[Bug c++/127987] [reflection] Auto type deduction on ill-formed reflection: Should that compile ?

[songb432 at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127987

--- Comment #1 from songb432 at gmail dot com ---
As a comparison:
Link: https://godbolt.org/z/7GEMoc7qo
``
template <class T>
  struct S
  {
    static constexpr auto refl()
    { return ^^typename T::type; }
  };

S<int> s; // OK.

template <class T> concept C = requires { S<T>::refl(); };
static_assert(C<int> || !C<int>); // Both GCC and Clang reject this; hard
error.
``