[Bug c++/109181] requires expression type requirement rejects valid type when it is a nested member template

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109181

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2023-03-18
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
      Known to fail|                            |10.1.0, 12.1.0, 13.0,
                   |                            |6.1.0, 7.1.0

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed.
Goes away the way back when -fconcepts support was originally added in GCC 6.
You can see that with this testcase:
```
struct A {
    template<typename>
    using B = int;
};

template<typename T>
bool go = requires{typename A::template B<T>;};
```

Note back in GCC 6, you needed `-std=c++17 -fconcepts` and also requires was
only allowed for templates too ..