https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100631
--- Comment #7 from 康桓瑋 <hewillk at gmail dot com> --- (In reply to CVS Commits from comment #6) > The master branch has been updated by Patrick Palka <ppa...@gcc.gnu.org>: > > https://gcc.gnu.org/g:2e2eef80ac0c21f9533e6791ccf5e29458cbb77c > > commit r12-854-g2e2eef80ac0c21f9533e6791ccf5e29458cbb77c > Author: Patrick Palka <ppa...@redhat.com> > Date: Tue May 18 00:26:07 2021 -0400 > > libstdc++: Fix miscellaneous issues with elements_view::_Sentinel > [PR100631] > > libstdc++-v3/ChangeLog: > > PR libstdc++/100631 > * include/std/ranges (elements_view::_Iterator): Also befriend > _Sentinel<!_Const>. > (elements_view::_Sentinel::_M_equal): Templatize. > (elements_view::_Sentinel::_M_distance_from): Split out from ... > (elements_view::_Sentinel::operator-): ... here. Depend on > _Base2 instead of _Base in the return type. > * testsuite/std/ranges/adaptors/elements.cc (test06, test07): > New tests. Hey, Patrick, you missed the second one: template<bool _Const2, typename _Base2 = __detail::__maybe_const_t<_Const2, _Vp>> requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base2>> friend constexpr range_difference_t<_Base2> operator-(const _Iterator<_Const2>& __x, const _Sentinel& __y) { return __x._M_current - __y._M_end; } this should be return -__y._M_distance_from(__x).
