https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116722
--- Comment #8 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #1)
> Note GCC 11.4.0 didn't ICE but accepted the code. clang/MSVC/EDG all reject
> the constexpr in a class with a virtual base class.
>
> Without a template GCC does reject the constexpr constructor because it is a
> class with a virtual base class BUT the error message is not exactly clear
> there:
> ```
> <source>: In constructor 'constexpr derived::derived(int)':
> <source>:5:29: error: 'class derived' has virtual base classes
> 5 | constexpr derived(int) {}
> | ^
> ```
> (but that is a different issue all together).
Did that accepts-invalid issue ever get reported?
