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| 1 | +// -*- C++ -*- |
| 2 | +//===----------------------------------------------------------------------===// |
| 3 | +// |
| 4 | +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 5 | +// See https://llvm.org/LICENSE.txt for license information. |
| 6 | +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 7 | +// |
| 8 | +//===----------------------------------------------------------------------===// |
| 9 | + |
| 10 | +#ifndef _LIBCPP___FLAT_SET_RA_ITERATOR_H |
| 11 | +#define _LIBCPP___FLAT_SET_RA_ITERATOR_H |
| 12 | + |
| 13 | +#include "__type_traits/is_same.h" |
| 14 | +#include <__compare/three_way_comparable.h> |
| 15 | +#include <__config> |
| 16 | +#include <__iterator/incrementable_traits.h> |
| 17 | +#include <__iterator/iterator_traits.h> |
| 18 | +#include <__type_traits/is_constructible.h> |
| 19 | +#include <__utility/move.h> |
| 20 | + |
| 21 | +#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| 22 | +# pragma GCC system_header |
| 23 | +#endif |
| 24 | + |
| 25 | +_LIBCPP_PUSH_MACROS |
| 26 | +#include <__undef_macros> |
| 27 | + |
| 28 | +#if _LIBCPP_STD_VER >= 23 |
| 29 | + |
| 30 | +_LIBCPP_BEGIN_NAMESPACE_STD |
| 31 | + |
| 32 | +/** |
| 33 | + * __ra_iterator is a random access iterator that wraps an underlying iterator. |
| 34 | + * It also stores the underlying container type in its type so that algorithms |
| 35 | + * can optimize based on the underlying container type, and to avoid inadvertently |
| 36 | + * mixing iterators coming from different containers.. |
| 37 | + */ |
| 38 | +template <class _Container, class _Iterator> |
| 39 | +struct __ra_iterator { |
| 40 | +private: |
| 41 | + _Iterator __iter_; |
| 42 | + |
| 43 | + friend _Container; |
| 44 | + |
| 45 | + // note: checking the concept random_access_iterator does not work for incomplete types |
| 46 | + static_assert(_IsSame<typename iterator_traits<_Iterator>::iterator_category, random_access_iterator_tag>::value, |
| 47 | + "Underlying iterator must be a random access iterator"); |
| 48 | + |
| 49 | +public: |
| 50 | + using iterator_concept = random_access_iterator_tag; // deliberately lower contiguous_iterator |
| 51 | + using iterator_category = random_access_iterator_tag; |
| 52 | + using value_type = iter_value_t<_Iterator>; |
| 53 | + using difference_type = iter_difference_t<_Iterator>; |
| 54 | + |
| 55 | + _LIBCPP_HIDE_FROM_ABI __ra_iterator() |
| 56 | + requires is_default_constructible_v<_Iterator> |
| 57 | + = default; |
| 58 | + |
| 59 | + _LIBCPP_HIDE_FROM_ABI explicit constexpr __ra_iterator(_Iterator __iter) : __iter_(std::move(__iter)) {} |
| 60 | + |
| 61 | + _LIBCPP_HIDE_FROM_ABI constexpr _Iterator __base() const noexcept(noexcept(_Iterator(__iter_))) { return __iter_; } |
| 62 | + |
| 63 | + _LIBCPP_HIDE_FROM_ABI constexpr decltype(auto) operator*() const { return *__iter_; } |
| 64 | + _LIBCPP_HIDE_FROM_ABI constexpr decltype(auto) operator->() const |
| 65 | + requires requires { __iter_.operator->(); } |
| 66 | + { |
| 67 | + return __iter_.operator->(); |
| 68 | + } |
| 69 | + |
| 70 | + _LIBCPP_HIDE_FROM_ABI constexpr __ra_iterator& operator++() { |
| 71 | + ++__iter_; |
| 72 | + return *this; |
| 73 | + } |
| 74 | + |
