[libcxx-commits] [libcxx] [libcxx] Implementation of P1831R1 (PR #101439)

[A. Jiang via libcxx-commits]

frederick-vs-ja wrote:

> It seems like adding `[[deprecated]]` / `_LIBCPP_DEPRECATED_IN_CXX11` to template specializations does not emit a warning, the attribute is seemingly ignored unless the base template has the attribute (which would not make sense here).

In any case, it's probably `_LIBCPP_DEPRECATED_IN_CXX20` or conditional compilation on `_LIBCPP_STD_VER >= 20` that should be used.

I think we should continue to add the attribute since it works with GCC.

For Clang, I think I have a partial workaround but it's unknown whethere there's a complete one, see https://github.com/llvm/llvm-project/issues/44496#issuecomment-2264382239. Note there're currently pitfalls.

https://github.com/llvm/llvm-project/pull/101439