1 // <bits/enable_special_members.h> -*- C++ -*-
3 // Copyright (C) 2013-2018 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/enable_special_members.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly.
30 #ifndef _ENABLE_SPECIAL_MEMBERS_H
31 #define _ENABLE_SPECIAL_MEMBERS_H 1
33 #pragma GCC system_header
35 namespace std
_GLIBCXX_VISIBILITY(default)
37 _GLIBCXX_BEGIN_NAMESPACE_VERSION
39 struct _Enable_default_constructor_tag
41 explicit constexpr _Enable_default_constructor_tag() = default;
45 * @brief A mixin helper to conditionally enable or disable the default
47 * @sa _Enable_special_members
49 template<bool _Switch
, typename _Tag
= void>
50 struct _Enable_default_constructor
52 constexpr _Enable_default_constructor() noexcept
= default;
53 constexpr _Enable_default_constructor(_Enable_default_constructor
const&)
55 constexpr _Enable_default_constructor(_Enable_default_constructor
&&)
57 _Enable_default_constructor
&
58 operator=(_Enable_default_constructor
const&) noexcept
= default;
59 _Enable_default_constructor
&
60 operator=(_Enable_default_constructor
&&) noexcept
= default;
62 // Can be used in other ctors.
64 _Enable_default_constructor(_Enable_default_constructor_tag
) { }
69 * @brief A mixin helper to conditionally enable or disable the default
71 * @sa _Enable_special_members
73 template<bool _Switch
, typename _Tag
= void>
74 struct _Enable_destructor
{ };
77 * @brief A mixin helper to conditionally enable or disable the copy/move
79 * @sa _Enable_special_members
81 template<bool _Copy
, bool _CopyAssignment
,
82 bool _Move
, bool _MoveAssignment
,
84 struct _Enable_copy_move
{ };
87 * @brief A mixin helper to conditionally enable or disable the special
90 * The @c _Tag type parameter is to make mixin bases unique and thus avoid
93 template<bool _Default
, bool _Destructor
,
94 bool _Copy
, bool _CopyAssignment
,
95 bool _Move
, bool _MoveAssignment
,
97 struct _Enable_special_members
98 : private _Enable_default_constructor
<_Default
, _Tag
>,
99 private _Enable_destructor
<_Destructor
, _Tag
>,
100 private _Enable_copy_move
<_Copy
, _CopyAssignment
,
101 _Move
, _MoveAssignment
,
105 // Boilerplate follows.
107 template<typename _Tag
>
108 struct _Enable_default_constructor
<false, _Tag
>
110 constexpr _Enable_default_constructor() noexcept
= delete;
111 constexpr _Enable_default_constructor(_Enable_default_constructor
const&)
113 constexpr _Enable_default_constructor(_Enable_default_constructor
&&)
115 _Enable_default_constructor
&
116 operator=(_Enable_default_constructor
const&) noexcept
= default;
117 _Enable_default_constructor
&
118 operator=(_Enable_default_constructor
&&) noexcept
= default;
120 // Can be used in other ctors.
122 _Enable_default_constructor(_Enable_default_constructor_tag
) { }
125 template<typename _Tag
>
126 struct _Enable_destructor
<false, _Tag
>
127 { ~_Enable_destructor() noexcept
= delete; };
129 template<typename _Tag
>
130 struct _Enable_copy_move
<false, true, true, true, _Tag
>
132 constexpr _Enable_copy_move() noexcept
= default;
133 constexpr _Enable_copy_move(_Enable_copy_move
const&) noexcept
= delete;
134 constexpr _Enable_copy_move(_Enable_copy_move
&&) noexcept
= default;
136 operator=(_Enable_copy_move
const&) noexcept
= default;
138 operator=(_Enable_copy_move
&&) noexcept
= default;
141 template<typename _Tag
>
142 struct _Enable_copy_move
<true, false, true, true, _Tag
>
144 constexpr _Enable_copy_move() noexcept
= default;
145 constexpr _Enable_copy_move(_Enable_copy_move
const&) noexcept
= default;
146 constexpr _Enable_copy_move(_Enable_copy_move
&&) noexcept
= default;
148 operator=(_Enable_copy_move
const&) noexcept
= delete;
150 operator=(_Enable_copy_move
&&) noexcept
= default;
153 template<typename _Tag
>
154 struct _Enable_copy_move
<false, false, true, true, _Tag
>
156 constexpr _Enable_copy_move() noexcept
= default;
