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_COMPARE_STRONG_ORDER_FALLBACK 10#define _LIBCPP___COMPARE_COMPARE_STRONG_ORDER_FALLBACK 11 12#include <__compare/ordering.h> 13#include <__compare/strong_order.h> 14#include <__config> 15#include <__type_traits/decay.h> 16#include <__type_traits/is_same.h> 17#include <__utility/forward.h> 18#include <__utility/priority_tag.h> 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] 29namespace __compare_strong_order_fallback { 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<1>) 35 noexcept(noexcept(_VSTD::strong_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u)))) 36 -> decltype( _VSTD::strong_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))) 37 { return _VSTD::strong_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<0>) 43 noexcept(noexcept(_VSTD::forward<_Tp>(__t) == _VSTD::forward<_Up>(__u) ? strong_ordering::equal : 44 _VSTD::forward<_Tp>(__t) < _VSTD::forward<_Up>(__u) ? strong_ordering::less : 45 strong_ordering::greater)) 46 -> decltype( _VSTD::forward<_Tp>(__t) == _VSTD::forward<_Up>(__u) ? strong_ordering::equal : 47 _VSTD::forward<_Tp>(__t) < _VSTD::forward<_Up>(__u) ? strong_ordering::less : 48 strong_ordering::greater) 49 { 50 return _VSTD::forward<_Tp>(__t) == _VSTD::forward<_Up>(__u) ? strong_ordering::equal : 51 _VSTD::forward<_Tp>(__t) < _VSTD::forward<_Up>(__u) ? strong_ordering::less : 52 strong_ordering::greater; 53 } 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<1>()))) 58 -> decltype( __go(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u), __priority_tag<1>())) 59 { return __go(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u), __priority_tag<1>()); } 60 }; 61} // namespace __compare_strong_order_fallback 62 63inline namespace __cpo { 64 inline constexpr auto compare_strong_order_fallback = __compare_strong_order_fallback::__fn{}; 65} // namespace __cpo 66 67#endif // _LIBCPP_STD_VER > 17 68 69_LIBCPP_END_NAMESPACE_STD 70 71#endif // _LIBCPP___COMPARE_COMPARE_STRONG_ORDER_FALLBACK 72