Fix pair::swap(const pair&) and tuple::swap(const tuple&) errors …

…with `__declspec(dllexport)` (#3045)
microsoft · Aug 22, 2022 · febb643 · febb643
1 parent 2a1b881
commit febb643
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Showing 3 changed files with 8 additions and 0 deletions.
diff --git a/stl/inc/tuple b/stl/inc/tuple
@@ -582,6 +582,7 @@ public:
     }
 
 #if _HAS_CXX23
+    template <int = 0> // see GH-3013
     constexpr void swap(const tuple& _Right) const
         noexcept(conjunction_v<is_nothrow_swappable<const _This>, is_nothrow_swappable<const _Rest>...>) {
         _Swap_adl(_Myfirst._Val, _Right._Myfirst._Val);

diff --git a/stl/inc/utility b/stl/inc/utility
@@ -329,6 +329,7 @@ struct pair { // store a pair of values
     }
 
 #if _HAS_CXX23
+    template <int = 0> // see GH-3013
     constexpr void swap(const pair& _Right) const
         noexcept(is_nothrow_swappable_v<const _Ty1>&& is_nothrow_swappable_v<const _Ty2>) {
         if (this != _STD addressof(_Right)) {

diff --git a/tests/std/tests/GH_001638_dllexport_derived_classes/test.compile.pass.cpp b/tests/std/tests/GH_001638_dllexport_derived_classes/test.compile.pass.cpp
@@ -9,8 +9,10 @@
 #include <queue>
 #include <set>
 #include <stack>
+#include <tuple>
 #include <unordered_map>
 #include <unordered_set>
+#include <utility>
 #include <vector>
 
 #if _HAS_CXX20
@@ -50,3 +52,7 @@ struct __declspec(dllexport) ExportedStack : stack<int> {};
 struct __declspec(dllexport) ExportedSpan : span<int> {};
 struct __declspec(dllexport) ExportedSpanThree : span<int, 3> {};
 #endif // _HAS_CXX20
+
+// Test GH-3013 "<utility>: pair::swap(const pair&) interacts badly with __declspec(dllexport)"
+struct __declspec(dllexport) ExportedPair : pair<int, int> {};
+struct __declspec(dllexport) ExportedTuple : tuple<int, int, int> {};