Refactor get<T>(). Minor refactoring to be consistent with develop.

include/xrpl/protocol/Feature.h

@@ -80,7 +80,7 @@ namespace detail {
 // Feature.cpp. Because it's only used to reserve storage, and determine how
 // large to make the FeatureBitset, it MAY be larger. It MUST NOT be less than
 // the actual number of amendments. A LogicError on startup will verify this.
-static constexpr std::size_t numFeatures = 78;
+static constexpr std::size_t numFeatures = 79;
 
 /** Amendments that this server supports and the default voting behavior.
    Whether they are enabled depends on the Rules defined in the validated
@@ -370,6 +370,7 @@ extern uint256 const featureNFTokenMintOffer;
 extern uint256 const fixReducedOffersV2;
 extern uint256 const fixEnforceNFTokenTrustline;
 extern uint256 const fixInnerObjTemplate2;
+extern uint256 const featureInvariantsV1_1;
 extern uint256 const featureMPTokensV1;
 
 }  // namespace ripple

include/xrpl/protocol/Indexes.h

@@ -29,6 +29,7 @@
 #include <xrpl/protocol/STXChainBridge.h>
 #include <xrpl/protocol/Serializer.h>
 #include <xrpl/protocol/UintTypes.h>
+#include <xrpl/protocol/jss.h>
 #include <cstdint>
 
 namespace ripple {
@@ -336,6 +337,26 @@ getTicketIndex(AccountID const& account, std::uint32_t uSequence);
 uint256
 getTicketIndex(AccountID const& account, SeqProxy ticketSeq);
 
+template <class... keyletParams>
+struct keyletDesc
+{
+    std::function<Keylet(keyletParams...)> function;
+    Json::StaticString expectedLEName;
+    bool includeInTests;
+};
+
+// This list should include all of the keylet functions that take a single
+// AccountID parameter.
+std::array<keyletDesc<AccountID const&>, 6> const directAccountKeylets{
+    {{&keylet::account, jss::AccountRoot, false},
+     {&keylet::ownerDir, jss::DirectoryNode, true},
+     {&keylet::signers, jss::SignerList, true},
+     // It's normally impossible to create an item at nftpage_min, but
+     // test it anyway, since the invariant checks for it.
+     {&keylet::nftpage_min, jss::NFTokenPage, true},
+     {&keylet::nftpage_max, jss::NFTokenPage, true},
+     {&keylet::did, jss::DID, true}}};
+
 uint192
 getMptID(AccountID const& account, std::uint32_t sequence);
 

include/xrpl/protocol/STEitherAmount.h

@@ -162,10 +162,7 @@ get(auto&& amount)
         if constexpr (std::is_lvalue_reference_v<decltype(amount)>)
             return amount.template get<T>();
         else
-        {
-            T a = amount.template get<T>();
-            return a;
-        }
+            return std::remove_reference_t<T>(amount.template get<T>());
     }
     else if constexpr (std::is_same_v<TAmnt, std::optional<STEitherAmount>>)
     {
@@ -179,10 +176,8 @@ get(auto&& amount)
         if constexpr (std::is_lvalue_reference_v<decltype(amount)>)
             return amount.operator STEitherAmount().template get<T>();
         else
-        {
-            T a = amount.operator STEitherAmount().template get<T>();
-            return a;
-        }
+            return std::remove_reference_t<T>(
+                amount.operator STEitherAmount().template get<T>());
     }
     else
     {

include/xrpl/protocol/TxMeta.h

@@ -108,7 +108,7 @@ class TxMeta
     }
 
     void
-    setDeliveredAmount(STAmount const& delivered)
+    setDeliveredAmount(STEitherAmount const& delivered)
     {
         mDelivered = delivered;
     }

include/xrpl/protocol/UintTypes.h

@@ -46,12 +46,6 @@ class NodeIDTag
     explicit NodeIDTag() = default;
 };
 
-class MPTTag
-{
-public:
-    explicit MPTTag() = default;
-};
-
 }  // namespace detail
 
 /** Directory is an index into the directory of offer books.

src/libxrpl/protocol/Feature.cpp

@@ -497,6 +497,9 @@ REGISTER_FEATURE(NFTokenMintOffer,              Supported::yes, VoteBehavior::De
 REGISTER_FIX    (fixReducedOffersV2,            Supported::yes, VoteBehavior::DefaultNo);
 REGISTER_FIX    (fixEnforceNFTokenTrustline,    Supported::yes, VoteBehavior::DefaultNo);
 REGISTER_FIX    (fixInnerObjTemplate2,          Supported::yes, VoteBehavior::DefaultNo);
+// InvariantsV1_1 will be changes to Supported::yes when all the
+// invariants expected to be included under it are complete.
+REGISTER_FEATURE(InvariantsV1_1,                Supported::no, VoteBehavior::DefaultNo);
 REGISTER_FEATURE(MPTokensV1,                    Supported::yes, VoteBehavior::DefaultNo);
 
