[Bug c++/116121] GCC rejects valid program involving explicit specialization of static data member without specializing the class template itself

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116121

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
EDG accepts this too.

So in summary it is:
GCC and MSVC reject it for the same reason.
EDG and clang accept it.