[Bug c++/24847] Instantiates un-called copy constructor

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=24847

--- Comment #7 from Drea Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #6)
> Or in C++20:
> 
> explicit    foo(foo<T, 0, x>) requires (i != 0);

Note the C++20 example here is still invalid code see PR 101113 details on why.