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_EQUAL_RANGE_H 10 #define _LIBCPP___ALGORITHM_EQUAL_RANGE_H 11 12 #include <__algorithm/comp.h> 13 #include <__algorithm/comp_ref_type.h> 14 #include <__algorithm/half_positive.h> 15 #include <__algorithm/iterator_operations.h> 16 #include <__algorithm/lower_bound.h> 17 #include <__algorithm/upper_bound.h> 18 #include <__config> 19 #include <__functional/identity.h> 20 #include <__iterator/advance.h> 21 #include <__iterator/distance.h> 22 #include <__iterator/iterator_traits.h> 23 #include <__utility/pair.h> 24 25 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 26 # pragma GCC system_header 27 #endif 28 29 _LIBCPP_BEGIN_NAMESPACE_STD 30 31 template <class _Compare, class _ForwardIterator, class _Tp> 32 _LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_ForwardIterator, _ForwardIterator> 33 __equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value, _Compare __comp) 34 { 35 typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type; 36 difference_type __len = _VSTD::distance(__first, __last); 37 while (__len != 0) 38 { 39 difference_type __l2 = _VSTD::__half_positive(__len); 40 _ForwardIterator __m = __first; 41 _VSTD::advance(__m, __l2); 42 if (__comp(*__m, __value)) 43 { 44 __first = ++__m; 45 __len -= __l2 + 1; 46 } 47 else if (__comp(__value, *__m)) 48 { 49 __last = __m; 50 __len = __l2; 51 } 52 else 53 { 54 auto __proj = std::__identity(); 55 _ForwardIterator __mp1 = __m; 56 return pair<_ForwardIterator, _ForwardIterator> 57 ( 58 _VSTD::__lower_bound_impl<_ClassicAlgPolicy>(__first, __m, __value, __comp, __proj), 59 _VSTD::__upper_bound<_Compare>(++__mp1, __last, __value, __comp) 60 ); 61 } 62 } 63 return pair<_ForwardIterator, _ForwardIterator>(__first, __first); 64 } 65 66 template <class _ForwardIterator, class _Tp, class _Compare> 67 _LIBCPP_NODISCARD_EXT inline 68 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 69 pair<_ForwardIterator, _ForwardIterator> 70 equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value, _Compare __comp) 71 { 72 typedef typename __comp_ref_type<_Compare>::type _Comp_ref; 73 return _VSTD::__equal_range<_Comp_ref>(__first, __last, __value, __comp); 74 } 75 76 template <class _ForwardIterator, class _Tp> 77 _LIBCPP_NODISCARD_EXT inline 78 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 79 pair<_ForwardIterator, _ForwardIterator> 80 equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) 81 { 82 return _VSTD::equal_range(__first, __last, __value, 83 __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>()); 84 } 85 86 _LIBCPP_END_NAMESPACE_STD 87 88 #endif // _LIBCPP___ALGORITHM_EQUAL_RANGE_H 89