[Bug libstdc++/80564] bind on SFINAE unfriendly generic lambda

[rs2740 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80564

TC <rs2740 at gmail dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |rs2740 at gmail dot com

--- Comment #4 from TC <rs2740 at gmail dot com> ---
(In reply to Eric Fiselier from comment #3)
> Here is an example of why `_Bind::operator()(...) const` must be considered
> during overload resolution even if the call wrapper itself is not const.
> 
> ------------------------------
> #include <functional>
> 
> struct Func {
>   template <class ...Args>
>   void operator()(Args&&...) = delete;
> 
>   template <class ...Args>
>   void operator()(Args&&...) const {}
> };
> 
> int main() {
>     Func f;
>     std::bind(f)();
> }
> -------------------------

Interesting, libstdc++ rejects this as an attempt to call a deleted function.
That seems more correct than libc++'s approach which calls the const overload.