//===----------------------------------------------------------------------===// // // 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_MINMAX_ELEMENT_H #define _LIBCPP___ALGORITHM_MINMAX_ELEMENT_H #include <__algorithm/comp.h> #include <__config> #include <__functional/identity.h> #include <__functional/invoke.h> #include <__iterator/iterator_traits.h> #include <__type_traits/is_callable.h> #include <__utility/pair.h> #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) # pragma GCC system_header #endif _LIBCPP_BEGIN_NAMESPACE_STD template class _MinmaxElementLessFunc { _Comp& __comp_; _Proj& __proj_; public: _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _MinmaxElementLessFunc(_Comp& __comp, _Proj& __proj) : __comp_(__comp), __proj_(__proj) {} template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool operator()(_Iter& __it1, _Iter& __it2) { return std::__invoke(__comp_, std::__invoke(__proj_, *__it1), std::__invoke(__proj_, *__it2)); } }; template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_Iter, _Iter> __minmax_element_impl(_Iter __first, _Sent __last, _Comp& __comp, _Proj& __proj) { auto __less = _MinmaxElementLessFunc<_Comp, _Proj>(__comp, __proj); pair<_Iter, _Iter> __result(__first, __first); if (__first == __last || ++__first == __last) return __result; if (__less(__first, __result.first)) __result.first = __first; else __result.second = __first; while (++__first != __last) { _Iter __i = __first; if (++__first == __last) { if (__less(__i, __result.first)) __result.first = __i; else if (!__less(__i, __result.second)) __result.second = __i; return __result; } if (__less(__first, __i)) { if (__less(__first, __result.first)) __result.first = __first; if (!__less(__i, __result.second)) __result.second = __i; } else { if (__less(__i, __result.first)) __result.first = __i; if (!__less(__first, __result.second)) __result.second = __first; } } return __result; } template _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_ForwardIterator, _ForwardIterator> minmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp) { static_assert( __has_forward_iterator_category<_ForwardIterator>::value, "std::minmax_element requires a ForwardIterator"); static_assert( __is_callable<_Compare, decltype(*__first), decltype(*__first)>::value, "The comparator has to be callable"); auto __proj = __identity(); return std::__minmax_element_impl(__first, __last, __comp, __proj); } template _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_ForwardIterator, _ForwardIterator> minmax_element(_ForwardIterator __first, _ForwardIterator __last) { return std::minmax_element(__first, __last, __less<>()); } _LIBCPP_END_NAMESPACE_STD #endif // _LIBCPP___ALGORITHM_MINMAX_ELEMENT_H