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

[Hristo Hristov via libcxx-commits]

H-G-Hristov wrote:

This is missing a release note.

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