[Bug c++/80507] [C++17] static variable definition not emitted with -std=c++1z when defined as constexpr

[arnaud02 at users dot sourceforge.net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80507

--- Comment #2 from Arnaud Desitter <arnaud02 at users dot sourceforge.net> ---
Could you explain why the code not valid C++ please?