| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef _LIBCPP___COMPARE_WEAK_ORDER |
| #define _LIBCPP___COMPARE_WEAK_ORDER |
| |
| #include <__compare/compare_three_way.h> |
| #include <__compare/ordering.h> |
| #include <__compare/strong_order.h> |
| #include <__config> |
| #include <__utility/forward.h> |
| #include <__utility/priority_tag.h> |
| #include <cmath> |
| #include <type_traits> |
| |
| #ifndef _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER |
| #pragma GCC system_header |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| #if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) |
| |
| // [cmp.alg] |
| namespace __weak_order { |
| struct __fn { |
| template<class _Tp, class _Up> |
| requires is_same_v<decay_t<_Tp>, decay_t<_Up>> |
| _LIBCPP_HIDE_FROM_ABI static constexpr auto |
| __go(_Tp&& __t, _Up&& __u, __priority_tag<3>) |
| noexcept(noexcept(weak_ordering(weak_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))))) |
| -> decltype( weak_ordering(weak_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u)))) |
| { return weak_ordering(weak_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))); } |
| |
| template<class _Tp, class _Up, class _Dp = decay_t<_Tp>> |
| requires is_same_v<_Dp, decay_t<_Up>> && is_floating_point_v<_Dp> |
| _LIBCPP_HIDE_FROM_ABI static constexpr weak_ordering |
| __go(_Tp&& __t, _Up&& __u, __priority_tag<2>) noexcept |
| { |
| std::partial_ordering __po = (__t <=> __u); |
| if (__po == std::partial_ordering::less) { |
| return std::weak_ordering::less; |
| } else if (__po == std::partial_ordering::equivalent) { |
| return std::weak_ordering::equivalent; |
| } else if (__po == std::partial_ordering::greater) { |
| return std::weak_ordering::greater; |
| } else { |
| // Otherwise, at least one of them is a NaN. |
| bool __t_is_nan = _VSTD::isnan(__t); |
| bool __u_is_nan = _VSTD::isnan(__u); |
| bool __t_is_negative = _VSTD::signbit(__t); |
| bool __u_is_negative = _VSTD::signbit(__u); |
| if (__t_is_nan && __u_is_nan) { |
| return (__u_is_negative <=> __t_is_negative); |
| } else if (__t_is_nan) { |
| return __t_is_negative ? weak_ordering::less : weak_ordering::greater; |
| } else { |
| return __u_is_negative ? weak_ordering::greater : weak_ordering::less; |
| } |
| } |
| } |
| |
| template<class _Tp, class _Up> |
| requires is_same_v<decay_t<_Tp>, decay_t<_Up>> |
| _LIBCPP_HIDE_FROM_ABI static constexpr auto |
| __go(_Tp&& __t, _Up&& __u, __priority_tag<1>) |
| noexcept(noexcept(weak_ordering(compare_three_way()(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))))) |
| -> decltype( weak_ordering(compare_three_way()(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u)))) |
| { return weak_ordering(compare_three_way()(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))); } |
| |
| template<class _Tp, class _Up> |
| requires is_same_v<decay_t<_Tp>, decay_t<_Up>> |
| _LIBCPP_HIDE_FROM_ABI static constexpr auto |
| __go(_Tp&& __t, _Up&& __u, __priority_tag<0>) |
| noexcept(noexcept(weak_ordering(_VSTD::strong_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))))) |
| -> decltype( weak_ordering(_VSTD::strong_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u)))) |
| { return weak_ordering(_VSTD::strong_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))); } |
| |
| template<class _Tp, class _Up> |
| _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp&& __t, _Up&& __u) const |
| noexcept(noexcept(__go(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u), __priority_tag<3>()))) |
| -> decltype( __go(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u), __priority_tag<3>())) |
| { return __go(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u), __priority_tag<3>()); } |
| }; |
| } // namespace __weak_order |
| |
| inline namespace __cpo { |
| inline constexpr auto weak_order = __weak_order::__fn{}; |
| } // namespace __cpo |
| |
| #endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___COMPARE_WEAK_ORDER |
