xref: /freebsd/contrib/llvm-project/libcxx/include/__iterator/wrap_iter.h (revision 1db9f3b21e39176dd5b67cf8ac378633b172463e)
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___ITERATOR_WRAP_ITER_H
11 #define _LIBCPP___ITERATOR_WRAP_ITER_H
12 
13 #include <__config>
14 #include <__iterator/iterator_traits.h>
15 #include <__memory/addressof.h>
16 #include <__memory/pointer_traits.h>
17 #include <__type_traits/enable_if.h>
18 #include <__type_traits/is_convertible.h>
19 #include <cstddef>
20 
21 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
22 #  pragma GCC system_header
23 #endif
24 
25 _LIBCPP_BEGIN_NAMESPACE_STD
26 
27 template <class _Iter>
28 class __wrap_iter {
29 public:
30   typedef _Iter iterator_type;
31   typedef typename iterator_traits<iterator_type>::value_type value_type;
32   typedef typename iterator_traits<iterator_type>::difference_type difference_type;
33   typedef typename iterator_traits<iterator_type>::pointer pointer;
34   typedef typename iterator_traits<iterator_type>::reference reference;
35   typedef typename iterator_traits<iterator_type>::iterator_category iterator_category;
36 #if _LIBCPP_STD_VER >= 20
37   typedef contiguous_iterator_tag iterator_concept;
38 #endif
39 
40 private:
41   iterator_type __i_;
42 
43 public:
44   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 __wrap_iter() _NOEXCEPT : __i_() {}
45   template <class _Up, __enable_if_t<is_convertible<_Up, iterator_type>::value, int> = 0>
46   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 __wrap_iter(const __wrap_iter<_Up>& __u) _NOEXCEPT
47       : __i_(__u.base()) {}
48   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 reference operator*() const _NOEXCEPT { return *__i_; }
49   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pointer operator->() const _NOEXCEPT {
50     return std::__to_address(__i_);
51   }
52   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 __wrap_iter& operator++() _NOEXCEPT {
53     ++__i_;
54     return *this;
55   }
56   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 __wrap_iter operator++(int) _NOEXCEPT {
57     __wrap_iter __tmp(*this);
58     ++(*this);
59     return __tmp;
60   }
61 
62   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 __wrap_iter& operator--() _NOEXCEPT {
63     --__i_;
64     return *this;
65   }
66   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 __wrap_iter operator--(int) _NOEXCEPT {
67     __wrap_iter __tmp(*this);
68     --(*this);
69     return __tmp;
70   }
71   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 __wrap_iter operator+(difference_type __n) const _NOEXCEPT {
72     __wrap_iter __w(*this);
73     __w += __n;
74     return __w;
75   }
76   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 __wrap_iter& operator+=(difference_type __n) _NOEXCEPT {
77     __i_ += __n;
78     return *this;
79   }
80   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 __wrap_iter operator-(difference_type __n) const _NOEXCEPT {
81     return *this + (-__n);
82   }
83   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 __wrap_iter& operator-=(difference_type __n) _NOEXCEPT {
84     *this += -__n;
85     return *this;
86   }
87   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 reference operator[](difference_type __n) const _NOEXCEPT {
88     return __i_[__n];
89   }
90 
91   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 iterator_type base() const _NOEXCEPT { return __i_; }
92 
93 private:
94   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit __wrap_iter(iterator_type __x) _NOEXCEPT : __i_(__x) {}
95 
96   template <class _Up>
97   friend class __wrap_iter;
98   template <class _CharT, class _Traits, class _Alloc>
99   friend class basic_string;
100   template <class _Tp, class _Alloc>
101   friend class _LIBCPP_TEMPLATE_VIS vector;
102   template <class _Tp, size_t>
103   friend class _LIBCPP_TEMPLATE_VIS span;
104 };
105 
106 template <class _Iter1>
107 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
108 operator==(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT {
109   return __x.base() == __y.base();
110 }
111 
112 template <class _Iter1, class _Iter2>
113 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
114 operator==(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
115   return __x.base() == __y.base();
116 }
117 
118 template <class _Iter1>
119 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool
120 operator<(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT {
121   return __x.base() < __y.base();
122 }
123 
124 template <class _Iter1, class _Iter2>
125 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool
126 operator<(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
127   return __x.base() < __y.base();
128 }
129 
130 template <class _Iter1>
131 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
132 operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT {
133   return !(__x == __y);
134 }
135 
136 template <class _Iter1, class _Iter2>
137 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
138 operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
139   return !(__x == __y);
140 }
141 
142 template <class _Iter1>
143 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
144 operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT {
145   return __y < __x;
146 }
147 
148 template <class _Iter1, class _Iter2>
149 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
150 operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
151   return __y < __x;
152 }
153 
154 template <class _Iter1>
155 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
156 operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT {
157   return !(__x < __y);
158 }
159 
160 template <class _Iter1, class _Iter2>
161 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
162 operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
163   return !(__x < __y);
164 }
165 
166 template <class _Iter1>
167 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
168 operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT {
169   return !(__y < __x);
170 }
171 
172 template <class _Iter1, class _Iter2>
173 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool
174 operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT {
175   return !(__y < __x);
176 }
177 
178 template <class _Iter1, class _Iter2>
179 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
180 #ifndef _LIBCPP_CXX03_LANG
181     auto
182     operator-(const __wrap_iter<_Iter1>& __x,
183               const __wrap_iter<_Iter2>& __y) _NOEXCEPT->decltype(__x.base() - __y.base())
184 #else
185     typename __wrap_iter<_Iter1>::difference_type
186     operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
187 #endif // C++03
188 {
189   return __x.base() - __y.base();
190 }
191 
192 template <class _Iter1>
193 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 __wrap_iter<_Iter1>
194 operator+(typename __wrap_iter<_Iter1>::difference_type __n, __wrap_iter<_Iter1> __x) _NOEXCEPT {
195   __x += __n;
196   return __x;
197 }
198 
199 #if _LIBCPP_STD_VER <= 17
200 template <class _It>
201 struct __libcpp_is_contiguous_iterator<__wrap_iter<_It> > : true_type {};
202 #endif
203 
204 template <class _It>
205 struct _LIBCPP_TEMPLATE_VIS pointer_traits<__wrap_iter<_It> > {
206   typedef __wrap_iter<_It> pointer;
207   typedef typename pointer_traits<_It>::element_type element_type;
208   typedef typename pointer_traits<_It>::difference_type difference_type;
209 
210   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR static element_type* to_address(pointer __w) _NOEXCEPT {
211     return std::__to_address(__w.base());
212   }
213 };
214 
215 _LIBCPP_END_NAMESPACE_STD
216 
217 #endif // _LIBCPP___ITERATOR_WRAP_ITER_H
218