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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 */
38template <class _Container, class _Iterator>
39struct __ra_iterator {
40private:
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
49public:
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
158

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source code of libcxx/include/__flat_set/ra_iterator.h