P2968R2 Make std::ignore A First-Class Object (#4777)

NeilGeorge1 · web-flow · commit 4406e0e251e2 · 2024-07-05T00:11:41.000-07:00
diff --git a/stl/inc/tuple b/stl/inc/tuple
@@ -119,16 +119,6 @@ struct _Tuple_perfect_val<tuple<_Ty0, _Ty1, _Ty2>, _Uty0, _Uty1, _Uty2>
     : bool_constant<disjunction_v<negation<is_same<_Remove_cvref_t<_Uty0>, allocator_arg_t>>,
           is_same<_Remove_cvref_t<_Ty0>, allocator_arg_t>>> {};
 
-struct _Ignore { // struct that ignores assignments
-    template <class _Ty>
-    constexpr const _Ignore& operator=(const _Ty&) const noexcept /* strengthened */ {
-        // do nothing
-        return *this;
-    }
-};
-
-_EXPORT_STD _INLINE_VAR constexpr _Ignore ignore{};
-
 // Note: To improve throughput, this file uses extra _STD qualification for names that appear in the
 // arguments of enable_if_t. Specifically, we qualify names which appear anywhere in the STL as members of
 // some class - including injected-class-names! - that we know are not members of the class being defined.
diff --git a/stl/inc/utility b/stl/inc/utility
@@ -134,6 +134,16 @@ _EXPORT_STD struct piecewise_construct_t { // tag type for pair tuple arguments
 
 _EXPORT_STD _INLINE_VAR constexpr piecewise_construct_t piecewise_construct{};
 
+struct _Ignore { // struct that ignores assignments
+    template <class _Ty>
+    constexpr const _Ignore& operator=(const _Ty&) const noexcept {
+        // do nothing
+        return *this;
+    }
+};
+
+_EXPORT_STD _INLINE_VAR constexpr _Ignore ignore{};
+
 _EXPORT_STD template <class... _Types>
 class tuple;
 
diff --git a/stl/inc/yvals_core.h b/stl/inc/yvals_core.h
@@ -79,6 +79,7 @@
 // P2407R5 Freestanding Library: Partial Classes
 //     (__cpp_lib_freestanding_algorithm and __cpp_lib_freestanding_array only)
 // P2937R0 Freestanding Library: Remove strtok
+// P2968R2 Make std::ignore A First-Class Object
 
 // _HAS_CXX17 directly controls:
 // P0005R4 not_fn()
