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| author | Jonathan Wakely <jwakely@redhat.com> | 2021-06-14 12:30:52 +0100 |
|---|---|---|
| committer | Jonathan Wakely <jwakely@redhat.com> | 2021-06-14 14:04:45 +0100 |
| commit | b76a529c095f076c4780df0c913cf6d2391bcbc9 (patch) | |
| tree | 41e756b31f8630c27d74059a49559d41ce32c154 | |
| parent | e2c79b968ff95421c31a5a9a1b80b11321fe70d2 (diff) | |
| download | gcc-b76a529c095f076c4780df0c913cf6d2391bcbc9.zip gcc-b76a529c095f076c4780df0c913cf6d2391bcbc9.tar.gz gcc-b76a529c095f076c4780df0c913cf6d2391bcbc9.tar.bz2 | |
libstdc++: Implement LWG 3465 for std::compare_partial_order_fallback [PR101056]
libstdc++-v3/ChangeLog:
PR libstdc++/101056
* libsupc++/compare (compare_partial_order_fallback): Add
constraint using reversed parameter order, as per LWG 3465.
* testsuite/18_support/comparisons/algorithms/fallback.cc:
Adjust expected result.
| -rw-r--r-- | libstdc++-v3/libsupc++/compare | 14 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/18_support/comparisons/algorithms/fallback.cc | 2 |
2 files changed, 13 insertions, 3 deletions
diff --git a/libstdc++-v3/libsupc++/compare b/libstdc++-v3/libsupc++/compare index b1f3421..dd0ec5f 100644 --- a/libstdc++-v3/libsupc++/compare +++ b/libstdc++-v3/libsupc++/compare @@ -806,6 +806,16 @@ namespace std } }; + // _GLIBCXX_RESOLVE_LIB_DEFECTS + // 3465. compare_partial_order_fallback requires F < E + template<typename _Tp, typename _Up> + concept __op_eq_lt_lt = __op_eq_lt<_Tp, _Up> + && requires(_Tp&& __t, _Up&& __u) + { + { static_cast<_Up&&>(__u) < static_cast<_Tp&&>(__t) } + -> convertible_to<bool>; + }; + class _Partial_fallback { template<typename _Tp, typename _Up> @@ -821,7 +831,7 @@ namespace std public: template<typename _Tp, __decayed_same_as<_Tp> _Up> - requires __partially_ordered<_Tp, _Up> || __op_eq_lt<_Tp, _Up> + requires __partially_ordered<_Tp, _Up> || __op_eq_lt_lt<_Tp, _Up> constexpr partial_ordering operator()(_Tp&& __e, _Up&& __f) const noexcept(_S_noexcept<_Tp, _Up>()) @@ -829,7 +839,7 @@ namespace std if constexpr (__partially_ordered<_Tp, _Up>) return _Partial_order{}(static_cast<_Tp&&>(__e), static_cast<_Up&&>(__f)); - else // __op_eq_lt<_Tp, _Up> + else // __op_eq_lt_lt<_Tp, _Up> return static_cast<_Tp&&>(__e) == static_cast<_Up&&>(__f) ? partial_ordering::equivalent : static_cast<_Tp&&>(__e) < static_cast<_Up&&>(__f) diff --git a/libstdc++-v3/testsuite/18_support/comparisons/algorithms/fallback.cc b/libstdc++-v3/testsuite/18_support/comparisons/algorithms/fallback.cc index ae45852..05e1bf7 100644 --- a/libstdc++-v3/testsuite/18_support/comparisons/algorithms/fallback.cc +++ b/libstdc++-v3/testsuite/18_support/comparisons/algorithms/fallback.cc @@ -38,5 +38,5 @@ static_assert( has_weak_order_fallback<S, S> ); static_assert( has_weak_order_fallback<const S, S> ); static_assert( ! has_weak_order_fallback<const S, const S> ); static_assert( has_partial_order_fallback<S, S> ); -static_assert( has_partial_order_fallback<const S, S> ); +static_assert( ! has_partial_order_fallback<const S, S> ); // LWG 3465 static_assert( ! has_partial_order_fallback<const S, const S> ); |