[libcxx-commits] [libcxx] [libc++] Replace `__compressed_pair` with `[[no_unique_address]]` (PR #76756)

[Louis Dionne via libcxx-commits]

ldionne wrote:

I just discussed with @philnik777 and I realized that this requires support for `[[no_unique_address]]` in C++03 mode. This seems to have landed in Clang 17, however there is no currently released AppleClang version that supports the feature, so this patch will have to sit around for a bit until we drop support for AppleClang 15. This is unfortunate, but it means this patch will likely land in the LLVM 20 time frame instead of LLVM 19, as we want to land it early in a release cycle.

https://github.com/llvm/llvm-project/pull/76756