 // The following amendments are obsolete, but must remain supported

src/libxrpl/protocol/TxMeta.cpp

@@ -42,8 +42,7 @@ TxMeta::TxMeta(
     mNodes = *dynamic_cast<STArray*>(&obj.getField(sfAffectedNodes));
 
     if (obj.isFieldPresent(sfDeliveredAmount))
-        setDeliveredAmount(
-            get<STAmount>(obj.getFieldAmount(sfDeliveredAmount)));
+        setDeliveredAmount(obj.getFieldAmount(sfDeliveredAmount));
 }
 
 TxMeta::TxMeta(uint256 const& txid, std::uint32_t ledger, STObject const& obj)
@@ -61,8 +60,7 @@ TxMeta::TxMeta(uint256 const& txid, std::uint32_t ledger, STObject const& obj)
         mNodes = *affectedNodes;
 
     if (obj.isFieldPresent(sfDeliveredAmount))
-        setDeliveredAmount(
-            get<STAmount>(obj.getFieldAmount(sfDeliveredAmount)));
+        setDeliveredAmount(obj.getFieldAmount(sfDeliveredAmount));
 }
 
 TxMeta::TxMeta(uint256 const& txid, std::uint32_t ledger, Blob const& vec)

src/xrpld/app/misc/FeeVoteImpl.cpp

@@ -277,9 +277,9 @@ FeeVoteImpl::doVoting(
     }
 
     // choose our positions
-    // TODO: Use structured binding once LLVM issue
-    // https://github.com/llvm/llvm-project/issues/48582
-    // is fixed.
+    // 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 baseFee = baseFeeVote.getVotes();
     auto const baseReserve = baseReserveVote.getVotes();
     auto const incReserve = incReserveVote.getVotes();

src/xrpld/app/paths/Credit.cpp

@@ -31,7 +31,7 @@ creditLimit(
     AccountID const& issuer,
     Currency const& currency)
 {
-    STAmount result(Issue{currency, account});
+    STAmount result({currency, account});
 
     auto sleRippleState = view.read(keylet::line(account, issuer, currency));
 
@@ -64,7 +64,7 @@ creditBalance(
     AccountID const& issuer,
     Currency const& currency)
 {
-    STAmount result(Issue{currency, account});
+    STAmount result({currency, account});
 
     auto sleRippleState = view.read(keylet::line(account, issuer, currency));
 

src/xrpld/app/paths/PathRequest.cpp

@@ -562,7 +562,7 @@ PathRequest::findPaths(
         }();
 
         STAmount saMaxAmount = saSendMax.value_or(
-            STAmount(Issue{issue.currency, sourceAccount}, 1u, 0, true));
+            STAmount({issue.currency, sourceAccount}, 1u, 0, true));
 
         JLOG(m_journal.debug())
             << iIdentifier << " Paths found, calling rippleCalc";

src/xrpld/app/paths/Pathfinder.cpp

@@ -176,10 +176,9 @@ Pathfinder::Pathfinder(
     , mSrcCurrency(uSrcCurrency)
     , mSrcIssuer(uSrcIssuer)
     , mSrcAmount(srcAmount.value_or(STAmount(
-          Issue{
-              uSrcCurrency,
-              uSrcIssuer.value_or(
-                  isXRP(uSrcCurrency) ? xrpAccount() : uSrcAccount)},
+          {uSrcCurrency,
+           uSrcIssuer.value_or(
+               isXRP(uSrcCurrency) ? xrpAccount() : uSrcAccount)},
           1u,
           0,
           true)))

