[libcxx-commits] [libcxx] Revert "[libc++] Re-enable std::pair trivial copy constructor for FreeBSD >= 14" (PR #142204)

[Dimitry Andric via libcxx-commits]

DimitryAndric wrote:

Originally the plan was to wait until libc++ bumped its official ABI to 2, then go with that instead, so as to avoid have to break the FreeBSD base system's ABI more than once. But for some reason libc++ has stayed in ABI v1 for years now. :)

I'd say that it depends on whether libc++ will ever ship ABI v2, if that is still another number of years out then it might make sense to at least break the std::pair ABI for FreeBSD 15. Which will involve bumping our libc++.so.1 to something higher, likely libc++.so.2. We've painted ourselves into a corner with that: if libc++ at some point ships ABI v2 and bumps its own soname to .2 it's going to be very confusing...

https://github.com/llvm/llvm-project/pull/142204