https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125729
--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
A similar test that ICEs the same:
```
template <decltype(^^void) type>
struct Error
{
Error() {}
};
consteval decltype(^^void)
fn1 ()
{
using Type = int; return ^^Type;
}
consteval decltype(^^void)
fn2 ()
{
using Type = int; return ^^Type;
}
Error<fn1()> c{};
Error<fn2()> d{};
```
