https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117293
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #1)
> I am not sure this is related to SFINAE though.
>
> Rather it is in an unevaluated context where the diagnostic of deprecated
> should not happen.
But it is even odder than that.
The problem is you need to match decltype(void(Dst{declval<Src>()})) to void
which it does.
Note if I comment out:
```
Bar(const string&);
```
then the template overload is selected. And I would have expected a warning
from clang/EDG/MSVC for the deprecated constructor but nothing.
I am not 100% sure this if this warning is expected or not.
So I don't think there is a leak here either since you need to see if which of
the constructors is valid or not and then select based on which one is more
specialized or not.
Note using C++ 20 concepts does not warn.
