range_access.h revision 1.8 
1// <range_access.h> -*- C++ -*-
2
3// Copyright (C) 2010-2019 Free Software Foundation, Inc.
4//
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)
9// any later version.
10
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.
15
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.
19
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/>.
24
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}
28 */
29
30#ifndef _GLIBCXX_RANGE_ACCESS_H
31#define _GLIBCXX_RANGE_ACCESS_H 1
32
33#pragma GCC system_header
34
35#if __cplusplus >= 201103L
36#include <initializer_list>
37namespace std _GLIBCXX_VISIBILITY(default)
38{
39_GLIBCXX_BEGIN_NAMESPACE_VERSION
40
41  /**
42   *  @brief  Return an iterator pointing to the first element of
43   *          the container.
44   *  @param  __cont  Container.
45   */
46  template<typename _Container>
47    inline _GLIBCXX17_CONSTEXPR auto
48    begin(_Container& __cont) -> decltype(__cont.begin())
49    { return __cont.begin(); }
50
51  /**
52   *  @brief  Return an iterator pointing to the first element of
53   *          the const container.
54   *  @param  __cont  Container.
55   */
56  template<typename _Container>
57    inline _GLIBCXX17_CONSTEXPR auto
58    begin(const _Container& __cont) -> decltype(__cont.begin())
59    { return __cont.begin(); }
60
61  /**
62   *  @brief  Return an iterator pointing to one past the last element of
63   *          the container.
64   *  @param  __cont  Container.
65   */
66  template<typename _Container>
67    inline _GLIBCXX17_CONSTEXPR auto
68    end(_Container& __cont) -> decltype(__cont.end())
69    { return __cont.end(); }
70
71  /**
72   *  @brief  Return an iterator pointing to one past the last element of
73   *          the const container.
74   *  @param  __cont  Container.
75   */
76  template<typename _Container>
77    inline _GLIBCXX17_CONSTEXPR auto
78    end(const _Container& __cont) -> decltype(__cont.end())
79    { return __cont.end(); }
80
81  /**
82   *  @brief  Return an iterator pointing to the first element of the array.
83   *  @param  __arr  Array.
84   */
85  template<typename _Tp, size_t _Nm>
86    inline _GLIBCXX14_CONSTEXPR _Tp*
87    begin(_Tp (&__arr)[_Nm])
88    { return __arr; }
89
90  /**
91   *  @brief  Return an iterator pointing to one past the last element
92   *          of the array.
93   *  @param  __arr  Array.
94   */
95  template<typename _Tp, size_t _Nm>
96    inline _GLIBCXX14_CONSTEXPR _Tp*
97    end(_Tp (&__arr)[_Nm])
98    { return __arr + _Nm; }
99
100#if __cplusplus >= 201402L
101
102  template<typename _Tp> class valarray;
103  // These overloads must be declared for cbegin and cend to use them.
104  template<typename _Tp> _Tp* begin(valarray<_Tp>&);
105  template<typename _Tp> const _Tp* begin(const valarray<_Tp>&);
106  template<typename _Tp> _Tp* end(valarray<_Tp>&);
107  template<typename _Tp> const _Tp* end(const valarray<_Tp>&);
108
109  /**
110   *  @brief  Return an iterator pointing to the first element of
111   *          the const container.
112   *  @param  __cont  Container.
113   */
114  template<typename _Container>
115    inline constexpr auto
116    cbegin(const _Container& __cont) noexcept(noexcept(std::begin(__cont)))
117      -> decltype(std::begin(__cont))
118    { return std::begin(__cont); }
119
120  /**
121   *  @brief  Return an iterator pointing to one past the last element of
122   *          the const container.
123   *  @param  __cont  Container.
124   */
125  template<typename _Container>
126    inline constexpr auto
127    cend(const _Container& __cont) noexcept(noexcept(std::end(__cont)))
128      -> decltype(std::end(__cont))
129    { return std::end(__cont); }
130
131  /**
132   *  @brief  Return a reverse iterator pointing to the last element of
133   *          the container.
134   *  @param  __cont  Container.
135   */
136  template<typename _Container>
137    inline _GLIBCXX17_CONSTEXPR auto
138    rbegin(_Container& __cont) -> decltype(__cont.rbegin())
139    { return __cont.rbegin(); }
140
141  /**
142   *  @brief  Return a reverse iterator pointing to the last element of
143   *          the const container.
144   *  @param  __cont  Container.
145   */
146  template<typename _Container>
147    inline _GLIBCXX17_CONSTEXPR auto
148    rbegin(const _Container& __cont) -> decltype(__cont.rbegin())
149    { return __cont.rbegin(); }
150
151  /**
152   *  @brief  Return a reverse iterator pointing one past the first element of
153   *          the container.
154   *  @param  __cont  Container.
155   */
156  template<typename _Container>
157    inline _GLIBCXX17_CONSTEXPR auto
158    rend(_Container& __cont) -> decltype(__cont.rend())
159    { return __cont.rend(); }
160
161  /**
162   *  @brief  Return a reverse iterator pointing one past the first element of
163   *          the const container.
164   *  @param  __cont  Container.
165   */
166  template<typename _Container>
167    inline _GLIBCXX17_CONSTEXPR auto
168    rend(const _Container& __cont) -> decltype(__cont.rend())
169    { return __cont.rend(); }
170
171  /**
172   *  @brief  Return a reverse iterator pointing to the last element of
173   *          the array.
