1fe6060f1SDimitry Andric //===----------------------------------------------------------------------===// 2fe6060f1SDimitry Andric // 3fe6060f1SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4fe6060f1SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 5fe6060f1SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6fe6060f1SDimitry Andric // 7fe6060f1SDimitry Andric //===----------------------------------------------------------------------===// 8fe6060f1SDimitry Andric 9fe6060f1SDimitry Andric #ifndef _LIBCPP___ALGORITHM_MINMAX_ELEMENT_H 10fe6060f1SDimitry Andric #define _LIBCPP___ALGORITHM_MINMAX_ELEMENT_H 11fe6060f1SDimitry Andric 12fe6060f1SDimitry Andric #include <__algorithm/comp.h> 1304eeddc0SDimitry Andric #include <__config> 1481ad6265SDimitry Andric #include <__functional/identity.h> 1506c3fb27SDimitry Andric #include <__functional/invoke.h> 16fe6060f1SDimitry Andric #include <__iterator/iterator_traits.h> 1706c3fb27SDimitry Andric #include <__type_traits/is_callable.h> 1881ad6265SDimitry Andric #include <__utility/pair.h> 19fe6060f1SDimitry Andric 20fe6060f1SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 21fe6060f1SDimitry Andric # pragma GCC system_header 22fe6060f1SDimitry Andric #endif 23fe6060f1SDimitry Andric 24fe6060f1SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD 25fe6060f1SDimitry Andric 2681ad6265SDimitry Andric template <class _Comp, class _Proj> 2781ad6265SDimitry Andric class _MinmaxElementLessFunc { 28753f127fSDimitry Andric _Comp& __comp_; 29753f127fSDimitry Andric _Proj& __proj_; 3081ad6265SDimitry Andric 3181ad6265SDimitry Andric public: 32cb14a3feSDimitry Andric _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _MinmaxElementLessFunc(_Comp& __comp, _Proj& __proj) 33cb14a3feSDimitry Andric : __comp_(__comp), __proj_(__proj) {} 3481ad6265SDimitry Andric 3581ad6265SDimitry Andric template <class _Iter> 36cb14a3feSDimitry Andric _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool operator()(_Iter& __it1, _Iter& __it2) { 37753f127fSDimitry Andric return std::__invoke(__comp_, std::__invoke(__proj_, *__it1), std::__invoke(__proj_, *__it2)); 3881ad6265SDimitry Andric } 3981ad6265SDimitry Andric }; 4081ad6265SDimitry Andric 4181ad6265SDimitry Andric template <class _Iter, class _Sent, class _Proj, class _Comp> 42cb14a3feSDimitry Andric _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_Iter, _Iter> 43cb14a3feSDimitry Andric __minmax_element_impl(_Iter __first, _Sent __last, _Comp& __comp, _Proj& __proj) { 4481ad6265SDimitry Andric auto __less = _MinmaxElementLessFunc<_Comp, _Proj>(__comp, __proj); 4581ad6265SDimitry Andric 4681ad6265SDimitry Andric pair<_Iter, _Iter> __result(__first, __first); 4781ad6265SDimitry Andric if (__first == __last || ++__first == __last) 4881ad6265SDimitry Andric return __result; 4981ad6265SDimitry Andric 5081ad6265SDimitry Andric if (__less(__first, __result.first)) 51fe6060f1SDimitry Andric __result.first = __first; 52fe6060f1SDimitry Andric else 53fe6060f1SDimitry Andric __result.second = __first; 5481ad6265SDimitry Andric 5581ad6265SDimitry Andric while (++__first != __last) { 5681ad6265SDimitry Andric _Iter __i = __first; 5781ad6265SDimitry Andric if (++__first == __last) { 5881ad6265SDimitry Andric if (__less(__i, __result.first)) 59fe6060f1SDimitry Andric __result.first = __i; 6081ad6265SDimitry Andric else if (!__less(__i, __result.second)) 61fe6060f1SDimitry Andric __result.second = __i; 62fe6060f1SDimitry Andric return __result; 63fe6060f1SDimitry Andric } 64fe6060f1SDimitry Andric 6581ad6265SDimitry Andric if (__less(__first, __i)) { 6681ad6265SDimitry Andric if (__less(__first, __result.first)) 6781ad6265SDimitry Andric __result.first = __first; 6881ad6265SDimitry Andric if (!__less(__i, __result.second)) 6981ad6265SDimitry Andric __result.second = __i; 7081ad6265SDimitry Andric } else { 7181ad6265SDimitry Andric if (__less(__i, __result.first)) 7281ad6265SDimitry Andric __result.first = __i; 7381ad6265SDimitry Andric if (!__less(__first, __result.second)) 7481ad6265SDimitry Andric __result.second = __first; 7581ad6265SDimitry Andric } 7681ad6265SDimitry Andric } 7781ad6265SDimitry Andric 7881ad6265SDimitry Andric return __result; 7981ad6265SDimitry Andric } 8081ad6265SDimitry Andric 8181ad6265SDimitry Andric template <class _ForwardIterator, class _Compare> 82*0fca6ea1SDimitry Andric _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_ForwardIterator, _ForwardIterator> 8381ad6265SDimitry Andric minmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp) { 84cb14a3feSDimitry Andric static_assert( 85cb14a3feSDimitry Andric __has_forward_iterator_category<_ForwardIterator>::value, "std::minmax_element requires a ForwardIterator"); 86cb14a3feSDimitry Andric static_assert( 87cb14a3feSDimitry Andric __is_callable<_Compare, decltype(*__first), decltype(*__first)>::value, "The comparator has to be callable"); 8881ad6265SDimitry Andric auto __proj = __identity(); 8981ad6265SDimitry Andric return std::__minmax_element_impl(__first, __last, __comp, __proj); 9081ad6265SDimitry Andric } 9181ad6265SDimitry Andric 9281ad6265SDimitry Andric template <class _ForwardIterator> 93*0fca6ea1SDimitry Andric _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_ForwardIterator, _ForwardIterator> 94cb14a3feSDimitry Andric minmax_element(_ForwardIterator __first, _ForwardIterator __last) { 9506c3fb27SDimitry Andric return std::minmax_element(__first, __last, __less<>()); 96fe6060f1SDimitry Andric } 97fe6060f1SDimitry Andric 98fe6060f1SDimitry Andric _LIBCPP_END_NAMESPACE_STD 99fe6060f1SDimitry Andric 100fe6060f1SDimitry Andric #endif // _LIBCPP___ALGORITHM_MINMAX_ELEMENT_H 101