[libcxx-commits] [libcxx] [libcxx] improves diagnostics for containers with bad value types (PR #106296)

[Louis Dionne via libcxx-commits]

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@@ -0,0 +1,50 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___TYPE_TRAITS_DIAGNOSTIC_UTILITIES_H
+#define _LIBCPP___TYPE_TRAITS_DIAGNOSTIC_UTILITIES_H
+
+#include <__config>
+#include <__type_traits/is_bounded_array.h>
+#include <__type_traits/is_const.h>
+#include <__type_traits/is_function.h>
+#include <__type_traits/is_reference.h>
+#include <__type_traits/is_unbounded_array.h>
+#include <__type_traits/is_void.h>
+#include <__type_traits/is_volatile.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER >= 20
+#  define _LIBCPP_CHECK_CONTAINER_VALUE_TYPE_IS_NOT_ARRAY_BEFORE_CXX20(_Template, _Tp, _Verb)
+#else
+#  define _LIBCPP_CHECK_CONTAINER_VALUE_TYPE_IS_NOT_ARRAY_BEFORE_CXX20(_Template, _Tp, _Verb)                          \
+    ;                                                                                                                  \
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ldionne wrote:

Instead, you can define `_LIBCPP_CHECK_CONTAINER_VALUE_TYPE_IS_NOT_ARRAY_BEFORE_CXX20` to `static_assert(true, "")` and simplify the semi-colon tricks.

https://github.com/llvm/llvm-project/pull/106296