Add MPTIssue to STIssue (#5200)

Replace Issue in STIssue with Asset. STIssue with MPTIssue is only used in MPT tests.
Will be used in Vault and in transactions with STIssue fields once MPT is integrated into DEX.

include/xrpl/protocol/Asset.h

@@ -26,19 +26,28 @@
 
 namespace ripple {
 
+class Asset;
+
 template <typename TIss>
 concept ValidIssueType =
     std::is_same_v<TIss, Issue> || std::is_same_v<TIss, MPTIssue>;
 
+template <typename A>
+concept AssetType =
+    std::is_convertible_v<A, Asset> || std::is_convertible_v<A, Issue> ||
+    std::is_convertible_v<A, MPTIssue> || std::is_convertible_v<A, MPTID>;
+
 /* Asset is an abstraction of three different issue types: XRP, IOU, MPT.
  * For historical reasons, two issue types XRP and IOU are wrapped in Issue
  * type. Many functions and classes there were first written for Issue
  * have been rewritten for Asset.
  */
 class Asset
 {
-private:
+public:
     using value_type = std::variant<Issue, MPTIssue>;
+
+private:
     value_type issue_;
 
 public:
@@ -92,8 +101,8 @@ class Asset
     friend constexpr bool
     operator==(Asset const& lhs, Asset const& rhs);
 
-    friend constexpr bool
-    operator!=(Asset const& lhs, Asset const& rhs);
+    friend constexpr std::weak_ordering
+    operator<=>(Asset const& lhs, Asset const& rhs);
 
     friend constexpr bool
     operator==(Currency const& lhs, Asset const& rhs);
@@ -151,10 +160,22 @@ operator==(Asset const& lhs, Asset const& rhs)
         rhs.issue_);
 }
 
-constexpr bool
-operator!=(Asset const& lhs, Asset const& rhs)
+constexpr std::weak_ordering
+operator<=>(Asset const& lhs, Asset const& rhs)
 {
-    return !(lhs == rhs);
+    return std::visit(
+        []<ValidIssueType TLhs, ValidIssueType TRhs>(
+            TLhs const& lhs_, TRhs const& rhs_) {
+            if constexpr (std::is_same_v<TLhs, TRhs>)
+                return std::weak_ordering(lhs_ <=> rhs_);
+            else if constexpr (
+                std::is_same_v<TLhs, Issue> && std::is_same_v<TRhs, MPTIssue>)
+                return std::weak_ordering::greater;
+            else
+                return std::weak_ordering::less;
+        },
+        lhs.issue_,
+        rhs.issue_);
 }
 
 constexpr bool

include/xrpl/protocol/Indexes.h

@@ -274,7 +274,7 @@ nft_sells(uint256 const& id) noexcept;
 
 /** AMM entry */
 Keylet
-amm(Issue const& issue1, Issue const& issue2) noexcept;
+amm(Asset const& issue1, Asset const& issue2) noexcept;
 
 Keylet
 amm(uint256 const& amm) noexcept;

include/xrpl/protocol/Issue.h

@@ -58,6 +58,9 @@ class Issue
 
     bool
     native() const;
+
+    friend constexpr std::weak_ordering
+    operator<=>(Issue const& lhs, Issue const& rhs);
 };
 
 bool
@@ -95,7 +98,7 @@ operator==(Issue const& lhs, Issue const& rhs)
 
 /** Strict weak ordering. */
 /** @{ */
-[[nodiscard]] inline constexpr std::weak_ordering
+[[nodiscard]] constexpr std::weak_ordering
 operator<=>(Issue const& lhs, Issue const& rhs)
 {
     if (auto const c{lhs.currency <=> rhs.currency}; c != 0)

include/xrpl/protocol/MPTIssue.h

@@ -54,8 +54,8 @@ class MPTIssue
     friend constexpr bool
     operator==(MPTIssue const& lhs, MPTIssue const& rhs);
 
-    friend constexpr bool
-    operator!=(MPTIssue const& lhs, MPTIssue const& rhs);
+    friend constexpr std::weak_ordering
+    operator<=>(MPTIssue const& lhs, MPTIssue const& rhs);
 
     bool
     native() const
@@ -70,10 +70,10 @@ operator==(MPTIssue const& lhs, MPTIssue const& rhs)
     return lhs.mptID_ == rhs.mptID_;
 }
 
-constexpr bool
-operator!=(MPTIssue const& lhs, MPTIssue const& rhs)
+constexpr std::weak_ordering
+operator<=>(MPTIssue const& lhs, MPTIssue const& rhs)
 {
-    return !(lhs == rhs);
+    return lhs.mptID_ <=> rhs.mptID_;
 }
 
