libstdc++
enable_special_members.h
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1 // <bits/enable_special_members.h> -*- C++ -*-
2 
3 // Copyright (C) 2013-2022 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/enable_special_members.h
26  * This is an internal header file, included by other library headers.
27  * Do not attempt to use it directly.
28  */
29 
30 #ifndef _ENABLE_SPECIAL_MEMBERS_H
31 #define _ENABLE_SPECIAL_MEMBERS_H 1
32 
33 #pragma GCC system_header
34 
35 #include <bits/c++config.h>
36 
37 namespace std _GLIBCXX_VISIBILITY(default)
38 {
39 _GLIBCXX_BEGIN_NAMESPACE_VERSION
40 /// @cond undocumented
41 
42  struct _Enable_default_constructor_tag
43  {
44  explicit constexpr _Enable_default_constructor_tag() = default;
45  };
46 
47 /**
48  * @brief A mixin helper to conditionally enable or disable the default
49  * constructor.
50  * @sa _Enable_special_members
51  */
52 template<bool _Switch, typename _Tag = void>
53  struct _Enable_default_constructor
54  {
55  constexpr _Enable_default_constructor() noexcept = default;
56  constexpr _Enable_default_constructor(_Enable_default_constructor const&)
57  noexcept = default;
58  constexpr _Enable_default_constructor(_Enable_default_constructor&&)
59  noexcept = default;
60  _Enable_default_constructor&
61  operator=(_Enable_default_constructor const&) noexcept = default;
62  _Enable_default_constructor&
63  operator=(_Enable_default_constructor&&) noexcept = default;
64 
65  // Can be used in other ctors.
66  constexpr explicit
67  _Enable_default_constructor(_Enable_default_constructor_tag) { }
68  };
69 
70 
71 /**
72  * @brief A mixin helper to conditionally enable or disable the default
73  * destructor.
74  * @sa _Enable_special_members
75  */
76 template<bool _Switch, typename _Tag = void>
77  struct _Enable_destructor { };
78 
79 /**
80  * @brief A mixin helper to conditionally enable or disable the copy/move
81  * special members.
82  * @sa _Enable_special_members
83  */
84 template<bool _Copy, bool _CopyAssignment,
85  bool _Move, bool _MoveAssignment,
86  typename _Tag = void>
87  struct _Enable_copy_move { };
88 
89 /**
90  * @brief A mixin helper to conditionally enable or disable the special
91  * members.
92  *
93  * The @c _Tag type parameter is to make mixin bases unique and thus avoid
94  * ambiguities.
95  */
96 template<bool _Default, bool _Destructor,
97  bool _Copy, bool _CopyAssignment,
98  bool _Move, bool _MoveAssignment,
99  typename _Tag = void>
100  struct _Enable_special_members
101  : private _Enable_default_constructor<_Default, _Tag>,
102  private _Enable_destructor<_Destructor, _Tag>,
103  private _Enable_copy_move<_Copy, _CopyAssignment,
104  _Move, _MoveAssignment,
105  _Tag>
106  { };
107 
108 // Boilerplate follows.
109 
110 template<typename _Tag>
111  struct _Enable_default_constructor<false, _Tag>
112  {
113  constexpr _Enable_default_constructor() noexcept = delete;
114  constexpr _Enable_default_constructor(_Enable_default_constructor const&)
115  noexcept = default;
116  constexpr _Enable_default_constructor(_Enable_default_constructor&&)
117  noexcept = default;
118  _Enable_default_constructor&
119  operator=(_Enable_default_constructor const&) noexcept = default;
120  _Enable_default_constructor&
121  operator=(_Enable_default_constructor&&) noexcept = default;
122 
123  // Can be used in other ctors.
