validation: make CScriptCheck and prevector swap member functions noexcept

Reason:
A swap must not fail; when a class has a swap member function, it should be declared noexcept.
https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#c84-a-swap-function-must-not-fail

2 files changed, 4 insertions, 2 deletions

diff --git a/src/prevector.h b/src/prevector.h
index aa20efaaa7..830b31e315 100644
--- a/src/prevector.h
+++ b/src/prevector.h
@@ -458,7 +458,8 @@ public:
         return *item_ptr(size() - 1);
     }
 
-    void swap(prevector<N, T, Size, Diff>& other) {
+    void swap(prevector<N, T, Size, Diff>& other) noexcept
+    {
         std::swap(_union, other._union);
         std::swap(_size, other._size);
     }
diff --git a/src/validation.h b/src/validation.h
index e3ea8617e7..afc53bb445 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -328,7 +328,8 @@ public:
 
     bool operator()();
 
-    void swap(CScriptCheck &check) {
+    void swap(CScriptCheck& check) noexcept
+    {
         std::swap(ptxTo, check.ptxTo);
         std::swap(m_tx_out, check.m_tx_out);
         std::swap(nIn, check.nIn);