 /** MPT is a non-native token.

include/xrpl/protocol/SOTemplate.h

@@ -40,7 +40,7 @@ enum SOEStyle {
 };
 
 /** Amount fields that can support MPT */
-enum SOETxMPTAmount { soeMPTNone, soeMPTSupported, soeMPTNotSupported };
+enum SOETxMPTIssue { soeMPTNone, soeMPTSupported, soeMPTNotSupported };
 
 //------------------------------------------------------------------------------
 
@@ -50,7 +50,7 @@ class SOElement
     // Use std::reference_wrapper so SOElement can be stored in a std::vector.
     std::reference_wrapper<SField const> sField_;
     SOEStyle style_;
-    SOETxMPTAmount supportMpt_ = soeMPTNone;
+    SOETxMPTIssue supportMpt_ = soeMPTNone;
 
 private:
     void
@@ -72,10 +72,13 @@ class SOElement
     {
         init(fieldName);
     }
+
+    template <typename T>
+        requires(std::is_same_v<T, STAmount> || std::is_same_v<T, STIssue>)
     SOElement(
-        TypedField<STAmount> const& fieldName,
+        TypedField<T> const& fieldName,
         SOEStyle style,
-        SOETxMPTAmount supportMpt = soeMPTNotSupported)
+        SOETxMPTIssue supportMpt = soeMPTNotSupported)
         : sField_(fieldName), style_(style), supportMpt_(supportMpt)
     {
         init(fieldName);
@@ -93,7 +96,7 @@ class SOElement
         return style_;
     }
 
-    SOETxMPTAmount
+    SOETxMPTIssue
     supportMPT() const
     {
         return supportMpt_;

include/xrpl/protocol/STAmount.h

@@ -36,11 +36,6 @@
 
 namespace ripple {
 
-template <typename A>
-concept AssetType =
-    std::is_same_v<A, Asset> || std::is_convertible_v<A, Issue> ||
-    std::is_convertible_v<A, MPTIssue> || std::is_convertible_v<A, MPTID>;
-
 // Internal form:
 // 1: If amount is zero, then value is zero and offset is -100
 // 2: Otherwise:

include/xrpl/protocol/STIssue.h

@@ -21,7 +21,7 @@
 #define RIPPLE_PROTOCOL_STISSUE_H_INCLUDED
 
 #include <xrpl/basics/CountedObject.h>
-#include <xrpl/protocol/Issue.h>
+#include <xrpl/protocol/Asset.h>
 #include <xrpl/protocol/SField.h>
 #include <xrpl/protocol/STBase.h>
 #include <xrpl/protocol/Serializer.h>
@@ -31,31 +31,40 @@ namespace ripple {
 class STIssue final : public STBase, CountedObject<STIssue>
 {
 private:
-    Issue issue_{xrpIssue()};
+    Asset asset_{xrpIssue()};
 
 public:
-    using value_type = Issue;
+    using value_type = Asset;
 
     STIssue() = default;
 
     explicit STIssue(SerialIter& sit, SField const& name);
 
-    explicit STIssue(SField const& name, Issue const& issue);
+    template <AssetType A>
+    explicit STIssue(SField const& name, A const& issue);
 
     explicit STIssue(SField const& name);
 
-    Issue const&
-    issue() const;
+    template <ValidIssueType TIss>
+    TIss const&
+    get() const;
 
-    Issue const&
+    template <ValidIssueType TIss>
+    bool
+    holds() const;
+
+    value_type const&
     value() const noexcept;
 
     void
-    setIssue(Issue const& issue);
+    setIssue(Asset const& issue);
 
     SerializedTypeID
     getSType() const override;
 
+    std::string
+    getText() const override;
+
     Json::Value getJson(JsonOptions) const override;
 
     void
@@ -67,6 +76,18 @@ class STIssue final : public STBase, CountedObject<STIssue>
     bool
     isDefault() const override;
 
+    friend constexpr bool
+    operator==(STIssue const& lhs, STIssue const& rhs);
+
+    friend constexpr std::weak_ordering
+    operator<=>(STIssue const& lhs, STIssue const& rhs);
+
+    friend constexpr bool
+    operator==(STIssue const& lhs, Asset const& rhs);
+
+    friend constexpr std::weak_ordering
+    operator<=>(STIssue const& lhs, Asset const& rhs);
+
 private:
     STBase*
     copy(std::size_t n, void* buf) const override;
@@ -76,59 +97,72 @@ class STIssue final : public STBase, CountedObject<STIssue>
     friend class detail::STVar;
 };
 
