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 <__debug>
15 #include <__iterator/iterator_traits.h>
16 #include <__memory/addressof.h>
17 #include <__memory/pointer_traits.h>
18 #include <type_traits>
19 
20 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
21 #  pragma GCC system_header
22 #endif
23 
24 _LIBCPP_BEGIN_NAMESPACE_STD
25 
26 template <class _Iter>
27 class __wrap_iter
28 {
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 > 17
37     typedef contiguous_iterator_tag                                    iterator_concept;
38 #endif
39 
40 private:
41     iterator_type __i;
42 public:
43     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter() _NOEXCEPT
44                 : __i()
45     {
46         _VSTD::__debug_db_insert_i(this);
47     }
48     template <class _Up> _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
49         __wrap_iter(const __wrap_iter<_Up>& __u,
50             typename enable_if<is_convertible<_Up, iterator_type>::value>::type* = nullptr) _NOEXCEPT
51             : __i(__u.base())
52     {
53 #if _LIBCPP_DEBUG_LEVEL == 2
54       if (!__libcpp_is_constant_evaluated())
55         __get_db()->__iterator_copy(this, _VSTD::addressof(__u));
56 #endif
57     }
58 #if _LIBCPP_DEBUG_LEVEL == 2
59     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
60     __wrap_iter(const __wrap_iter& __x)
61         : __i(__x.base())
62     {
63       if (!__libcpp_is_constant_evaluated())
64         __get_db()->__iterator_copy(this, _VSTD::addressof(__x));
65     }
66     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
67     __wrap_iter& operator=(const __wrap_iter& __x)
68     {
69         if (this != _VSTD::addressof(__x))
70         {
71             if (!__libcpp_is_constant_evaluated())
72                 __get_db()->__iterator_copy(this, _VSTD::addressof(__x));
73             __i = __x.__i;
74         }
75         return *this;
76     }
77     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
78     ~__wrap_iter()
79     {
80       if (!__libcpp_is_constant_evaluated())
81         __get_db()->__erase_i(this);
82     }
83 #endif
84     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 reference operator*() const _NOEXCEPT
85     {
86         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
87                              "Attempted to dereference a non-dereferenceable iterator");
88         return *__i;
89     }
90     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 pointer operator->() const _NOEXCEPT
91     {
92         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
93                              "Attempted to dereference a non-dereferenceable iterator");
94         return _VSTD::__to_address(__i);
95     }
96     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter& operator++() _NOEXCEPT
97     {
98         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
99                              "Attempted to increment a non-incrementable iterator");
100         ++__i;
101         return *this;
102     }
103     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter  operator++(int) _NOEXCEPT
104         {__wrap_iter __tmp(*this); ++(*this); return __tmp;}
105 
106     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter& operator--() _NOEXCEPT
107     {
108         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__decrementable(this),
109                              "Attempted to decrement a non-decrementable iterator");
110         --__i;
111         return *this;
112     }
113     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter  operator--(int) _NOEXCEPT
114         {__wrap_iter __tmp(*this); --(*this); return __tmp;}
115     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter  operator+ (difference_type __n) const _NOEXCEPT
116         {__wrap_iter __w(*this); __w += __n; return __w;}
117     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter& operator+=(difference_type __n) _NOEXCEPT
118     {
119         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__addable(this, __n),
120                              "Attempted to add/subtract an iterator outside its valid range");
121         __i += __n;
122         return *this;
123     }
124     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter  operator- (difference_type __n) const _NOEXCEPT
125         {return *this + (-__n);}
126     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter& operator-=(difference_type __n) _NOEXCEPT
127         {*this += -__n; return *this;}
128     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 reference    operator[](difference_type __n) const _NOEXCEPT
129     {
130         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__subscriptable(this, __n),
131                              "Attempted to subscript an iterator outside its valid range");
132         return __i[__n];
133     }
134 
135     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 iterator_type base() const _NOEXCEPT {return __i;}
136 
137 private:
138 #if _LIBCPP_DEBUG_LEVEL == 2
139     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
