[Bug c++/118382] [c++17] extern variable for template with default template argument should be invalid

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118382

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2025-01-09
      Known to fail|                            |7.1.0
            Summary|GCC fails to detect         |[c++17] extern variable for
                   |erroneous implicit template |template with default
                   |argument specification in   |template argument should be
                   |extern class declaration    |invalid
                   |for template class with     |
                   |default argument            |
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed. Note clang's error message is not good either.

Looks like it was introduced when automatic deduction of template arguments for
types was added.