https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77727
--- Comment #6 from ville at gcc dot gnu.org --- Author: ville Date: Mon Oct 24 12:52:31 2016 New Revision: 241477 URL: https://gcc.gnu.org/viewcvs?rev=241477&root=gcc&view=rev Log: Backport from mainline: 2016-10-24 Ville Voutilainen <ville.voutilai...@gmail.com> Cross-port the latest resolution of LWG2756 and some bug-fixes to experimental::optional. PR libstdc++/77288 PR libstdc++/77727 * include/experimental/optional (_Optional_base): Remove constructors that take a _Tp. (__is_optional_impl, __is_optional): Remove. (__converts_from_optional): New. (optional(_Up&&)): Fix constraints, call base with in_place. (optional(const optional<_Up>&)): Fix constraints, use emplace. (optional(optional<_Up>&&)): Likewise. (operator=(_Up&&)): Fix constraints. (operator=(const optional<_Up>&)): Likewise. (operator=(optional<_Up>&&)): Likewise. (emplace(_Args&&...)): Constrain. (emplace(initializer_list<_Up>, _Args&&...)): Likewise. * testsuite/experimental/optional/77288.cc: New. * testsuite/experimental/optional/assignment/5.cc: Adjust. * testsuite/experimental/optional/cons/77727.cc: New. * testsuite/experimental/optional/cons/value.cc: Adjust. Added: branches/gcc-6-branch/libstdc++-v3/testsuite/experimental/optional/77288.cc branches/gcc-6-branch/libstdc++-v3/testsuite/experimental/optional/cons/77727.cc - copied, changed from r241461, branches/gcc-6-branch/libstdc++-v3/testsuite/experimental/optional/assignment/5.cc Modified: branches/gcc-6-branch/libstdc++-v3/ChangeLog branches/gcc-6-branch/libstdc++-v3/include/experimental/optional branches/gcc-6-branch/libstdc++-v3/testsuite/experimental/optional/assignment/5.cc branches/gcc-6-branch/libstdc++-v3/testsuite/experimental/optional/cons/value.cc
