https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90165
--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> --- Author: redi Date: Tue May 7 15:46:36 2019 New Revision: 270966 URL: https://gcc.gnu.org/viewcvs?rev=270966&root=gcc&view=rev Log: PR libstdc++/90165 constrain variant(T&&) constructor Backport from mainline 2019-04-23 Jonathan Wakely <jwak...@redhat.com> PR libstdc++/90165 * include/std/variant (variant::__is_in_place_tag) (variant::__not_in_place_tag): New helpers for variant(T&&) constructor constraint. (variant::variant(T&&)): Use __not_in_place_tag in constraints. * testsuite/20_util/variant/compile.cc: Check variant(T&&) constructor isn't used for in_place_type or in_place_index arguments. Modified: branches/gcc-8-branch/libstdc++-v3/ChangeLog branches/gcc-8-branch/libstdc++-v3/include/std/variant branches/gcc-8-branch/libstdc++-v3/testsuite/20_util/variant/compile.cc