https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115209
--- Comment #6 from 康桓瑋 <hewillk at gmail dot com> --- (In reply to Patrick Palka from comment #5) > (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. But that resolution is *not quite right* and is not set for WP.
