[Bug c++/86998] Improve diagnostic for missing comma in template-parameter-list

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86998

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2018-08-17
     Ever confirmed|0                           |1

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The ideal would be a fix-it hint suggesting to add the comma.

Adding the '>' that the parser says is expected would not make the code correct
because 'template<typename T> typename U>' isn't valid as a top-level
declaration (only as a template-parameter).