1*4bdff4beSrobert //===----------------------------------------------------------------------===// 2*4bdff4beSrobert // 3*4bdff4beSrobert // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*4bdff4beSrobert // See https://llvm.org/LICENSE.txt for license information. 5*4bdff4beSrobert // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*4bdff4beSrobert // 7*4bdff4beSrobert //===----------------------------------------------------------------------===// 8*4bdff4beSrobert 9*4bdff4beSrobert #ifndef _LIBCPP___COMPARE_WEAK_ORDER 10*4bdff4beSrobert #define _LIBCPP___COMPARE_WEAK_ORDER 11*4bdff4beSrobert 12*4bdff4beSrobert #include <__compare/compare_three_way.h> 13*4bdff4beSrobert #include <__compare/ordering.h> 14*4bdff4beSrobert #include <__compare/strong_order.h> 15*4bdff4beSrobert #include <__config> 16*4bdff4beSrobert #include <__type_traits/decay.h> 17*4bdff4beSrobert #include <__utility/forward.h> 18*4bdff4beSrobert #include <__utility/priority_tag.h> 19*4bdff4beSrobert #include <cmath> 20*4bdff4beSrobert 21*4bdff4beSrobert #ifndef _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER 22*4bdff4beSrobert # pragma GCC system_header 23*4bdff4beSrobert #endif 24*4bdff4beSrobert 25*4bdff4beSrobert _LIBCPP_BEGIN_NAMESPACE_STD 26*4bdff4beSrobert 27*4bdff4beSrobert #if _LIBCPP_STD_VER > 17 28*4bdff4beSrobert 29*4bdff4beSrobert // [cmp.alg] 30*4bdff4beSrobert namespace __weak_order { 31*4bdff4beSrobert struct __fn { 32*4bdff4beSrobert // NOLINTBEGIN(libcpp-robust-against-adl) weak_order should use ADL, but only here 33*4bdff4beSrobert template<class _Tp, class _Up> 34*4bdff4beSrobert requires is_same_v<decay_t<_Tp>, decay_t<_Up>> 35*4bdff4beSrobert _LIBCPP_HIDE_FROM_ABI static constexpr auto 36*4bdff4beSrobert __go(_Tp&& __t, _Up&& __u, __priority_tag<3>) 37*4bdff4beSrobert noexcept(noexcept(weak_ordering(weak_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))))) 38*4bdff4beSrobert -> decltype( weak_ordering(weak_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u)))) 39*4bdff4beSrobert { return weak_ordering(weak_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))); } 40*4bdff4beSrobert // NOLINTEND(libcpp-robust-against-adl) 41*4bdff4beSrobert 42*4bdff4beSrobert template<class _Tp, class _Up, class _Dp = decay_t<_Tp>> 43*4bdff4beSrobert requires is_same_v<_Dp, decay_t<_Up>> && is_floating_point_v<_Dp> 44*4bdff4beSrobert _LIBCPP_HIDE_FROM_ABI static constexpr weak_ordering __go__fn45*4bdff4beSrobert __go(_Tp&& __t, _Up&& __u, __priority_tag<2>) noexcept 46*4bdff4beSrobert { 47*4bdff4beSrobert partial_ordering __po = (__t <=> __u); 48*4bdff4beSrobert if (__po == partial_ordering::less) { 49*4bdff4beSrobert return weak_ordering::less; 50*4bdff4beSrobert } else if (__po == partial_ordering::equivalent) { 51*4bdff4beSrobert return weak_ordering::equivalent; 52*4bdff4beSrobert } else if (__po == partial_ordering::greater) { 53*4bdff4beSrobert return weak_ordering::greater; 54*4bdff4beSrobert } else { 55*4bdff4beSrobert // Otherwise, at least one of them is a NaN. 56*4bdff4beSrobert bool __t_is_nan = _VSTD::isnan(__t); 57*4bdff4beSrobert bool __u_is_nan = _VSTD::isnan(__u); 58*4bdff4beSrobert bool __t_is_negative = _VSTD::signbit(__t); 59*4bdff4beSrobert bool __u_is_negative = _VSTD::signbit(__u); 60*4bdff4beSrobert if (__t_is_nan && __u_is_nan) { 61*4bdff4beSrobert return (__u_is_negative <=> __t_is_negative); 62*4bdff4beSrobert } else if (__t_is_nan) { 63*4bdff4beSrobert return __t_is_negative ? weak_ordering::less : weak_ordering::greater; 64*4bdff4beSrobert } else { 65*4bdff4beSrobert return __u_is_negative ? weak_ordering::greater : weak_ordering::less; 66*4bdff4beSrobert } 67*4bdff4beSrobert } 68*4bdff4beSrobert } 69*4bdff4beSrobert 70*4bdff4beSrobert template<class _Tp, class _Up> 71*4bdff4beSrobert requires is_same_v<decay_t<_Tp>, decay_t<_Up>> 72*4bdff4beSrobert _LIBCPP_HIDE_FROM_ABI static constexpr auto 73*4bdff4beSrobert __go(_Tp&& __t, _Up&& __u, __priority_tag<1>) 74*4bdff4beSrobert noexcept(noexcept(weak_ordering(compare_three_way()(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))))) 75*4bdff4beSrobert -> decltype( weak_ordering(compare_three_way()(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u)))) 76*4bdff4beSrobert { return weak_ordering(compare_three_way()(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))); } 77*4bdff4beSrobert 78*4bdff4beSrobert template<class _Tp, class _Up> 79*4bdff4beSrobert requires is_same_v<decay_t<_Tp>, decay_t<_Up>> 80*4bdff4beSrobert _LIBCPP_HIDE_FROM_ABI static constexpr auto 81*4bdff4beSrobert __go(_Tp&& __t, _Up&& __u, __priority_tag<0>) 82*4bdff4beSrobert noexcept(noexcept(weak_ordering(_VSTD::strong_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))))) 83*4bdff4beSrobert -> decltype( weak_ordering(_VSTD::strong_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u)))) 84*4bdff4beSrobert { return weak_ordering(_VSTD::strong_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))); } 85*4bdff4beSrobert 86*4bdff4beSrobert template<class _Tp, class _Up> 87*4bdff4beSrobert _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp&& __t, _Up&& __u) const 88*4bdff4beSrobert noexcept(noexcept(__go(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u), __priority_tag<3>()))) 89*4bdff4beSrobert -> decltype( __go(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u), __priority_tag<3>())) 90*4bdff4beSrobert { return __go(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u), __priority_tag<3>()); } 91*4bdff4beSrobert }; 92*4bdff4beSrobert } // namespace __weak_order 93*4bdff4beSrobert 94*4bdff4beSrobert inline namespace __cpo { 95*4bdff4beSrobert inline constexpr auto weak_order = __weak_order::__fn{}; 96*4bdff4beSrobert } // namespace __cpo 97*4bdff4beSrobert 98*4bdff4beSrobert #endif // _LIBCPP_STD_VER > 17 99*4bdff4beSrobert 100*4bdff4beSrobert _LIBCPP_END_NAMESPACE_STD 101*4bdff4beSrobert 102*4bdff4beSrobert #endif // _LIBCPP___COMPARE_WEAK_ORDER 103