,11 @@ public:
     static int const cMaxOffset = 80;
 
     // Maximum native value supported by the code
-    static std::uint64_t const cMinValue = 1000000000000000ull;
-    static std::uint64_t const cMaxValue = 9999999999999999ull;
-    static std::uint64_t const cMaxNative = 9000000000000000000ull;
+    constexpr static std::uint64_t cMinValue = 1'000'000'000'000'000ull;
+    static_assert(isPowerOfTen(cMinValue));
+    constexpr static std::uint64_t cMaxValue = cMinValue * 10 - 1;
+    static_assert(cMaxValue == 9'999'999'999'999'999ull);
+    static std::uint64_t const cMaxNative = 9'000'000'000'000'000'000ull;
 
     // Max native value on network.
     static std::uint64_t const cMaxNativeN = 100000000000000000ull;
@@ -136,7 +138,7 @@ public:
 
     template <AssetType A>
     STAmount(A const& asset, Number const& number)
-        : STAmount(asset, number.mantissa(), number.exponent())
+        : STAmount(asset, scaleNumber(asset, number))
     {
     }
 
@@ -155,6 +157,9 @@ public:
     int
     exponent() const noexcept;
 
+    bool
+    integral() const noexcept;
+
     bool
     native() const noexcept;
 
@@ -277,6 +282,22 @@ public:
     mpt() const;
 
 private:
+    template <AssetType A>
+    STAmount(
+        A const& asset,
+        std::tuple<mantissa_type, exponent_type, bool> parts)
+        : STAmount(
+              asset,
+              std::get<mantissa_type>(parts),
+              std::get<exponent_type>(parts),
+              std::get<bool>(parts))
+    {
+    }
+
+    template <AssetType A>
+    static std::tuple<mantissa_type, exponent_type, bool>
+    scaleNumber(A const& asset, Number const& number);
+
     static std::unique_ptr<STAmount>
     construct(SerialIter&, SField const& name);
 
@@ -435,6 +456,12 @@ STAmount::exponent() const noexcept
     return mOffset;
 }
 
+inline bool
+STAmount::integral() const noexcept
+{
+    return mAsset.integral();
+}
+
 inline bool
 STAmount::native() const noexcept
 {
@@ -531,12 +558,29 @@ STAmount::operator=(XRPAmount const& amount)
     return *this;
 }
 
+template <AssetType A>
+inline std::tuple<STAmount::mantissa_type, STAmount::exponent_type, bool>
+STAmount::scaleNumber(A const& asset, Number const& number)
+{
+    bool const negative = number.mantissa() < 0;
+    if (asset.integral())
+    {
+        return std::make_tuple(std::int64_t(number), 0, negative);
+    }
+    else
+    {
+        Number const working{negative ? -number : number};
+        auto const [mantissa, exponent] =
+            working.normalizeToRange(cMinValue, cMaxValue);
+
+        return std::make_tuple(mantissa, exponent, negative);
+    }
+}
+
 inline STAmount&
 STAmount::operator=(Number const& number)
 {
-    mIsNegative = number.mantissa() < 0;
-    mValue = mIsNegative ? -number.mantissa() : number.mantissa();
-    mOffset = number.exponent();
+    std::tie(mValue, mOffset, mIsNegative) = scaleNumber(mAsset, number);
     canonicalize();
     return *this;
 }
@@ -553,7 +597,7 @@ STAmount::clear()
 {
     // The -100 is used to allow 0 to sort less than a small positive values
     // which have a negative exponent.
-    mOffset = native() ? 0 : -100;
+    mOffset = integral() ? 0 : -100;
     mValue = 0;
     mIsNegative = false;
 }

include/xrpl/protocol/STObject.h

@@ -482,6 +482,8 @@ public:
     value_type
     operator*() const;
 
+    /// Do not use operator->() unless the field is required, or you've checked
+    /// that it's set.
     T const*
     operator->() const;
 
@@ -718,6 +720,8 @@ STObject::Proxy<T>::operator*() const -> value_type
     return this->value();
 }
 
+/// Do not use operator->() unless the field is required, or you've checked that
+/// it's set.
 template <class T>
 T const*
 STObject::Proxy<T>::operator->() const

include/xrpl/protocol/SystemParameters.h

@@ -23,6 +23,7 @@ systemName()
 
 /** Number of drops in the genesis account. */
 constexpr XRPAmount INITIAL_XRP{100'000'000'000 * DROPS_PER_XRP};
+static_assert(INITIAL_XRP.drops() == 100'000'000'000'000'000);
 
 /** Returns true if the amount does not exceed the initial XRP in existence. */
 inline bool

include/xrpl/protocol/detail/ledger_entries.macro

@@ -479,10 +479,10 @@ LEDGER_ENTRY(ltVAULT, 0x0084, Vault, vault, ({
     {sfAccount,              soeREQUIRED},
     {sfData,                 soeOPTIONAL},
     {sfAsset,                soeREQUIRED},
-    {sfAssetsTotal,          soeREQUIRED},
-    {sfAssetsAvailable,      soeREQUIRED},
+    {sfAssetsTotal,          soeDEFAULT},
+    {sfAssetsAvailable,      soeDEFAULT},
     {sfAssetsMaximum,        soeDEFAULT},
-    {sfLossUnrealized,       soeREQUIRED},
+    {sfLossUnrealized,       soeDEFAULT},
     {sfShareMPTID,           soeREQUIRED},
     {sfWithdrawalPolicy,     soeREQUIRED},
     {sfScale,                soeDEFAULT},