[Bug libstdc++/71899] An internal BooleanTestable trait should be provided

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71899

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
LWG 2743 seems to be the wrong issue, I think https://wg21.link/lwg2114 is the
right one.