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/pointer_traits.h> // __to_address
17 #include <type_traits>
18 
19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
20 #pragma GCC system_header
21 #endif
22 
23 _LIBCPP_BEGIN_NAMESPACE_STD
24 
25 template <class _Iter>
26 class __wrap_iter
27 {
28 public:
29     typedef _Iter                                                      iterator_type;
30     typedef typename iterator_traits<iterator_type>::value_type        value_type;
31     typedef typename iterator_traits<iterator_type>::difference_type   difference_type;
32     typedef typename iterator_traits<iterator_type>::pointer           pointer;
33     typedef typename iterator_traits<iterator_type>::reference         reference;
34     typedef typename iterator_traits<iterator_type>::iterator_category iterator_category;
35 #if _LIBCPP_STD_VER > 17
36     typedef contiguous_iterator_tag                                    iterator_concept;
37 #endif
38 
39 private:
40     iterator_type __i;
41 public:
42     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter() _NOEXCEPT
43 #if _LIBCPP_STD_VER > 11
44                 : __i{}
45 #endif
46     {
47 #if _LIBCPP_DEBUG_LEVEL == 2
48         __get_db()->__insert_i(this);
49 #endif
50     }
51     template <class _Up> _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
52         __wrap_iter(const __wrap_iter<_Up>& __u,
53             typename enable_if<is_convertible<_Up, iterator_type>::value>::type* = nullptr) _NOEXCEPT
54             : __i(__u.base())
55     {
56 #if _LIBCPP_DEBUG_LEVEL == 2
57         __get_db()->__iterator_copy(this, &__u);
58 #endif
59     }
60 #if _LIBCPP_DEBUG_LEVEL == 2
61     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
62     __wrap_iter(const __wrap_iter& __x)
63         : __i(__x.base())
64     {
65         __get_db()->__iterator_copy(this, &__x);
66     }
67     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
68     __wrap_iter& operator=(const __wrap_iter& __x)
69     {
70         if (this != &__x)
71         {
72             __get_db()->__iterator_copy(this, &__x);
73             __i = __x.__i;
74         }
75         return *this;
76     }
77     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
78     ~__wrap_iter()
79     {
80         __get_db()->__erase_i(this);
81     }
82 #endif
83     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG reference operator*() const _NOEXCEPT
84     {
85 #if _LIBCPP_DEBUG_LEVEL == 2
86         _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
87                        "Attempted to dereference a non-dereferenceable iterator");
88 #endif
89         return *__i;
90     }
91     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG pointer  operator->() const _NOEXCEPT
92     {
93 #if _LIBCPP_DEBUG_LEVEL == 2
94         _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
95                        "Attempted to dereference a non-dereferenceable iterator");
96 #endif
97         return _VSTD::__to_address(__i);
98     }
99     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator++() _NOEXCEPT
100     {
101 #if _LIBCPP_DEBUG_LEVEL == 2
102         _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
103                        "Attempted to increment a non-incrementable iterator");
104 #endif
105         ++__i;
106         return *this;
107     }
108     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator++(int) _NOEXCEPT
109         {__wrap_iter __tmp(*this); ++(*this); return __tmp;}
110 
111     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator--() _NOEXCEPT
112     {
113 #if _LIBCPP_DEBUG_LEVEL == 2
114         _LIBCPP_ASSERT(__get_const_db()->__decrementable(this),
115                        "Attempted to decrement a non-decrementable iterator");
116 #endif
117         --__i;
118         return *this;
119     }
120     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator--(int) _NOEXCEPT
121         {__wrap_iter __tmp(*this); --(*this); return __tmp;}
122     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator+ (difference_type __n) const _NOEXCEPT
123         {__wrap_iter __w(*this); __w += __n; return __w;}
124     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator+=(difference_type __n) _NOEXCEPT
125     {
126 #if _LIBCPP_DEBUG_LEVEL == 2
127         _LIBCPP_ASSERT(__get_const_db()->__addable(this, __n),
128                    "Attempted to add/subtract an iterator outside its valid range");
129 #endif
130         __i += __n;
131         return *this;
132     }
133     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator- (difference_type __n) const _NOEXCEPT
134         {return *this + (-__n);}
135     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator-=(difference_type __n) _NOEXCEPT
136         {*this += -__n; return *this;}
137     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG reference    operator[](difference_type __n) const _NOEXCEPT
138     {
139 #if _LIBCPP_DEBUG_LEVEL == 2
140         _LIBCPP_ASSERT(__get_const_db()->__subscriptable(this, __n),
141                    "Attempted to subscript an iterator outside its valid range");