140     explicit __wrap_iter(const void* __p, iterator_type __x) : __i(__x)
141     {
142       if (!__libcpp_is_constant_evaluated())
143         __get_db()->__insert_ic(this, __p);
144     }
145 #else
146     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
147     explicit __wrap_iter(iterator_type __x) _NOEXCEPT : __i(__x) {}
148 #endif
149 
150     template <class _Up> friend class __wrap_iter;
151     template <class _CharT, class _Traits, class _Alloc> friend class basic_string;
152     template <class _Tp, class _Alloc> friend class _LIBCPP_TEMPLATE_VIS vector;
153     template <class _Tp, size_t> friend class _LIBCPP_TEMPLATE_VIS span;
154 };
155 
156 template <class _Iter1>
157 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
158 bool operator==(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
159 {
160     return __x.base() == __y.base();
161 }
162 
163 template <class _Iter1, class _Iter2>
164 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
165 bool operator==(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
166 {
167     return __x.base() == __y.base();
168 }
169 
170 template <class _Iter1>
171 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
172 bool operator<(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
173 {
174     _LIBCPP_DEBUG_ASSERT(__get_const_db()->__less_than_comparable(_VSTD::addressof(__x), _VSTD::addressof(__y)),
175                          "Attempted to compare incomparable iterators");
176     return __x.base() < __y.base();
177 }
178 
179 template <class _Iter1, class _Iter2>
180 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
181 bool operator<(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
182 {
183     _LIBCPP_DEBUG_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
184                          "Attempted to compare incomparable iterators");
185     return __x.base() < __y.base();
186 }
187 
188 template <class _Iter1>
189 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
190 bool operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
191 {
192     return !(__x == __y);
193 }
194 
195 template <class _Iter1, class _Iter2>
196 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
197 bool operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
198 {
199     return !(__x == __y);
200 }
201 
202 template <class _Iter1>
203 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
204 bool operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
205 {
206     return __y < __x;
207 }
208 
209 template <class _Iter1, class _Iter2>
210 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
211 bool operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
212 {
213     return __y < __x;
214 }
215 
216 template <class _Iter1>
217 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
218 bool operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
219 {
220     return !(__x < __y);
221 }
222 
223 template <class _Iter1, class _Iter2>
224 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
225 bool operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
226 {
227     return !(__x < __y);
228 }
229 
230 template <class _Iter1>
231 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
232 bool operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
233 {
234     return !(__y < __x);
235 }
236 
237 template <class _Iter1, class _Iter2>
238 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
239 bool operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
240 {
241     return !(__y < __x);
242 }
243 
244 template <class _Iter1, class _Iter2>
245 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
246 #ifndef _LIBCPP_CXX03_LANG
247 auto operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
248     -> decltype(__x.base() - __y.base())
249 #else
250 typename __wrap_iter<_Iter1>::difference_type
251 operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
252 #endif // C++03
253 {
254     _LIBCPP_DEBUG_ASSERT(__get_const_db()->__less_than_comparable(_VSTD::addressof(__x), _VSTD::addressof(__y)),
255                          "Attempted to subtract incompatible iterators");
256     return __x.base() - __y.base();
257 }
258 
259 template <class _Iter1>
260 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
261 __wrap_iter<_Iter1> operator+(typename __wrap_iter<_Iter1>::difference_type __n, __wrap_iter<_Iter1> __x) _NOEXCEPT
262 {
263     __x += __n;
264     return __x;
265 }
266 
267 #if _LIBCPP_STD_VER <= 17
268 template <class _It>
269 struct __is_cpp17_contiguous_iterator<__wrap_iter<_It> > : true_type {};
270 #endif
271 
272 template <class _It>
273 struct _LIBCPP_TEMPLATE_VIS pointer_traits<__wrap_iter<_It> >
274 {
275     typedef __wrap_iter<_It> pointer;
276     typedef typename pointer_traits<_It>::element_type element_type;
277     typedef typename pointer_traits<_It>::difference_type difference_type;
278 
279     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
280     static element_type *to_address(pointer __w) _NOEXCEPT {
281         return _VSTD::__to_address(__w.base());
282     }
283 };
284 
285 _LIBCPP_END_NAMESPACE_STD
286 
287 #endif // _LIBCPP___ITERATOR_WRAP_ITER_H
288