[libcxx-commits] [libcxx] [libc++] P2641R4: Checking if a `union` alternative is active (`std::is_within_lifetime`) (PR #165243)

[A. Jiang via libcxx-commits]

================
@@ -0,0 +1,26 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20, c++23
+// UNSUPPORTED: clang-18, clang-19, gcc-14, apple-clang-16
----------------
frederick-vs-ja wrote:

```suggestion
// REQUIRES: std-at-least-c++26
// UNSUPPORTED: gcc-15, apple-clang-17
```
Although GCC doesn't seem to be used here.

https://github.com/llvm/llvm-project/pull/165243