https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80675
--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-11 branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:ca7d2f2ec9142995179a5d832a946b50de05e659 commit r11-8369-gca7d2f2ec9142995179a5d832a946b50de05e659 Author: Jonathan Wakely <jwak...@redhat.com> Date: Fri Apr 30 14:07:28 2021 +0100 libstdc++: Implement LWG 1203 for rvalue iostreams This implements the resolution of LWG 1203 so that the constraints for rvalue stream insertion/extraction are simpler, and the return type is the original rvalue stream type not its base class. Signed-off-by: Jonathan Wakely <jwak...@redhat.com> libstdc++-v3/ChangeLog: * include/std/istream (operator>>(Istream&&, x&)): Simplify, as per LWG 1203. * include/std/ostream (operator<<(Ostream&&, const x&)): Likewise. * testsuite/27_io/basic_istream/extractors_character/char/lwg2499_neg.cc: Adjust dg-error pattern. * testsuite/27_io/basic_istream/extractors_character/wchar_t/lwg2499_neg.cc: Likewise. * testsuite/27_io/basic_istream/extractors_other/char/4.cc: Define is_extractable trait to replace std::__is_extractable. Make it work with rvalue streams as well as lvalues, to replace f() and g() helper functions. * testsuite/27_io/basic_istream/extractors_other/wchar_t/4.cc: Likewise. * testsuite/27_io/basic_ostream/inserters_other/char/6.cc: Define is_insertable trait to replace std::__is_insertable. Make it work with rvalue streams as well as lvalues, to replace f() and g() helper functions. * testsuite/27_io/basic_ostream/inserters_other/wchar_t/6.cc: Likewise. * testsuite/27_io/filesystem/path/io/dr2989.cc: Prune additional errors from new constraints. * testsuite/27_io/rvalue_streams-2.cc: Remove PR 80675 checks, which are no longer expected to compile. * testsuite/27_io/rvalue_streams.cc: Adjust existing test. Verify LWG 1203 changes. (cherry picked from commit aa475c4ac80733f85ba47b109fc1900f05e810e2)
