[Bug c++/126280] [13/14/15/16/17 Regression] "used but never defined" SFINAE warning for function template in specific circumstances with fold expression

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126280

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |11.5.0
   Target Milestone|---                         |13.5
            Summary|"used but never defined"    |[13/14/15/16/17 Regression]
                   |SFINAE warning for function |"used but never defined"
                   |template in specific        |SFINAE warning for function
                   |circumstances with fold     |template in specific
                   |expression                  |circumstances with fold
                   |                            |expression