https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96222
Jonathan Wakely <redi at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID --- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> --- That's because it's iterator category is input_iterator_tag and input iterators are single pass. See https://en.cppreference.com/w/cpp/named_req/InputIterator So this is not a bug.