https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119034
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #2)
> This is odd, doing this:
> ```
> namespace foo
> {
> struct X { };
> void func(X) { }
> }
>
> namespace bar
> {
> int func() = delete;
> template<typename T>
> using type = decltype(func(T{})); // #2
> }
>
> template<typename, typename> constexpr bool is_same_v = false;
> template<typename T> constexpr bool is_same_v<T, T> = true;
>
> static_assert( is_same_v<bar::type<foo::X>, void> );
> ```
>
> Works
This started to work in GCC 12 (a variant of it [changing the template
variable] was failing since at least 4.9.0) so that might give an hint of where
the problem is located.
