https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120934
--- Comment #4 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Patrick Palka <ppa...@gcc.gnu.org>: https://gcc.gnu.org/g:c5a17e92ebf0c6f3887fb5698a1114a3fdf50576 commit r16-1986-gc5a17e92ebf0c6f3887fb5698a1114a3fdf50576 Author: Patrick Palka <ppa...@redhat.com> Date: Thu Jul 3 10:55:17 2025 -0400 libstdc++: Update LWG 4166 changes to concat_view::end() [PR120934] In r15-4555-gf191c830154565 we proactively implemented the initial proposed resolution for LWG 4166 which later turned out to be insufficient, since we must also require equality_comparable of the underlying iterators before concat_view could be a common range. This patch implements the updated P/R, requiring all underlying iterators to be forward (which implies equality_comparable) before making concat_view common, which fixes the testcase from this PR. PR libstdc++/120934 libstdc++-v3/ChangeLog: * include/std/ranges (concat_view::end): Refine condition for returning an iterator instead of default_sentinel as per the updated P/R for LWG 4166. * testsuite/std/ranges/concat/1.cc (test05): New test. Reviewed-by: Jonathan Wakely <jwak...@redhat.com>
