[Bug c++/94126] [concepts] suboptimal diagnostic when type after substitution is ill-formed

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94126

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
   Target Milestone|---                         |10.0
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #1 from Patrick Palka <ppalka at gcc dot gnu.org> ---
With current trunk and -fconcepts-diagnostics-depth=2, we now get:


disj.cc:13:15: error: static assertion failed
   13 | static_assert(E<int>);
      |               ^~~~~~
disj.cc:13:15: note: constraints not satisfied
disj.cc:8:11:   required for the satisfaction of ‘D<typename T::type>’ [with T
= int]
disj.cc:8:20: note: no operand of the disjunction is satisfied
    8 |   concept D = C<T> || C<const T>;
      |               ~~~~~^~~~~~~~~~~~~
disj.cc:8:15: note: the operand ‘C<T>’ is unsatisfied because
    8 |   concept D = C<T> || C<const T>;
      |               ^~~~~~~~~~~~~~~~~~
disj.cc:5:11:   required for the satisfaction of ‘C<T>’ [with T = typename
T::type]
disj.cc:8:11:   required for the satisfaction of ‘D<typename T::type>’ [with T
= int]
disj.cc:13:15: error: ‘int’ is not a class, struct, or union type
   13 | static_assert(E<int>);
      |               ^~~~~~
disj.cc:8:23: note: the operand ‘C<const T>’ is unsatisfied because
    8 |   concept D = C<T> || C<const T>;
      |               ~~~~~~~~^~~~~~~~~~
disj.cc:5:11:   required for the satisfaction of ‘C<const T>’ [with T =
typename T::type]
disj.cc:8:11:   required for the satisfaction of ‘D<typename T::type>’ [with T
= int]
disj.cc:13:15: error: ‘int’ is not a class, struct, or union type
   13 | static_assert(E<int>);
      |               ^~~~~~


So I'm considering this fixed.