124  constexpr explicit
125  _Enable_default_constructor(_Enable_default_constructor_tag) { }
126  };
127 
128 template<typename _Tag>
129  struct _Enable_destructor<false, _Tag>
130  { ~_Enable_destructor() noexcept = delete; };
131 
132 template<typename _Tag>
133  struct _Enable_copy_move<false, true, true, true, _Tag>
134  {
135  constexpr _Enable_copy_move() noexcept = default;
136  constexpr _Enable_copy_move(_Enable_copy_move const&) noexcept = delete;
137  constexpr _Enable_copy_move(_Enable_copy_move&&) noexcept = default;
138  _Enable_copy_move&
139  operator=(_Enable_copy_move const&) noexcept = default;
140  _Enable_copy_move&
141  operator=(_Enable_copy_move&&) noexcept = default;
142  };
143 
144 template<typename _Tag>
145  struct _Enable_copy_move<true, false, true, true, _Tag>
146  {
147  constexpr _Enable_copy_move() noexcept = default;
148  constexpr _Enable_copy_move(_Enable_copy_move const&) noexcept = default;
149  constexpr _Enable_copy_move(_Enable_copy_move&&) noexcept = default;
150  _Enable_copy_move&
151  operator=(_Enable_copy_move const&) noexcept = delete;
152  _Enable_copy_move&
153  operator=(_Enable_copy_move&&) noexcept = default;
154  };
155 
156 template<typename _Tag>
157  struct _Enable_copy_move<false, false, true, true, _Tag>
158  {
159  constexpr _Enable_copy_move() noexcept = default;
160  constexpr _Enable_copy_move(_Enable_copy_move const&) noexcept = delete;
161  constexpr _Enable_copy_move(_Enable_copy_move&&) noexcept = default;
162  _Enable_copy_move&
163  operator=(_Enable_copy_move const&) noexcept = delete;
164  _Enable_copy_move&
165  operator=(_Enable_copy_move&&) noexcept = default;
166  };
167 
168 template<typename _Tag>
169  struct _Enable_copy_move<true, true, false, true, _Tag>
170  {
171  constexpr _Enable_copy_move() noexcept = default;
172  constexpr _Enable_copy_move(_Enable_copy_move const&) noexcept = default;
173  constexpr _Enable_copy_move(_Enable_copy_move&&) noexcept = delete;
174  _Enable_copy_move&
175  operator=(_Enable_copy_move const&) noexcept = default;
176  _Enable_copy_move&
177  operator=(_Enable_copy_move&&) noexcept = default;
178  };
179 
180 template<typename _Tag>
181  struct _Enable_copy_move<false, true, false, true, _Tag>
182  {
183  constexpr _Enable_copy_move() noexcept = default;
184  constexpr _Enable_copy_move(_Enable_copy_move const&) noexcept = delete;
185  constexpr _Enable_copy_move(_Enable_copy_move&&) noexcept = delete;
186  _Enable_copy_move&
187  operator=(_Enable_copy_move const&) noexcept = default;
188  _Enable_copy_move&
189  operator=(_Enable_copy_move&&) noexcept = default;
190  };
191 
192 template<typename _Tag>
193  struct _Enable_copy_move<true, false, false, true, _Tag>
194  {
195  constexpr _Enable_copy_move() noexcept = default;
196  constexpr _Enable_copy_move(_Enable_copy_move const&) noexcept = default;
197  constexpr _Enable_copy_move(_Enable_copy_move&&) noexcept = delete;
198  _Enable_copy_move&
199  operator=(_Enable_copy_move const&) noexcept = delete;
200  _Enable_copy_move&
201  operator=(_Enable_copy_move&&) noexcept = default;
202  };
203 
204 template<typename _Tag>
205  struct _Enable_copy_move<false, false, false, true, _Tag>
206  {
207  constexpr _Enable_copy_move() noexcept = default;
208  constexpr _Enable_copy_move(_Enable_copy_move const&) noexcept = delete;
209  constexpr _Enable_copy_move(_Enable_copy_move&&) noexcept = delete;
210  _Enable_copy_move&
211  operator=(_Enable_copy_move const&) noexcept = delete;
212  _Enable_copy_move&
213  operator=(_Enable_copy_move&&) noexcept = default;
214  };
215 
216 template<typename _Tag>
217  struct _Enable_copy_move<true, true, true, false, _Tag>
218  {
219  constexpr _Enable_copy_move() noexcept = default;
220  constexpr _Enable_copy_move(_Enable_copy_move const&) noexcept = default;
