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