[Bug c++/95725] Confusing error diagnostic in an invalid template

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95725

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |msebor at gcc dot gnu.org

--- Comment #3 from Martin Sebor <msebor at gcc dot gnu.org> ---
The diagnostic is usually for false positive/negative warnings or wrong
information in diagnostic messages.  It's not normally used for internal
compiler errors.  But I don't see an ICE on trunk with this test case, just
errors (so diagnostic would seem appropriate).  At the same time, the latest
GCC output seems reasonable.  Clang prints something similar:

pr95725.C:1:20: error: expected expression
template <decltype(= ;
                   ^
pr95725.C:1:22: error: expected expression
template <decltype(= ;
                     ^
pr95725.C:1:22: error: expected ',' or '>' in template-parameter-list
pr95725.C:1:22: warning: declaration does not declare anything
      [-Wmissing-declarations]
1 warning and 3 errors generated.

I'm not sure there's a lot to improve here.