+template <AssetType A>
+STIssue::STIssue(SField const& name, A const& asset)
+    : STBase{name}, asset_{asset}
+{
+    if (holds<Issue>() && !isConsistent(asset_.get<Issue>()))
+        Throw<std::runtime_error>(
+            "Invalid asset: currency and account native mismatch");
+}
+
 STIssue
 issueFromJson(SField const& name, Json::Value const& v);
 
-inline Issue const&
-STIssue::issue() const
+template <ValidIssueType TIss>
+bool
+STIssue::holds() const
+{
+    return asset_.holds<TIss>();
+}
+
+template <ValidIssueType TIss>
+TIss const&
+STIssue::get() const
 {
-    return issue_;
+    if (!holds<TIss>(asset_))
+        Throw<std::runtime_error>("Asset doesn't hold the requested issue");
+    return std::get<TIss>(asset_);
 }
 
-inline Issue const&
+inline STIssue::value_type const&
 STIssue::value() const noexcept
 {
-    return issue_;
+    return asset_;
 }
 
 inline void
-STIssue::setIssue(Issue const& issue)
+STIssue::setIssue(Asset const& asset)
 {
-    if (isXRP(issue_.currency) != isXRP(issue_.account))
+    if (holds<Issue>() && !isConsistent(asset_.get<Issue>()))
         Throw<std::runtime_error>(
-            "invalid issue: currency and account native mismatch");
+            "Invalid asset: currency and account native mismatch");
 
-    issue_ = issue;
+    asset_ = asset;
 }
 
-inline bool
+constexpr bool
 operator==(STIssue const& lhs, STIssue const& rhs)
 {
-    return lhs.issue() == rhs.issue();
-}
-
-inline bool
-operator!=(STIssue const& lhs, STIssue const& rhs)
-{
-    return !operator==(lhs, rhs);
+    return lhs.asset_ == rhs.asset_;
 }
 
-inline bool
-operator<(STIssue const& lhs, STIssue const& rhs)
+constexpr std::weak_ordering
+operator<=>(STIssue const& lhs, STIssue const& rhs)
 {
-    return lhs.issue() < rhs.issue();
+    return lhs.asset_ <=> rhs.asset_;
 }
 
-inline bool
-operator==(STIssue const& lhs, Issue const& rhs)
+constexpr bool
+operator==(STIssue const& lhs, Asset const& rhs)
 {
-    return lhs.issue() == rhs;
+    return lhs.asset_ == rhs;
 }
 
-inline bool
-operator<(STIssue const& lhs, Issue const& rhs)
+constexpr std::weak_ordering
+operator<=>(STIssue const& lhs, Asset const& rhs)
 {
-    return lhs.issue() < rhs;
+    return lhs.asset_ <=> rhs;
 }
 
 }  // namespace ripple

include/xrpl/protocol/STXChainBridge.h

@@ -170,7 +170,7 @@ STXChainBridge::lockingChainDoor() const
 inline Issue const&
 STXChainBridge::lockingChainIssue() const
 {
-    return lockingChainIssue_.value();
+    return lockingChainIssue_.value().get<Issue>();
 };
 
 inline AccountID const&
@@ -182,7 +182,7 @@ STXChainBridge::issuingChainDoor() const
 inline Issue const&
 STXChainBridge::issuingChainIssue() const
 {
-    return issuingChainIssue_.value();
+    return issuingChainIssue_.value().get<Issue>();
 };
 
 inline STXChainBridge::value_type const&

src/libxrpl/protocol/Indexes.cpp

@@ -18,6 +18,7 @@
 //==============================================================================
 
 #include <xrpl/beast/utility/instrumentation.h>
+#include <xrpl/protocol/Asset.h>
 #include <xrpl/protocol/Indexes.h>
 #include <xrpl/protocol/LedgerFormats.h>
 #include <xrpl/protocol/SField.h>
@@ -417,9 +418,10 @@ nft_sells(uint256 const& id) noexcept
 }
 
 Keylet
-amm(Issue const& issue1, Issue const& issue2) noexcept
+amm(Asset const& issue1, Asset const& issue2) noexcept
 {
-    auto const& [minI, maxI] = std::minmax(issue1, issue2);
+    auto const& [minI, maxI] =
+        std::minmax(issue1.get<Issue>(), issue2.get<Issue>());
     return amm(indexHash(
         LedgerNameSpace::AMM,
         minI.account,