[Bug libstdc++/100381] [11/12 Regression] new static_assert((std::__is_complete_or_unbounded(...)) failure from g++ 11.1.0

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100381

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
This is almost certainly invalid code. Implementations are not required to
enforce the complete type precondition, so "other compilers don't reject it"
doesn't mean much. If the code has undefined behaviour then it's conforming to
accept it silently, or to reject it like this.

I haven't analyzed it in detail yet though.