consensus, refactor: Avoid CScriptCheck::swap in CheckInputScripts

Author: hebasto

src/validation.cpp

@@ -1815,8 +1815,7 @@ bool CheckInputScripts(const CTransaction& tx, TxValidationState& state,
         // Verify signature
         CScriptCheck check(txdata.m_spent_outputs[i], tx, i, flags, cacheSigStore, &txdata);
         if (pvChecks) {
-            pvChecks->push_back(CScriptCheck());
-            check.swap(pvChecks->back());
+            pvChecks->emplace_back(std::move(check));
         } else if (!check()) {
             if (flags & STANDARD_NOT_MANDATORY_VERIFY_FLAGS) {
                 // Check whether the failure was caused by a

src/validation.h

@@ -322,6 +322,11 @@ class CScriptCheck
     CScriptCheck(const CTxOut& outIn, const CTransaction& txToIn, unsigned int nInIn, unsigned int nFlagsIn, bool cacheIn, PrecomputedTransactionData* txdataIn) :
         m_tx_out(outIn), ptxTo(&txToIn), nIn(nInIn), nFlags(nFlagsIn), cacheStore(cacheIn), error(SCRIPT_ERR_UNKNOWN_ERROR), txdata(txdataIn) { }
 
+    CScriptCheck(const CScriptCheck&) = delete;
+    CScriptCheck& operator=(const CScriptCheck&) = delete;
+    CScriptCheck(CScriptCheck&&) = default;
+    CScriptCheck& operator=(CScriptCheck&&) = default;
+
     bool operator()();
 
     void swap(CScriptCheck& check) noexcept