https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124444
--- Comment #4 from François Dumont <fdumont at gcc dot gnu.org> --- Created attachment 63933 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=63933&action=edit Patch proposal It turns out that I faced this issue while working on this PR: https://forge.sourceware.org/gcc/gcc-TEST/pulls/136 I did not noticed that it came from my implementation of _GLIBCXX_DEBUG std::inplace_vector. I'm pretty sure I had no compilation issue at that time though, but clearly bug is mine. As you'll see I had worked around it by introducing a private _M_invalidate_if_impl not constexpr and add the check for __is_constant_evaluated in the inline implementation of _M_invalidate_if. So I've extracted this part from the PR and will submit it on mailing list.
