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 <__functional/invoke.h> 21 #include <__iterator/advance.h> 22 #include <__iterator/distance.h> 23 #include <__iterator/iterator_traits.h> 24 #include <__iterator/next.h> 25 #include <__type_traits/is_callable.h> 26 #include <__type_traits/is_copy_constructible.h> 27 #include <__utility/move.h> 28 #include <__utility/pair.h> 29 30 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 31 # pragma GCC system_header 32 #endif 33 34 _LIBCPP_PUSH_MACROS 35 #include <__undef_macros> 36 37 _LIBCPP_BEGIN_NAMESPACE_STD 38 39 template <class _AlgPolicy, class _Compare, class _Iter, class _Sent, class _Tp, class _Proj> 40 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_Iter, _Iter> 41 __equal_range(_Iter __first, _Sent __last, const _Tp& __value, _Compare&& __comp, _Proj&& __proj) { 42 auto __len = _IterOps<_AlgPolicy>::distance(__first, __last); 43 _Iter __end = _IterOps<_AlgPolicy>::next(__first, __last); 44 while (__len != 0) { 45 auto __half_len = std::__half_positive(__len); 46 _Iter __mid = _IterOps<_AlgPolicy>::next(__first, __half_len); 47 if (std::__invoke(__comp, std::__invoke(__proj, *__mid), __value)) { 48 __first = ++__mid; 49 __len -= __half_len + 1; 50 } else if (std::__invoke(__comp, __value, std::__invoke(__proj, *__mid))) { 51 __end = __mid; 52 __len = __half_len; 53 } else { 54 _Iter __mp1 = __mid; 55 return pair<_Iter, _Iter>(std::__lower_bound<_AlgPolicy>(__first, __mid, __value, __comp, __proj), 56 std::__upper_bound<_AlgPolicy>(++__mp1, __end, __value, __comp, __proj)); 57 } 58 } 59 return pair<_Iter, _Iter>(__first, __first); 60 } 61 62 template <class _ForwardIterator, class _Tp, class _Compare> 63 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_ForwardIterator, _ForwardIterator> 64 equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value, _Compare __comp) { 65 static_assert(__is_callable<_Compare, decltype(*__first), const _Tp&>::value, "The comparator has to be callable"); 66 static_assert(is_copy_constructible<_ForwardIterator>::value, "Iterator has to be copy constructible"); 67 return std::__equal_range<_ClassicAlgPolicy>( 68 std::move(__first), 69 std::move(__last), 70 __value, 71 static_cast<__comp_ref_type<_Compare> >(__comp), 72 std::__identity()); 73 } 74 75 template <class _ForwardIterator, class _Tp> 76 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_ForwardIterator, _ForwardIterator> 77 equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) { 78 return std::equal_range(std::move(__first), std::move(__last), __value, __less<>()); 79 } 80 81 _LIBCPP_END_NAMESPACE_STD 82 83 _LIBCPP_POP_MACROS 84 85 #endif // _LIBCPP___ALGORITHM_EQUAL_RANGE_H 86