1349cc55cSDimitry Andric //===----------------------------------------------------------------------===// 2349cc55cSDimitry Andric // 3349cc55cSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4349cc55cSDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 5349cc55cSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6349cc55cSDimitry Andric // 7349cc55cSDimitry Andric //===----------------------------------------------------------------------===// 8349cc55cSDimitry Andric 9349cc55cSDimitry Andric #ifndef _LIBCPP___COMPARE_COMPARE_THREE_WAY_RESULT_H 10349cc55cSDimitry Andric #define _LIBCPP___COMPARE_COMPARE_THREE_WAY_RESULT_H 11349cc55cSDimitry Andric 12349cc55cSDimitry Andric #include <__config> 13bdd1243dSDimitry Andric #include <__type_traits/make_const_lvalue_ref.h> 14bdd1243dSDimitry Andric #include <__utility/declval.h> 15349cc55cSDimitry Andric 16349cc55cSDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 17349cc55cSDimitry Andric # pragma GCC system_header 18349cc55cSDimitry Andric #endif 19349cc55cSDimitry Andric 20349cc55cSDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD 21349cc55cSDimitry Andric 2206c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 20 23349cc55cSDimitry Andric 24349cc55cSDimitry Andric template <class, class, class> 25349cc55cSDimitry Andric struct _LIBCPP_HIDE_FROM_ABI __compare_three_way_result {}; 26349cc55cSDimitry Andric 27349cc55cSDimitry Andric template <class _Tp, class _Up> 28*cb14a3feSDimitry Andric struct _LIBCPP_HIDE_FROM_ABI __compare_three_way_result< 29*cb14a3feSDimitry Andric _Tp, 30*cb14a3feSDimitry Andric _Up, 31*cb14a3feSDimitry Andric decltype(std::declval<__make_const_lvalue_ref<_Tp>>() <=> std::declval<__make_const_lvalue_ref<_Up>>(), void())> { 32bdd1243dSDimitry Andric using type = decltype(std::declval<__make_const_lvalue_ref<_Tp>>() <=> std::declval<__make_const_lvalue_ref<_Up>>()); 33349cc55cSDimitry Andric }; 34349cc55cSDimitry Andric 35349cc55cSDimitry Andric template <class _Tp, class _Up = _Tp> 36349cc55cSDimitry Andric struct _LIBCPP_TEMPLATE_VIS compare_three_way_result : __compare_three_way_result<_Tp, _Up, void> {}; 37349cc55cSDimitry Andric 38349cc55cSDimitry Andric template <class _Tp, class _Up = _Tp> 39349cc55cSDimitry Andric using compare_three_way_result_t = typename compare_three_way_result<_Tp, _Up>::type; 40349cc55cSDimitry Andric 4106c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 20 42349cc55cSDimitry Andric 43349cc55cSDimitry Andric _LIBCPP_END_NAMESPACE_STD 44349cc55cSDimitry Andric 45349cc55cSDimitry Andric #endif // _LIBCPP___COMPARE_COMPARE_THREE_WAY_RESULT_H 46