https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110853
--- Comment #8 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Patrick Palka from comment #6)
> (In reply to Jonathan Wakely from comment #5)
> > This is a regression caused by the new concepts-based constructor
> > constraints in gcc 12.
> And the analogous std::tuple example started failing after r13-54 (with
> -std=c++17).
Ugh, so it does:
#include <tuple>
void func() {}
std::tuple t(func);
std::tuple<void (*)()>& r = t;
r13-54 was backported as r12-8379 so this fails since 12.2
