[Bug libstdc++/113074] requires requires should be SFINAE

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113074

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
https://eel.is/c++draft/memory#pointer.conversion


As far as I can tell, std::to_address is not required to be SFINAE safe ...

The standard just says:
```
Returns: pointer_traits<Ptr>​::​to_address(p) if that expression is well-formed
(see [pointer.traits.optmem]), otherwise to_address(p.operator->()).
```