[Bug libstdc++/111327] std::bind_front (and std::not_fn) doesn't always perfectly forward according to value category of the call wrapper object

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111327

--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The example bind_front implementation in P0356R5 doesn't use deleted overloads,
despite that paper making it a perfect forwarding call wrapper. I remain
unconvinced that anybody in WG21 intended the deleted overloads when those
changes were made.