| 75 | + _LIBCPP_HIDE_FROM_ABI constexpr __ra_iterator operator++(int) { |
| 76 | + __ra_iterator __tmp(*this); |
| 77 | + ++*this; |
| 78 | + return __tmp; |
| 79 | + } |
| 80 | + |
| 81 | + _LIBCPP_HIDE_FROM_ABI constexpr __ra_iterator& operator--() { |
| 82 | + --__iter_; |
| 83 | + return *this; |
| 84 | + } |
| 85 | + |
| 86 | + _LIBCPP_HIDE_FROM_ABI constexpr __ra_iterator operator--(int) { |
| 87 | + __ra_iterator __tmp(*this); |
| 88 | + --*this; |
| 89 | + return __tmp; |
| 90 | + } |
| 91 | + |
| 92 | + _LIBCPP_HIDE_FROM_ABI constexpr __ra_iterator& operator+=(difference_type __x) { |
| 93 | + __iter_ += __x; |
| 94 | + return *this; |
| 95 | + } |
| 96 | + |
| 97 | + _LIBCPP_HIDE_FROM_ABI constexpr __ra_iterator& operator-=(difference_type __x) { |
| 98 | + __iter_ -= __x; |
| 99 | + return *this; |
| 100 | + } |
| 101 | + |
| 102 | + _LIBCPP_HIDE_FROM_ABI constexpr decltype(auto) operator[](difference_type __n) const { return *(*this + __n); } |
| 103 | + |
| 104 | + _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const __ra_iterator& __x, const __ra_iterator& __y) { |
| 105 | + return __x.__iter_ == __y.__iter_; |
| 106 | + } |
| 107 | + |
| 108 | + _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator<(const __ra_iterator& __x, const __ra_iterator& __y) { |
| 109 | + return __x.__iter_ < __y.__iter_; |
| 110 | + } |
| 111 | + |
| 112 | + _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator>(const __ra_iterator& __x, const __ra_iterator& __y) { |
| 113 | + return __y < __x; |
| 114 | + } |
| 115 | + |
| 116 | + _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator<=(const __ra_iterator& __x, const __ra_iterator& __y) { |
| 117 | + return !(__y < __x); |
| 118 | + } |
| 119 | + |
| 120 | + _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator>=(const __ra_iterator& __x, const __ra_iterator& __y) { |
| 121 | + return !(__x < __y); |
| 122 | + } |
| 123 | + |
| 124 | + _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator<=>(const __ra_iterator& __x, const __ra_iterator& __y) |
| 125 | + requires three_way_comparable<_Iterator> |
| 126 | + { |
| 127 | + return __x.__iter_ <=> __y.__iter_; |
| 128 | + } |
| 129 | + |
| 130 | + _LIBCPP_HIDE_FROM_ABI friend constexpr __ra_iterator operator+(const __ra_iterator& __i, difference_type __n) { |
| 131 | + auto __tmp = __i; |
| 132 | + __tmp += __n; |
| 133 | + return __tmp; |
| 134 | + } |
| 135 | + |
| 136 | + _LIBCPP_HIDE_FROM_ABI friend constexpr __ra_iterator operator+(difference_type __n, const __ra_iterator& __i) { |
| 137 | + return __i + __n; |
| 138 | + } |
| 139 | + |
| 140 | + _LIBCPP_HIDE_FROM_ABI friend constexpr __ra_iterator operator-(const __ra_iterator& __i, difference_type __n) { |
| 141 | + auto __tmp = __i; |
| 142 | + __tmp -= __n; |
| 143 | + return __tmp; |
| 144 | + } |
| 145 | + |
| 146 | + _LIBCPP_HIDE_FROM_ABI friend constexpr difference_type operator-(const __ra_iterator& __x, const __ra_iterator& __y) { |
| 147 | + return __x.__iter_ - __y.__iter_; |
| 148 | + } |
| 149 | +}; |
| 150 | + |
| 151 | +_LIBCPP_END_NAMESPACE_STD |
| 152 | + |
| 153 | +#endif // _LIBCPP_STD_VER >= 23 |
| 154 | + |
| 155 | +_LIBCPP_POP_MACROS |
| 156 | + |
| 157 | +#endif // _LIBCPP___FLAT_SET_RA_ITERATOR_H |
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