Bugfixes for `<any>` (#3965)

Co-authored-by: Stephan T. Lavavej <stl@microsoft.com>

stl/inc/any

@@ -78,17 +78,17 @@ struct _Any_small_RTTI { // Hand-rolled vtable for nontrivial types that can be
 
     template <class _Ty>
     static void __CLRCALL_PURE_OR_CDECL _Destroy_impl(void* const _Target) noexcept {
-        _Destroy_in_place(*static_cast<_Ty*>(_Target));
+        _STD _Destroy_in_place(*static_cast<_Ty*>(_Target));
     }
 
     template <class _Ty>
     static void __CLRCALL_PURE_OR_CDECL _Copy_impl(void* const _Target, const void* const _Source) {
-        _Construct_in_place(*static_cast<_Ty*>(_Target), *static_cast<const _Ty*>(_Source));
+        _STD _Construct_in_place(*static_cast<_Ty*>(_Target), *static_cast<const _Ty*>(_Source));
     }
 
     template <class _Ty>
     static void __CLRCALL_PURE_OR_CDECL _Move_impl(void* const _Target, void* const _Source) noexcept {
-        _Construct_in_place(*static_cast<_Ty*>(_Target), _STD move(*static_cast<_Ty*>(_Source)));
+        _STD _Construct_in_place(*static_cast<_Ty*>(_Target), _STD move(*static_cast<_Ty*>(_Source)));
     }
 
     _Destroy_fn* _Destroy;
@@ -163,13 +163,12 @@ public:
 
     // Assignment [any.assign]
     any& operator=(const any& _That) {
-        *this = any{_That};
+        _Assign(_That);
         return *this;
     }
 
     any& operator=(any&& _That) noexcept {
-        reset();
-        _Move_from(_That);
+        _Assign(_STD move(_That));
         return *this;
     }
 
@@ -178,7 +177,7 @@ public:
                                     int> = 0>
     any& operator=(_ValueType&& _Value) {
         // replace contained value with an object of type decay_t<_ValueType> initialized from _Value
-        *this = any{_STD forward<_ValueType>(_Value)};
+        _Assign(_STD forward<_ValueType>(_Value));
         return *this;
     }
 
@@ -290,19 +289,24 @@ private:
         }
     }
 
+    void _Assign(any _That) noexcept { // intentionally pass by value
+        reset();
+        _Move_from(_That);
+    }
+
     template <class _Decayed, class... _Types>
     _Decayed& _Emplace(_Types&&... _Args) { // emplace construct _Decayed
         if constexpr (_Any_is_trivial<_Decayed>) {
             // using the _Trivial representation
             auto& _Obj = reinterpret_cast<_Decayed&>(_Storage._TrivialData);
-            _Construct_in_place(_Obj, _STD forward<_Types>(_Args)...);
+            _STD _Construct_in_place(_Obj, _STD forward<_Types>(_Args)...);
             _Storage._TypeData =
                 reinterpret_cast<uintptr_t>(&typeid(_Decayed)) | static_cast<uintptr_t>(_Any_representation::_Trivial);
             return _Obj;
         } else if constexpr (_Any_is_small<_Decayed>) {
             // using the _Small representation
             auto& _Obj = reinterpret_cast<_Decayed&>(_Storage._SmallStorage._Data);
-            _Construct_in_place(_Obj, _STD forward<_Types>(_Args)...);
+            _STD _Construct_in_place(_Obj, _STD forward<_Types>(_Args)...);
             _Storage._SmallStorage._RTTI = &_Any_small_RTTI_obj<_Decayed>;
             _Storage._TypeData =
                 reinterpret_cast<uintptr_t>(&typeid(_Decayed)) | static_cast<uintptr_t>(_Any_representation::_Small);

tests/std/tests/P0220R1_any/test.cpp

@@ -2570,21 +2570,41 @@ namespace msvc {
                     // empty
                     any a;
                     a = std::move(a);
+                    assertEmpty(a);
+
+                    a = std::make_any<any>();
+                    a = any_cast<any&&>(std::move(a)); // extract inner any
+                    assertEmpty(a);
                 }
                 {
                     // small
                     any a{small{42}};
                     a = std::move(a);
+                    assertContains<small>(a, 42);
+
+                    a = std::make_any<any>(small{42});
+                    a = any_cast<any&&>(std::move(a)); // extract inner any
+                    assertContains<small>(a, 42);
                 }
                 {
                     // large
                     any a{large{42}};
                     a = std::move(a);
+                    assertContains<large>(a, 42);
+
+                    a = std::make_any<any>(large{42});
+                    a = any_cast<any&&>(std::move(a)); // extract inner any
+                    assertContains<large>(a, 42);
                 }
                 {
                     // trivial
                     any a{int{42}};
                     a = std::move(a);
+                    assertContains<int>(a, 42);
+
+                    a = std::make_any<any>(int{42});
+                    a = any_cast<any&&>(std::move(a)); // extract inner any
+                    assertContains<int>(a, 42);
                 }
             }
 #ifdef __clang__
@@ -3160,6 +3180,40 @@ namespace msvc {
         }
 #pragma warning(pop)
     } // namespace trivial
+
+#ifndef _M_CEE // TRANSITION, VSO-1659496
+    namespace gh_140_robust_against_adl {
+        struct incomplete;
+
+        template <class T>
+        struct wrapper {
+            T t;
+        };
+
+        template <class Type>
+        void test_for() {
+            any a;
+            a = any{Type()};
+            a = any{std::in_place_type<Type>};
+            a = Type();
+            a = std::make_any<Type>();
+            a.emplace<Type>();
+            assert(any_cast<Type>(&a) != nullptr);
+        }
+
+        void run_test() {
+            using _trivial = wrapper<incomplete>*;
+            using _small   = std::pair<_trivial, small>;
+            using _large   = std::pair<_trivial, large>;
+
+            globalMemCounter.disable_allocations = true;
+            test_for<_trivial>();
+            test_for<_small>();
+            globalMemCounter.disable_allocations = false;
+            test_for<_large>();
+        }
+    } // namespace gh_140_robust_against_adl
+#endif // _M_CEE
 } // namespace msvc
 
 int main() {
@@ -3196,4 +3250,7 @@ int main() {
     msvc::size_and_alignment::run_test();
     msvc::small_type::run_test();
     msvc::trivial::run_test();
+#ifndef _M_CEE // TRANSITION, VSO-1659496
+    msvc::gh_140_robust_against_adl::run_test();
+#endif // _M_CEE
 }