src/xrpld/app/tx/detail/InvariantCheck.cpp

@@ -365,6 +365,91 @@ AccountRootsNotDeleted::finalize(
 
 //------------------------------------------------------------------------------
 
+void
+AccountRootsDeletedClean::visitEntry(
+    bool isDelete,
+    std::shared_ptr<SLE const> const& before,
+    std::shared_ptr<SLE const> const&)
+{
+    if (isDelete && before && before->getType() == ltACCOUNT_ROOT)
+        accountsDeleted_.emplace_back(before);
+}
+
+bool
+AccountRootsDeletedClean::finalize(
+    STTx const& tx,
+    TER const result,
+    XRPAmount const,
+    ReadView const& view,
+    beast::Journal const& j)
+{
+    // Always check for objects in the ledger, but to prevent differing
+    // transaction processing results, however unlikely, only fail if the
+    // feature is enabled. Enabled, or not, though, a fatal-level message will
+    // be logged
+    bool const enforce = view.rules().enabled(featureInvariantsV1_1);
+
+    auto const objectExists = [&view, enforce, &j](auto const& keylet) {
+        if (auto const sle = view.read(keylet))
+        {
+            // Finding the object is bad
+            auto const typeName = [&sle]() {
+                auto item =
+                    LedgerFormats::getInstance().findByType(sle->getType());
+
+                if (item != nullptr)
+                    return item->getName();
+                return std::to_string(sle->getType());
+            }();
+
+            JLOG(j.fatal())
+                << "Invariant failed: account deletion left behind a "
+                << typeName << " object";
+            (void)enforce;
+            assert(enforce);
+            return true;
+        }
+        return false;
+    };
+
+    for (auto const& accountSLE : accountsDeleted_)
+    {
+        auto const accountID = accountSLE->getAccountID(sfAccount);
+        // Simple types
+        for (auto const& [keyletfunc, _, __] : directAccountKeylets)
+        {
+            if (objectExists(std::invoke(keyletfunc, accountID)) && enforce)
+                return false;
+        }
+
+        {
+            // NFT pages. ntfpage_min and nftpage_max were already explicitly
+            // checked above as entries in directAccountKeylets. This uses
+            // view.succ() to check for any NFT pages in between the two
+            // endpoints.
+            Keylet const first = keylet::nftpage_min(accountID);
+            Keylet const last = keylet::nftpage_max(accountID);
+
+            std::optional<uint256> key = view.succ(first.key, last.key.next());
+
+            // current page
+            if (key && objectExists(Keylet{ltNFTOKEN_PAGE, *key}) && enforce)
+                return false;
+        }
+
+        // Keys directly stored in the AccountRoot object
+        if (auto const ammKey = accountSLE->at(~sfAMMID))
+        {
+            if (objectExists(keylet::amm(*ammKey)) && enforce)
+                return false;
+        }
+    }
+
+    return true;
+}
+
+//------------------------------------------------------------------------------
+
 void
 LedgerEntryTypesMatch::visitEntry(
     bool,

src/xrpld/app/tx/detail/InvariantCheck.h

@@ -164,6 +164,36 @@ class AccountRootsNotDeleted
         beast::Journal const&);
 };
 
+/**
+ * @brief Invariant: a deleted account must not have any objects left
+ *
+ * We iterate all deleted account roots, and ensure that there are no
+ * objects left that are directly accessible with that account's ID.
+ *
+ * There should only be one deleted account, but that's checked by
+ * AccountRootsNotDeleted. This invariant will handle multiple deleted account
+ * roots without a problem.
+ */
+class AccountRootsDeletedClean
+{
+    std::vector<std::shared_ptr<SLE const>> accountsDeleted_;
+
+public:
+    void
+    visitEntry(
+        bool,
+        std::shared_ptr<SLE const> const&,
+        std::shared_ptr<SLE const> const&);
+
+    bool
+    finalize(
+        STTx const&,
+        TER const,
+        XRPAmount const,
+        ReadView const&,
+        beast::Journal const&);
+};
+
 /**
  * @brief Invariant: An account XRP balance must be in XRP and take a value
  *                   between 0 and INITIAL_XRP drops, inclusive.
@@ -448,6 +478,7 @@ class ValidMPTIssuance
 using InvariantChecks = std::tuple<
     TransactionFeeCheck,
     AccountRootsNotDeleted,
+    AccountRootsDeletedClean,
     LedgerEntryTypesMatch,
     XRPBalanceChecks,
     XRPNotCreated,

src/xrpld/app/tx/detail/NFTokenAcceptOffer.cpp

@@ -104,7 +104,8 @@ NFTokenAcceptOffer::preclaim(PreclaimContext const& ctx)
             return tecNFTOKEN_BUY_SELL_MISMATCH;
 
         // The two offers being brokered must be for the same asset:
-        if (!(*bo)[sfAmount].sameIssue((*so)[sfAmount]))
+        if (get<STAmount>((*bo)[sfAmount]).issue() !=
+            get<STAmount>((*so)[sfAmount]).issue())
             return tecNFTOKEN_BUY_SELL_MISMATCH;
 
         // The two offers may not form a loop.  A broker may not sell the