1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef _LIBCPP___ALGORITHM_MINMAX_ELEMENT_H 10 #define _LIBCPP___ALGORITHM_MINMAX_ELEMENT_H 11 12 #include <__config> 13 #include <__algorithm/comp.h> 14 #include <__iterator/iterator_traits.h> 15 #include <utility> 16 17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 18 #pragma GCC system_header 19 #endif 20 21 _LIBCPP_PUSH_MACROS 22 #include <__undef_macros> 23 24 _LIBCPP_BEGIN_NAMESPACE_STD 25 26 template <class _ForwardIterator, class _Compare> 27 _LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX11 28 pair<_ForwardIterator, _ForwardIterator> 29 minmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp) 30 { 31 static_assert(__is_cpp17_forward_iterator<_ForwardIterator>::value, 32 "std::minmax_element requires a ForwardIterator"); 33 pair<_ForwardIterator, _ForwardIterator> __result(__first, __first); 34 if (__first != __last) 35 { 36 if (++__first != __last) 37 { 38 if (__comp(*__first, *__result.first)) 39 __result.first = __first; 40 else 41 __result.second = __first; 42 while (++__first != __last) 43 { 44 _ForwardIterator __i = __first; 45 if (++__first == __last) 46 { 47 if (__comp(*__i, *__result.first)) 48 __result.first = __i; 49 else if (!__comp(*__i, *__result.second)) 50 __result.second = __i; 51 break; 52 } 53 else 54 { 55 if (__comp(*__first, *__i)) 56 { 57 if (__comp(*__first, *__result.first)) 58 __result.first = __first; 59 if (!__comp(*__i, *__result.second)) 60 __result.second = __i; 61 } 62 else 63 { 64 if (__comp(*__i, *__result.first)) 65 __result.first = __i; 66 if (!__comp(*__first, *__result.second)) 67 __result.second = __first; 68 } 69 } 70 } 71 } 72 } 73 return __result; 74 } 75 76 template <class _ForwardIterator> 77 _LIBCPP_NODISCARD_EXT inline 78 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 79 pair<_ForwardIterator, _ForwardIterator> 80 minmax_element(_ForwardIterator __first, _ForwardIterator __last) 81 { 82 return _VSTD::minmax_element(__first, __last, 83 __less<typename iterator_traits<_ForwardIterator>::value_type>()); 84 } 85 86 _LIBCPP_END_NAMESPACE_STD 87 88 _LIBCPP_POP_MACROS 89 90 #endif // _LIBCPP___ALGORITHM_MINMAX_ELEMENT_H 91