https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89102
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- Author: redi Date: Wed Feb 6 17:25:26 2019 New Revision: 268586 URL: https://gcc.gnu.org/viewcvs?rev=268586&root=gcc&view=rev Log: PR libstdc++/89102 fix common_type<> and common_type<T> specializations This is a partial implementation of the revised std::common_type rules from P0435R1. PR libstdc++/89102 (partial) * include/std/type_traits (common_type<>): Define. (common_type<T>): Derive from common_type<T, T>. * testsuite/20_util/common_type/requirements/explicit_instantiation.cc: Test zero-length template argument list. * testsuite/20_util/common_type/requirements/sfinae_friendly_1.cc: Test additional single argument cases. * testsuite/20_util/common_type/requirements/sfinae_friendly_2.cc: Adjust expected error. Modified: trunk/libstdc++-v3/ChangeLog trunk/libstdc++-v3/include/std/type_traits trunk/libstdc++-v3/testsuite/20_util/common_type/requirements/explicit_instantiation.cc trunk/libstdc++-v3/testsuite/20_util/common_type/requirements/sfinae_friendly_1.cc trunk/libstdc++-v3/testsuite/20_util/common_type/requirements/sfinae_friendly_2.cc
