1 // Range access functions for containers -*- C++ -*-
3 // Copyright (C) 2010-2021 Free Software Foundation, Inc.
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
25 /** @file bits/range_access.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{iterator}
30 #ifndef _GLIBCXX_RANGE_ACCESS_H
31 #define _GLIBCXX_RANGE_ACCESS_H 1
33 #pragma GCC system_header
35 #if __cplusplus >= 201103L
36 #include <initializer_list>
37 #include <type_traits> // common_type_t, make_signed_t
39 namespace std
_GLIBCXX_VISIBILITY(default)
41 _GLIBCXX_BEGIN_NAMESPACE_VERSION
44 * @brief Return an iterator pointing to the first element of
46 * @param __cont Container.
48 template<typename _Container
>
49 inline _GLIBCXX17_CONSTEXPR
auto
50 begin(_Container
& __cont
) -> decltype(__cont
.begin())
51 { return __cont
.begin(); }
54 * @brief Return an iterator pointing to the first element of
55 * the const container.
56 * @param __cont Container.
58 template<typename _Container
>
59 inline _GLIBCXX17_CONSTEXPR
auto
60 begin(const _Container
& __cont
) -> decltype(__cont
.begin())
61 { return __cont
.begin(); }
64 * @brief Return an iterator pointing to one past the last element of
66 * @param __cont Container.
68 template<typename _Container
>
69 inline _GLIBCXX17_CONSTEXPR
auto
70 end(_Container
& __cont
) -> decltype(__cont
.end())
71 { return __cont
.end(); }
74 * @brief Return an iterator pointing to one past the last element of
75 * the const container.
76 * @param __cont Container.
78 template<typename _Container
>
79 inline _GLIBCXX17_CONSTEXPR
auto
80 end(const _Container
& __cont
) -> decltype(__cont
.end())
81 { return __cont
.end(); }
84 * @brief Return an iterator pointing to the first element of the array.
87 template<typename _Tp
, size_t _Nm
>
88 inline _GLIBCXX14_CONSTEXPR _Tp
*
89 begin(_Tp (&__arr
)[_Nm
])
93 * @brief Return an iterator pointing to one past the last element
97 template<typename _Tp
, size_t _Nm
>
98 inline _GLIBCXX14_CONSTEXPR _Tp
*
99 end(_Tp (&__arr
)[_Nm
])
100 { return __arr
+ _Nm
; }
102 #if __cplusplus >= 201402L
104 template<typename _Tp
> class valarray
;
105 // These overloads must be declared for cbegin and cend to use them.
106 template<typename _Tp
> _Tp
* begin(valarray
<_Tp
>&);
107 template<typename _Tp
> const _Tp
* begin(const valarray
<_Tp
>&);
108 template<typename _Tp
> _Tp
* end(valarray
<_Tp
>&);
109 template<typename _Tp
> const _Tp
* end(const valarray
<_Tp
>&);
112 * @brief Return an iterator pointing to the first element of
113 * the const container.
114 * @param __cont Container.
116 template<typename _Container
>
117 inline constexpr auto
118 cbegin(const _Container
& __cont
) noexcept(noexcept(std::begin(__cont
)))
119 -> decltype(std::begin(__cont
))
120 { return std::begin(__cont
); }
123 * @brief Return an iterator pointing to one past the last element of
124 * the const container.
125 * @param __cont Container.
127 template<typename _Container
>
128 inline constexpr auto
129 cend(const _Container
& __cont
) noexcept(noexcept(std::end(__cont
)))
130 -> decltype(std::end(__cont
))
131 { return std::end(__cont
); }
134 * @brief Return a reverse iterator pointing to the last element of
136 * @param __cont Container.
138 template<typename _Container
>
139 inline _GLIBCXX17_CONSTEXPR
auto
140 rbegin(_Container
& __cont
) -> decltype(__cont
.rbegin())
141 { return __cont
.rbegin(); }
144 * @brief Return a reverse iterator pointing to the last element of
145 * the const container.
146 * @param __cont Container.
148 template<typename _Container
>
149 inline _GLIBCXX17_CONSTEXPR
auto
150 rbegin(const _Container
& __cont
) -> decltype(__cont
.rbegin())
151 { return __cont
.rbegin(); }
154 * @brief Return a reverse iterator pointing one past the first element of
156 * @param __cont Container.
158 template<typename _Container
>
159 inline _GLIBCXX17_CONSTEXPR
auto
160 rend(_Container
& __cont
) -> decltype(__cont
.rend())
161 { return __cont
.rend(); }
164 * @brief Return a reverse iterator pointing one past the first element of
165 * the const container.
166 * @param __cont Container.
168 template<typename _Container
>
169 inline _GLIBCXX17_CONSTEXPR
auto
170 rend(const _Container
& __cont
) -> decltype(__cont
.rend())
171 { return __cont
.rend(); }
174 * @brief Return a reverse iterator pointing to the last element of
176 * @param __arr Array.
