https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91073
--- Comment #9 from Jonathan Wakely <redi at gcc dot gnu.org> --- Author: redi Date: Tue Dec 3 23:57:46 2019 New Revision: 278951 URL: https://gcc.gnu.org/viewcvs?rev=278951&root=gcc&view=rev Log: libstdc++: Implement spaceship for std::pair (P1614R2) This defines operator<=> as a non-member function template and does not alter operator==. This contradicts the changes made by P1614R2, which specify both as hidden friends, but that specification of operator<=> is broken and the subject of a soon-to-be-published LWG issue. * include/bits/stl_pair.h [__cpp_lib_three_way_comparison] (operator<=>): Define for C++20. * libsupc++/compare (__cmp2way_res_t): Rename to __cmp3way_res_t, move into __detail namespace. Do not turn argument types into lvalues. (__cmp3way_helper): Rename to __cmp3way_res_impl, move into __detail namespace. Constrain with concepts instead of using void_t. (compare_three_way_result): Adjust name of base class. (compare_three_way_result_t): Use __cmp3way_res_impl directly. (__detail::__3way_cmp_with): Add workaround for PR 91073. (compare_three_way): Use workaround. (__detail::__synth3way, __detail::__synth3way_t): Define new helpers implementing synth-three-way and synth-three-way-result semantics. * testsuite/20_util/pair/comparison_operators/constexpr_c++20.cc: New test. Added: trunk/libstdc++-v3/testsuite/20_util/pair/comparison_operators/constexpr_c++20.cc Modified: trunk/libstdc++-v3/ChangeLog trunk/libstdc++-v3/include/bits/stl_pair.h trunk/libstdc++-v3/libsupc++/compare
