[libcxx-commits] [libcxx] [libc++] Allow a disengaged `optional` to be `constexpr` since C++20 (PR #192888)

[A. Jiang via libcxx-commits]

frederick-vs-ja wrote:

Perhaps the implementation status of CWG issues is track in these pages. Although there're too many "unknown" entries.
- https://gcc.gnu.org/projects/cxx-dr-status.html
- https://clang.llvm.org/cxx_dr_status.html

https://github.com/llvm/llvm-project/pull/192888