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