[libcxx-commits] [libcxx] [libc++] Replace `std::optional` in `__format/format_context.h` with a re-implementation (PR #148876)

[Louis Dionne via libcxx-commits]

ldionne wrote:

I tend to agree: I would try to break the circular dependency some other way (e.g. a forward declaration header) in order to avoid reimplementing `optional`.

https://github.com/llvm/llvm-project/pull/148876