[Bug c++/97661] Bogus error message about initializing a using declaration

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97661

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mpolacek at gcc dot gnu.org
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2020-11-03
     Ever confirmed|0                           |1

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
template <typename...> struct A {};
struct B : A<> {};
template <typename...> struct C {
  A<> *a;
  using V = A<>;
};

C(A<> *)->C<>;

template<typename T> auto declval() -> decltype(T());
template<typename T, typename = typename decltype(C{declval<T *>()})::V> struct
D;
template<typename> struct J { };
template<typename T> using U = J<D<T>>;

void
fn ()
{
  U<B> u;
}