[libcxx-commits] [libcxx] [libc++] Cooperation between `std::optional` and other standard types (PR #93672)

[A. Jiang via libcxx-commits]

frederick-vs-ja wrote:

> However, the dependence on `__builtin_is_within_lifetime` and the need to add `launder` and other scary foot guns throughout the code makes me rather concerned.

I don't think `launder` is necessary after [P1917R0 RU007](https://wg21.link/p1971r0#RU007) and [P2103R0 US041](https://wg21.link/p2103r0#US041) (both of which should be treated as DR).

https://github.com/llvm/llvm-project/pull/93672