On Mon, 31 Mar 2025 at 15:53, Tomasz Kaminski <tkami...@redhat.com> wrote: > > > > On Mon, Mar 31, 2025 at 3:03 PM Jonathan Wakely <jwak...@redhat.com> wrote: >> >> The boolean-testable requirements don't require the type to be copyable, >> so we need to convert to bool before it might need to be copied. >> >> libstdc++-v3/ChangeLog: >> >> PR libstdc++/119545 >> * include/std/tuple (operator==): Convert comparison results to >> bool. >> * testsuite/20_util/tuple/comparison_operators/119545.cc: New >> test. >> --- >> >> Tested x86_64-linux. > > LGTM. >> >> >> For the recent r15-7897-ge6e7b477bbdbfb change to fix a similar problem >> I used an explicit return type on the lambda, because that was what the >> LWG issue said to do. In this case an explicit return type would also >> work, but I used an explicit conversion to bool on each element of the >> pack expansion instead. > > boolean-testable requirements allows you to do that: a && b on > boolean-testable a, bis > required to have the same behavior bool(a) && bool(b), so all good. > >> >> That matches what is done elsewhere in <tuple> >> for the tuple-like equality comparison, so I preferred to be locally >> consistent. > > We also are no longer triggering lookup for opeartor&& on boolean-testable, > which is required to find nothing, but still will be performed. So I think > converting > to bool before applying &&/|| on boolean-testable is good idea.
Yes, that did occur to me. But I decided that all sane comparisons return bool anyway so the benefit was mostly theoretical :-) Thanks for the review.