178 template<typename _Tp
, size_t _Nm
>
179 inline _GLIBCXX17_CONSTEXPR reverse_iterator
<_Tp
*>
180 rbegin(_Tp (&__arr
)[_Nm
])
181 { return reverse_iterator
<_Tp
*>(__arr
+ _Nm
); }
184 * @brief Return a reverse iterator pointing one past the first element of
186 * @param __arr Array.
188 template<typename _Tp
, size_t _Nm
>
189 inline _GLIBCXX17_CONSTEXPR reverse_iterator
<_Tp
*>
190 rend(_Tp (&__arr
)[_Nm
])
191 { return reverse_iterator
<_Tp
*>(__arr
); }
194 * @brief Return a reverse iterator pointing to the last element of
195 * the initializer_list.
196 * @param __il initializer_list.
198 template<typename _Tp
>
199 inline _GLIBCXX17_CONSTEXPR reverse_iterator
<const _Tp
*>
200 rbegin(initializer_list
<_Tp
> __il
)
201 { return reverse_iterator
<const _Tp
*>(__il
.end()); }
204 * @brief Return a reverse iterator pointing one past the first element of
205 * the initializer_list.
206 * @param __il initializer_list.
208 template<typename _Tp
>
209 inline _GLIBCXX17_CONSTEXPR reverse_iterator
<const _Tp
*>
210 rend(initializer_list
<_Tp
> __il
)
211 { return reverse_iterator
<const _Tp
*>(__il
.begin()); }
214 * @brief Return a reverse iterator pointing to the last element of
215 * the const container.
216 * @param __cont Container.
218 template<typename _Container
>
219 inline _GLIBCXX17_CONSTEXPR
auto
220 crbegin(const _Container
& __cont
) -> decltype(std::rbegin(__cont
))
221 { return std::rbegin(__cont
); }
224 * @brief Return a reverse iterator pointing one past the first element of
225 * the const container.
226 * @param __cont Container.
228 template<typename _Container
>
229 inline _GLIBCXX17_CONSTEXPR
auto
230 crend(const _Container
& __cont
) -> decltype(std::rend(__cont
))
231 { return std::rend(__cont
); }
235 #if __cplusplus >= 201703L
236 #define __cpp_lib_nonmember_container_access 201411
239 * @brief Return the size of a container.
240 * @param __cont Container.
242 template <typename _Container
>
244 size(const _Container
& __cont
) noexcept(noexcept(__cont
.size()))
245 -> decltype(__cont
.size())
246 { return __cont
.size(); }
249 * @brief Return the size of an array.
251 template <typename _Tp
, size_t _Nm
>
253 size(const _Tp (&)[_Nm
]) noexcept
257 * @brief Return whether a container is empty.
258 * @param __cont Container.
260 template <typename _Container
>
261 [[nodiscard
]] constexpr auto
262 empty(const _Container
& __cont
) noexcept(noexcept(__cont
.empty()))
263 -> decltype(__cont
.empty())
264 { return __cont
.empty(); }
267 * @brief Return whether an array is empty (always false).
269 template <typename _Tp
, size_t _Nm
>
270 [[nodiscard
]] constexpr bool
271 empty(const _Tp (&)[_Nm
]) noexcept
275 * @brief Return whether an initializer_list is empty.
276 * @param __il Initializer list.
278 template <typename _Tp
>
279 [[nodiscard
]] constexpr bool
280 empty(initializer_list
<_Tp
> __il
) noexcept
281 { return __il
.size() == 0;}
284 * @brief Return the data pointer of a container.
285 * @param __cont Container.
287 template <typename _Container
>
289 data(_Container
& __cont
) noexcept(noexcept(__cont
.data()))
290 -> decltype(__cont
.data())
291 { return __cont
.data(); }
294 * @brief Return the data pointer of a const container.
295 * @param __cont Container.
297 template <typename _Container
>
299 data(const _Container
& __cont
) noexcept(noexcept(__cont
.data()))
300 -> decltype(__cont
.data())
301 { return __cont
.data(); }
304 * @brief Return the data pointer of an array.
305 * @param __array Array.
307 template <typename _Tp
, size_t _Nm
>
309 data(_Tp (&__array
)[_Nm
]) noexcept
313 * @brief Return the data pointer of an initializer list.
314 * @param __il Initializer list.
316 template <typename _Tp
>
318 data(initializer_list
<_Tp
> __il
) noexcept
319 { return __il
.begin(); }
321 #if __cplusplus > 201703L
322 #define __cpp_lib_ssize 201902L
323 template<typename _Container
>
325 ssize(const _Container
& __cont
)
326 noexcept(noexcept(__cont
.size()))
327 -> common_type_t
<ptrdiff_t, make_signed_t
<decltype(__cont
.size())>>
329 using type
= make_signed_t
<decltype(__cont
.size())>;
330 return static_cast<common_type_t
<ptrdiff_t, type
>>(__cont
.size());
333 template<typename _Tp
, ptrdiff_t _Num
>
335 ssize(const _Tp (&)[_Num
]) noexcept
340 _GLIBCXX_END_NAMESPACE_VERSION
344 #endif // _GLIBCXX_RANGE_ACCESS_H