221  constexpr _Enable_copy_move(_Enable_copy_move&&) noexcept = default;
222  _Enable_copy_move&
223  operator=(_Enable_copy_move const&) noexcept = default;
224  _Enable_copy_move&
225  operator=(_Enable_copy_move&&) noexcept = delete;
226  };
227 
228 template<typename _Tag>
229  struct _Enable_copy_move<false, true, true, false, _Tag>
230  {
231  constexpr _Enable_copy_move() noexcept = default;
232  constexpr _Enable_copy_move(_Enable_copy_move const&) noexcept = delete;
233  constexpr _Enable_copy_move(_Enable_copy_move&&) noexcept = default;
234  _Enable_copy_move&
235  operator=(_Enable_copy_move const&) noexcept = default;
236  _Enable_copy_move&
237  operator=(_Enable_copy_move&&) noexcept = delete;
238  };
239 
240 template<typename _Tag>
241  struct _Enable_copy_move<true, false, true, false, _Tag>
242  {
243  constexpr _Enable_copy_move() noexcept = default;
244  constexpr _Enable_copy_move(_Enable_copy_move const&) noexcept = default;
245  constexpr _Enable_copy_move(_Enable_copy_move&&) noexcept = default;
246  _Enable_copy_move&
247  operator=(_Enable_copy_move const&) noexcept = delete;
248  _Enable_copy_move&
249  operator=(_Enable_copy_move&&) noexcept = delete;
250  };
251 
252 template<typename _Tag>
253  struct _Enable_copy_move<false, false, true, false, _Tag>
254  {
255  constexpr _Enable_copy_move() noexcept = default;
256  constexpr _Enable_copy_move(_Enable_copy_move const&) noexcept = delete;
257  constexpr _Enable_copy_move(_Enable_copy_move&&) noexcept = default;
258  _Enable_copy_move&
259  operator=(_Enable_copy_move const&) noexcept = delete;
260  _Enable_copy_move&
261  operator=(_Enable_copy_move&&) noexcept = delete;
262  };
263 
264 template<typename _Tag>
265  struct _Enable_copy_move<true, true, false, false, _Tag>
266  {
267  constexpr _Enable_copy_move() noexcept = default;
268  constexpr _Enable_copy_move(_Enable_copy_move const&) noexcept = default;
269  constexpr _Enable_copy_move(_Enable_copy_move&&) noexcept = delete;
270  _Enable_copy_move&
271  operator=(_Enable_copy_move const&) noexcept = default;
272  _Enable_copy_move&
273  operator=(_Enable_copy_move&&) noexcept = delete;
274  };
275 
276 template<typename _Tag>
277  struct _Enable_copy_move<false, true, false, false, _Tag>
278  {
279  constexpr _Enable_copy_move() noexcept = default;
280  constexpr _Enable_copy_move(_Enable_copy_move const&) noexcept = delete;
281  constexpr _Enable_copy_move(_Enable_copy_move&&) noexcept = delete;
282  _Enable_copy_move&
283  operator=(_Enable_copy_move const&) noexcept = default;
284  _Enable_copy_move&
285  operator=(_Enable_copy_move&&) noexcept = delete;
286  };
287 
288 template<typename _Tag>
289  struct _Enable_copy_move<true, false, false, false, _Tag>
290  {
291  constexpr _Enable_copy_move() noexcept = default;
292  constexpr _Enable_copy_move(_Enable_copy_move const&) noexcept = default;
293  constexpr _Enable_copy_move(_Enable_copy_move&&) noexcept = delete;
294  _Enable_copy_move&
295  operator=(_Enable_copy_move const&) noexcept = delete;
296  _Enable_copy_move&
297  operator=(_Enable_copy_move&&) noexcept = delete;
298  };
299 
300 template<typename _Tag>
301  struct _Enable_copy_move<false, false, false, false, _Tag>
302  {
303  constexpr _Enable_copy_move() noexcept = default;
304  constexpr _Enable_copy_move(_Enable_copy_move const&) noexcept = delete;
305  constexpr _Enable_copy_move(_Enable_copy_move&&) noexcept = delete;
306  _Enable_copy_move&
307  operator=(_Enable_copy_move const&) noexcept = delete;
308  _Enable_copy_move&
309  operator=(_Enable_copy_move&&) noexcept = delete;
310  };
311 
312 /// @endcond
313 _GLIBCXX_END_NAMESPACE_VERSION
314 } // namespace std
315 
316 #endif // _ENABLE_SPECIAL_MEMBERS_H
std
ISO C++ entities toplevel namespace is std.