https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115209
--- Comment #5 from Patrick Palka <ppalka at gcc dot gnu.org> --- (In reply to 康桓瑋 from comment #4) > > Our concat_view implementation is accidentally based off of an older > > revision of the paper, P2542R7 instead of R8. As far as I can tell the > > only semantic change in the final revision is the relaxed constraints on > > the iterator's iter/sent operator- overloads, which this patch updates. > > But the end() does not have the std::semiregular constraint so far as I can > tell. That comes from the original P/R for LWG 4166 which we proactively implemented.
