Address AI review feedback

- Mostly just clarifying comments and reorganizing functions.

include/xrpl/basics/Number.h

@@ -136,6 +136,10 @@ struct MantissaRange final
         Large320,
         // If Large330 is ever the only remaining "Large*" entry, it can be renamed to just "Large".
         Large330,
+        // Large is a de-facto alias for "the latest", and is only here for backward compatibility
+        // in the extremely unlikely case that a downstream project made use of it. Note that
+        // because the behavior changed, this may still be a breaking change.
+        Large = Large330,
     };
 
     // This entire enum can be removed when the last relevant amendment is retired
@@ -146,6 +150,10 @@ struct MantissaRange final
         Enabled320 = 1,
         // If we ever get to the point that there's only one entry, remove the entire enum
         Enabled330 = 2,
+        // Enabled is a de-facto alias for "the latest", and is only here for backward compatibility
+        // in the extremely unlikely case that a downstream project made use of it. Note that
+        // because the behavior changed, this may still be a breaking change.
+        Enabled = Enabled330,
     };
 
     explicit constexpr MantissaRange(MantissaScale sc) : scale(sc)
@@ -158,11 +166,25 @@ struct MantissaRange final
     rep const max{(min * 10) - 1};
     CuspRoundingFix const cuspRoundingFix{isCuspFixEnabled(scale)};
 
-    static constexpr MantissaRange const&
-    getMantissaRange(MantissaScale scale);
+    static constexpr std::set<MantissaScale> const&
+    getAllScales()
+    {
+        static std::set<MantissaRange::MantissaScale> const kScales = {
+            MantissaRange::MantissaScale::Small,
+            MantissaRange::MantissaScale::LargeLegacy,
+            MantissaRange::MantissaScale::Large320,
+            MantissaRange::MantissaScale::Large330,
+        };
+        return kScales;
+    }
 
-    static std::set<MantissaScale> const&
-    getAllScales();
+    class Get
+    {
+        static constexpr MantissaRange const&
+        mantissaRange(MantissaScale scale);
+
+        friend Number;
+    };
 
 private:
     static constexpr int

src/libxrpl/basics/Number.cpp

@@ -30,7 +30,7 @@ namespace xrpl {
 
 thread_local Number::RoundingMode Number::mode = Number::RoundingMode::ToNearest;
 thread_local std::reference_wrapper<MantissaRange const> Number::kRange =
-    MantissaRange::getMantissaRange(MantissaRange::MantissaScale::Large330);
+    MantissaRange::Get::mantissaRange(MantissaRange::MantissaScale::Large330);
 
 std::string
 to_string(MantissaRange::MantissaScale const& scale)
@@ -68,20 +68,8 @@ to_string(Number::RoundingMode const& round)
     }
 }
 
-std::set<MantissaRange::MantissaScale> const&
-MantissaRange::getAllScales()
-{
-    static std::set<MantissaRange::MantissaScale> const kScales = {
-        MantissaRange::MantissaScale::Small,
-        MantissaRange::MantissaScale::LargeLegacy,
-        MantissaRange::MantissaScale::Large320,
-        MantissaRange::MantissaScale::Large330,
-    };
-    return kScales;
-}
-
 constexpr MantissaRange const&
-MantissaRange::getMantissaRange(MantissaScale scale)
+MantissaRange::Get::mantissaRange(MantissaScale scale)
 {
     static constexpr MantissaRange kSmall{MantissaScale::Small};
     static constexpr MantissaRange kLegacy{MantissaScale::LargeLegacy};
@@ -164,7 +152,7 @@ Number::setMantissaScale(MantissaRange::MantissaScale scale)
 {
     if (!MantissaRange::getAllScales().contains(scale))
         logicError("Unknown mantissa scale");
-    kRange = MantissaRange::getMantissaRange(scale);
+    kRange = MantissaRange::Get::mantissaRange(scale);
 }
 
 // Optimization equivalent to:

src/libxrpl/protocol/Rules.cpp

@@ -41,23 +41,24 @@ setCurrentTransactionRules(std::optional<Rules> r)
 
     // Declare the range this way to keep clang-tidy from complaining
     auto const range = [&r]() {
-        // If any new conditions with new amendments are added to "enableVaultNumbers", those
+        // If any new conditions with new amendments are added to "enableLargeNumbers", those
         // amendments must also be added to useRulesGuards.
-        bool const enableVaultNumbers =
+        bool const enableLargeNumbers =
             !r || (r->enabled(featureSingleAssetVault) || r->enabled(featureLendingProtocol));
+        // If enableLargeNumbers is true, then useRulesGuard must also return true.
+        // However, the reverse is not true. Other amendments can cause the rules guard to be used,
+        // even though large numbers are _not_ used.
         XRPL_ASSERT(
-            !r || !enableVaultNumbers || useRulesGuards(*r),
+            !r || !enableLargeNumbers || useRulesGuards(*r),
             "setCurrentTransactionRules : rule decisions match");
-        bool const enableCuspRounding320 = !r || r->enabled(fixCleanup3_2_0);
-        bool const enableCuspRounding330 = !r || r->enabled(fixCleanup3_3_0);
 
-        if (enableVaultNumbers)
+        if (enableLargeNumbers)
         {
-            if (enableCuspRounding330)
+            if (!r || r->enabled(fixCleanup3_3_0))
             {
                 return MantissaRange::MantissaScale::Large330;
             }
-            if (enableCuspRounding320)
+            if (r->enabled(fixCleanup3_2_0))
             {
                 return MantissaRange::MantissaScale::Large320;
             }
@@ -74,7 +75,7 @@ bool
 useRulesGuards(Rules const& rules)
 {
     // The list of amendments used here - to decide whether to create a RulesGuard - must be a
-    // superset of the list used to determine "enableVaultNumbers" in setCurrentTransactionRules.
+    // superset of the list used to determine "enableLargeNumbers" in setCurrentTransactionRules.
     // Additional amendments can be added if desired.
     //
     // As soon as any one of these amendments is retired, this whole function can be removed, along
@@ -92,7 +93,8 @@ createGuards(
 {
     if (useRulesGuards(rules))
     {
-        // raii classes for the current ledger rules.
+        // raii classes for the current ledger rules. If the rules are set, the MantissaRange will
+        // be updated, too.
         rulesGuard.emplace(rules);
     }
     else