142 #endif
143         return __i[__n];
144     }
145 
146     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG iterator_type base() const _NOEXCEPT {return __i;}
147 
148 private:
149 #if _LIBCPP_DEBUG_LEVEL == 2
150     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter(const void* __p, iterator_type __x) : __i(__x)
151     {
152         __get_db()->__insert_ic(this, __p);
153     }
154 #else
155     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter(iterator_type __x) _NOEXCEPT : __i(__x) {}
156 #endif
157 
158     template <class _Up> friend class __wrap_iter;
159     template <class _CharT, class _Traits, class _Alloc> friend class basic_string;
160     template <class _Tp, class _Alloc> friend class _LIBCPP_TEMPLATE_VIS vector;
161     template <class _Tp, size_t> friend class _LIBCPP_TEMPLATE_VIS span;
162 };
163 
164 template <class _Iter1>
165 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
166 bool operator==(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
167 {
168     return __x.base() == __y.base();
169 }
170 
171 template <class _Iter1, class _Iter2>
172 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
173 bool operator==(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
174 {
175     return __x.base() == __y.base();
176 }
177 
178 template <class _Iter1>
179 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
180 bool operator<(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
181 {
182 #if _LIBCPP_DEBUG_LEVEL == 2
183     _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
184                    "Attempted to compare incomparable iterators");
185 #endif
186     return __x.base() < __y.base();
187 }
188 
189 template <class _Iter1, class _Iter2>
190 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
191 bool operator<(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
192 {
193 #if _LIBCPP_DEBUG_LEVEL == 2
194     _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
195                    "Attempted to compare incomparable iterators");
196 #endif
197     return __x.base() < __y.base();
198 }
199 
200 template <class _Iter1>
201 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
202 bool operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
203 {
204     return !(__x == __y);
205 }
206 
207 template <class _Iter1, class _Iter2>
208 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
209 bool operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
210 {
211     return !(__x == __y);
212 }
213 
214 template <class _Iter1>
215 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
216 bool operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
217 {
218     return __y < __x;
219 }
220 
221 template <class _Iter1, class _Iter2>
222 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
223 bool operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
224 {
225     return __y < __x;
226 }
227 
228 template <class _Iter1>
229 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
230 bool operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
231 {
232     return !(__x < __y);
233 }
234 
235 template <class _Iter1, class _Iter2>
236 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
237 bool operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
238 {
239     return !(__x < __y);
240 }
241 
242 template <class _Iter1>
243 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
244 bool operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
245 {
246     return !(__y < __x);
247 }
248 
249 template <class _Iter1, class _Iter2>
250 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
251 bool operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
252 {
253     return !(__y < __x);
254 }
255 
256 template <class _Iter1, class _Iter2>
257 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
258 #ifndef _LIBCPP_CXX03_LANG
259 auto operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
260     -> decltype(__x.base() - __y.base())
261 #else
262 typename __wrap_iter<_Iter1>::difference_type
263 operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
264 #endif // C++03
265 {
266 #if _LIBCPP_DEBUG_LEVEL == 2
267     _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
268                    "Attempted to subtract incompatible iterators");
269 #endif
270     return __x.base() - __y.base();
271 }
272 
273 template <class _Iter1>
274 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
275 __wrap_iter<_Iter1> operator+(typename __wrap_iter<_Iter1>::difference_type __n, __wrap_iter<_Iter1> __x) _NOEXCEPT
276 {
277     __x += __n;
278     return __x;
279 }
280 
281 #if _LIBCPP_STD_VER <= 17
282 template <class _It>
283 struct __is_cpp17_contiguous_iterator<__wrap_iter<_It> > : true_type {};
284 #endif
285 
286 template <class _Iter>
287 _LIBCPP_CONSTEXPR
288 decltype(_VSTD::__to_address(declval<_Iter>()))
289 __to_address(__wrap_iter<_Iter> __w) _NOEXCEPT {
290     return _VSTD::__to_address(__w.base());
291 }
292 
293 _LIBCPP_END_NAMESPACE_STD
294 
295 #endif // _LIBCPP___ITERATOR_WRAP_ITER_H
296