[Bug c++/119866] constexpr with __builtin_strlen does not always work

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119866

--- Comment #8 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Barry Revzin from comment #3)
> At this point lots of code relies on that working.

I think it was never intentionally supported in constexpr (it just happened to
work) and so such code was never correct.