174   *  @param  __arr  Array.
175   */
176  template<typename _Tp, size_t _Nm>
177    inline _GLIBCXX17_CONSTEXPR reverse_iterator<_Tp*>
178    rbegin(_Tp (&__arr)[_Nm])
179    { return reverse_iterator<_Tp*>(__arr + _Nm); }
180
181  /**
182   *  @brief  Return a reverse iterator pointing one past the first element of
183   *          the array.
184   *  @param  __arr  Array.
185   */
186  template<typename _Tp, size_t _Nm>
187    inline _GLIBCXX17_CONSTEXPR reverse_iterator<_Tp*>
188    rend(_Tp (&__arr)[_Nm])
189    { return reverse_iterator<_Tp*>(__arr); }
190
191  /**
192   *  @brief  Return a reverse iterator pointing to the last element of
193   *          the initializer_list.
194   *  @param  __il  initializer_list.
195   */
196  template<typename _Tp>
197    inline _GLIBCXX17_CONSTEXPR reverse_iterator<const _Tp*>
198    rbegin(initializer_list<_Tp> __il)
199    { return reverse_iterator<const _Tp*>(__il.end()); }
200
201  /**
202   *  @brief  Return a reverse iterator pointing one past the first element of
203   *          the initializer_list.
204   *  @param  __il  initializer_list.
205   */
206  template<typename _Tp>
207    inline _GLIBCXX17_CONSTEXPR reverse_iterator<const _Tp*>
208    rend(initializer_list<_Tp> __il)
209    { return reverse_iterator<const _Tp*>(__il.begin()); }
210
211  /**
212   *  @brief  Return a reverse iterator pointing to the last element of
213   *          the const container.
214   *  @param  __cont  Container.
215   */
216  template<typename _Container>
217    inline _GLIBCXX17_CONSTEXPR auto
218    crbegin(const _Container& __cont) -> decltype(std::rbegin(__cont))
219    { return std::rbegin(__cont); }
220
221  /**
222   *  @brief  Return a reverse iterator pointing one past the first element of
223   *          the const container.
224   *  @param  __cont  Container.
225   */
226  template<typename _Container>
227    inline _GLIBCXX17_CONSTEXPR auto
228    crend(const _Container& __cont) -> decltype(std::rend(__cont))
229    { return std::rend(__cont); }
230
231#endif // C++14
232
233#if __cplusplus >= 201703L
234#define __cpp_lib_nonmember_container_access 201411
235
236  /**
237   *  @brief  Return the size of a container.
238   *  @param  __cont  Container.
239   */
240  template <typename _Container>
241    constexpr auto
242    size(const _Container& __cont) noexcept(noexcept(__cont.size()))
243    -> decltype(__cont.size())
244    { return __cont.size(); }
245
246  /**
247   *  @brief  Return the size of an array.
248   *  @param  __array  Array.
249   */
250  template <typename _Tp, size_t _Nm>
251    constexpr size_t
252    size(const _Tp (&/*__array*/)[_Nm]) noexcept
253    { return _Nm; }
254
255  /**
256   *  @brief  Return whether a container is empty.
257   *  @param  __cont  Container.
258   */
259  template <typename _Container>
260    [[nodiscard]] constexpr auto
261    empty(const _Container& __cont) noexcept(noexcept(__cont.empty()))
262    -> decltype(__cont.empty())
263    { return __cont.empty(); }
264
265  /**
266   *  @brief  Return whether an array is empty (always false).
267   *  @param  __array  Container.
268   */
269  template <typename _Tp, size_t _Nm>
270    [[nodiscard]] constexpr bool
271    empty(const _Tp (&/*__array*/)[_Nm]) noexcept
272    { return false; }
273
274  /**
275   *  @brief  Return whether an initializer_list is empty.
276   *  @param  __il  Initializer list.
277   */
278  template <typename _Tp>
279    [[nodiscard]] constexpr bool
280    empty(initializer_list<_Tp> __il) noexcept
281    { return __il.size() == 0;}
282
283  /**
284   *  @brief  Return the data pointer of a container.
285   *  @param  __cont  Container.
286   */
287  template <typename _Container>
288    constexpr auto
289    data(_Container& __cont) noexcept(noexcept(__cont.data()))
290    -> decltype(__cont.data())
291    { return __cont.data(); }
292
293  /**
294   *  @brief  Return the data pointer of a const container.
295   *  @param  __cont  Container.
296   */
297  template <typename _Container>
298    constexpr auto
299    data(const _Container& __cont) noexcept(noexcept(__cont.data()))
300    -> decltype(__cont.data())
301    { return __cont.data(); }
302
303  /**
304   *  @brief  Return the data pointer of an array.
305   *  @param  __array  Array.
306   */
307  template <typename _Tp, size_t _Nm>
308    constexpr _Tp*
309    data(_Tp (&__array)[_Nm]) noexcept
310    { return __array; }
311
312  /**
313   *  @brief  Return the data pointer of an initializer list.
314   *  @param  __il  Initializer list.
315   */
316  template <typename _Tp>
317    constexpr const _Tp*
318    data(initializer_list<_Tp> __il) noexcept
319    { return __il.begin(); }
320
321#endif // C++17
322
323_GLIBCXX_END_NAMESPACE_VERSION
324} // namespace
325
326#endif // C++11
327
328#endif // _GLIBCXX_RANGE_ACCESS_H
329