| //===----------------------------------------------------------------------===// |
| // |
| // 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___ALGORITHM_THREE_WAY_COMP_REF_TYPE_H |
| #define _LIBCPP___ALGORITHM_THREE_WAY_COMP_REF_TYPE_H |
| |
| #include <__compare/ordering.h> |
| #include <__config> |
| #include <__debug> |
| #include <__utility/declval.h> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| #if _LIBCPP_STD_VER >= 20 |
| |
| template <class _Comp> |
| struct __debug_three_way_comp { |
| _Comp& __comp_; |
| _LIBCPP_HIDE_FROM_ABI constexpr __debug_three_way_comp(_Comp& __c) : __comp_(__c) {} |
| |
| template <class _Tp, class _Up> |
| _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp& __x, _Up& __y) { |
| auto __r = __comp_(__x, __y); |
| __do_compare_assert(0, __y, __x, __r); |
| return __r; |
| } |
| |
| template <class _LHS, class _RHS, class _Order> |
| _LIBCPP_HIDE_FROM_ABI constexpr inline void __do_compare_assert(int, _LHS& __l, _RHS& __r, _Order __o) |
| requires __comparison_category<decltype(std::declval<_Comp&>()(std::declval<_LHS&>(), std::declval<_RHS&>()))> |
| { |
| _Order __expected = __o; |
| if (__o == _Order::less) |
| __expected = _Order::greater; |
| if (__o == _Order::greater) |
| __expected = _Order::less; |
| _LIBCPP_DEBUG_ASSERT(__comp_(__l, __r) == __expected, "Comparator does not induce a strict weak ordering"); |
| (void)__l; |
| (void)__r; |
| (void)__expected; |
| } |
| |
| template <class _LHS, class _RHS, class _Order> |
| _LIBCPP_HIDE_FROM_ABI constexpr inline void __do_compare_assert(long, _LHS&, _RHS&, _Order) {} |
| }; |
| |
| // Pass the comparator by lvalue reference. Or in debug mode, using a |
| // debugging wrapper that stores a reference. |
| # ifndef _LIBCPP_ENABLE_DEBUG_MODE |
| template <class _Comp> |
| using __three_way_comp_ref_type = __debug_three_way_comp<_Comp>; |
| # else |
| template <class _Comp> |
| using __three_way_comp_ref_type = _Comp&; |
| # endif |
| |
| #endif // _LIBCPP_STD_VER >= 20 |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___ALGORITHM_THREE_WAY_COMP_REF_TYPE_H |