https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105611
--- Comment #1 from Patrick Palka <ppalka at gcc dot gnu.org> --- std::shift_left/right require a Cpp17ForwardIterator, but here I is not default constructible which seems like a constraint violation making the testcase invalid? Using ranges::next on a legacy iterator is kind of sketchy, agreed, but I'm not sure it's wrong?
