1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef _LIBCPP___COMPARE_PARTIAL_ORDER 10 #define _LIBCPP___COMPARE_PARTIAL_ORDER 11 12 #include <__compare/compare_three_way.h> 13 #include <__compare/ordering.h> 14 #include <__compare/weak_order.h> 15 #include <__config> 16 #include <__utility/forward.h> 17 #include <__utility/priority_tag.h> 18 #include <type_traits> 19 20 #ifndef _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER 21 # pragma GCC system_header 22 #endif 23 24 _LIBCPP_BEGIN_NAMESPACE_STD 25 26 #if _LIBCPP_STD_VER > 17 27 28 // [cmp.alg] 29 namespace __partial_order { 30 struct __fn { 31 template<class _Tp, class _Up> 32 requires is_same_v<decay_t<_Tp>, decay_t<_Up>> 33 _LIBCPP_HIDE_FROM_ABI static constexpr auto 34 __go(_Tp&& __t, _Up&& __u, __priority_tag<2>) 35 noexcept(noexcept(partial_ordering(partial_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))))) 36 -> decltype( partial_ordering(partial_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u)))) 37 { return partial_ordering(partial_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))); } 38 39 template<class _Tp, class _Up> 40 requires is_same_v<decay_t<_Tp>, decay_t<_Up>> 41 _LIBCPP_HIDE_FROM_ABI static constexpr auto 42 __go(_Tp&& __t, _Up&& __u, __priority_tag<1>) 43 noexcept(noexcept(partial_ordering(compare_three_way()(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))))) 44 -> decltype( partial_ordering(compare_three_way()(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u)))) 45 { return partial_ordering(compare_three_way()(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))); } 46 47 template<class _Tp, class _Up> 48 requires is_same_v<decay_t<_Tp>, decay_t<_Up>> 49 _LIBCPP_HIDE_FROM_ABI static constexpr auto 50 __go(_Tp&& __t, _Up&& __u, __priority_tag<0>) 51 noexcept(noexcept(partial_ordering(_VSTD::weak_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))))) 52 -> decltype( partial_ordering(_VSTD::weak_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u)))) 53 { return partial_ordering(_VSTD::weak_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))); } 54 55 template<class _Tp, class _Up> 56 _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp&& __t, _Up&& __u) const 57 noexcept(noexcept(__go(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u), __priority_tag<2>()))) 58 -> decltype( __go(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u), __priority_tag<2>())) 59 { return __go(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u), __priority_tag<2>()); } 60 }; 61 } // namespace __partial_order 62 63 inline namespace __cpo { 64 inline constexpr auto partial_order = __partial_order::__fn{}; 65 } // namespace __cpo 66 67 #endif // _LIBCPP_STD_VER > 17 68 69 _LIBCPP_END_NAMESPACE_STD 70 71 #endif // _LIBCPP___COMPARE_PARTIAL_ORDER 72