https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80762
--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> --- Author: redi Date: Thu Jan 10 16:06:49 2019 New Revision: 267815 URL: https://gcc.gnu.org/viewcvs?rev=267815&root=gcc&view=rev Log: PR libstdc++/80762 avoid ambiguous __constructible_from<void, void> Ensure we don't try to instantiate __is_constructible_from<void, void>, because there are two partial specializations that are equally good matches. Backport from mainline 2018-12-12 Jonathan Wakely <jwak...@redhat.com> PR libstdc++/80762 * include/bits/fs_path.h (path::_Path): Use remove_cv_t and is_void. * include/experimental/bits/fs_path.h (path::_Path): Likewise. * testsuite/27_io/filesystem/path/construct/80762.cc: New test. * testsuite/experimental/filesystem/path/construct/80762.cc: New test. Added: branches/gcc-8-branch/libstdc++-v3/testsuite/27_io/filesystem/path/construct/80762.cc branches/gcc-8-branch/libstdc++-v3/testsuite/experimental/filesystem/path/construct/80762.cc Modified: branches/gcc-8-branch/libstdc++-v3/ChangeLog branches/gcc-8-branch/libstdc++-v3/include/bits/fs_path.h branches/gcc-8-branch/libstdc++-v3/include/experimental/bits/fs_path.h