157 constexpr _Enable_copy_move(_Enable_copy_move
const&) noexcept
= delete;
158 constexpr _Enable_copy_move(_Enable_copy_move
&&) noexcept
= default;
160 operator=(_Enable_copy_move
const&) noexcept
= delete;
162 operator=(_Enable_copy_move
&&) noexcept
= default;
165 template<typename _Tag
>
166 struct _Enable_copy_move
<true, true, false, true, _Tag
>
168 constexpr _Enable_copy_move() noexcept
= default;
169 constexpr _Enable_copy_move(_Enable_copy_move
const&) noexcept
= default;
170 constexpr _Enable_copy_move(_Enable_copy_move
&&) noexcept
= delete;
172 operator=(_Enable_copy_move
const&) noexcept
= default;
174 operator=(_Enable_copy_move
&&) noexcept
= default;
177 template<typename _Tag
>
178 struct _Enable_copy_move
<false, true, false, true, _Tag
>
180 constexpr _Enable_copy_move() noexcept
= default;
181 constexpr _Enable_copy_move(_Enable_copy_move
const&) noexcept
= delete;
182 constexpr _Enable_copy_move(_Enable_copy_move
&&) noexcept
= delete;
184 operator=(_Enable_copy_move
const&) noexcept
= default;
186 operator=(_Enable_copy_move
&&) noexcept
= default;
189 template<typename _Tag
>
190 struct _Enable_copy_move
<true, false, false, true, _Tag
>
192 constexpr _Enable_copy_move() noexcept
= default;
193 constexpr _Enable_copy_move(_Enable_copy_move
const&) noexcept
= default;
194 constexpr _Enable_copy_move(_Enable_copy_move
&&) noexcept
= delete;
196 operator=(_Enable_copy_move
const&) noexcept
= delete;
198 operator=(_Enable_copy_move
&&) noexcept
= default;
201 template<typename _Tag
>
202 struct _Enable_copy_move
<false, false, false, true, _Tag
>
204 constexpr _Enable_copy_move() noexcept
= default;
205 constexpr _Enable_copy_move(_Enable_copy_move
const&) noexcept
= delete;
206 constexpr _Enable_copy_move(_Enable_copy_move
&&) noexcept
= delete;
208 operator=(_Enable_copy_move
const&) noexcept
= delete;
210 operator=(_Enable_copy_move
&&) noexcept
= default;
213 template<typename _Tag
>
214 struct _Enable_copy_move
<true, true, true, false, _Tag
>
216 constexpr _Enable_copy_move() noexcept
= default;
217 constexpr _Enable_copy_move(_Enable_copy_move
const&) noexcept
= default;
218 constexpr _Enable_copy_move(_Enable_copy_move
&&) noexcept
= default;
220 operator=(_Enable_copy_move
const&) noexcept
= default;
222 operator=(_Enable_copy_move
&&) noexcept
= delete;
225 template<typename _Tag
>
226 struct _Enable_copy_move
<false, true, true, false, _Tag
>
228 constexpr _Enable_copy_move() noexcept
= default;
229 constexpr _Enable_copy_move(_Enable_copy_move
const&) noexcept
= delete;
230 constexpr _Enable_copy_move(_Enable_copy_move
&&) noexcept
= default;
232 operator=(_Enable_copy_move
const&) noexcept
= default;
234 operator=(_Enable_copy_move
&&) noexcept
= delete;
237 template<typename _Tag
>
238 struct _Enable_copy_move
<true, false, true, false, _Tag
>
240 constexpr _Enable_copy_move() noexcept
= default;
241 constexpr _Enable_copy_move(_Enable_copy_move
const&) noexcept
= default;
242 constexpr _Enable_copy_move(_Enable_copy_move
&&) noexcept
= default;
244 operator=(_Enable_copy_move
const&) noexcept
= delete;
246 operator=(_Enable_copy_move
&&) noexcept
= delete;
249 template<typename _Tag
>
250 struct _Enable_copy_move
<false, false, true, false, _Tag
>
252 constexpr _Enable_copy_move() noexcept
= default;
253 constexpr _Enable_copy_move(_Enable_copy_move
const&) noexcept
= delete;
254 constexpr _Enable_copy_move(_Enable_copy_move
&&) noexcept
= default;
256 operator=(_Enable_copy_move
const&) noexcept
= delete;
258 operator=(_Enable_copy_move
&&) noexcept
= delete;
261 template<typename _Tag
>
262 struct _Enable_copy_move
<true, true, false, false, _Tag
>
264 constexpr _Enable_copy_move() noexcept
= default;
265 constexpr _Enable_copy_move(_Enable_copy_move
const&) noexcept
= default;
266 constexpr _Enable_copy_move(_Enable_copy_move
&&) noexcept
= delete;
268 operator=(_Enable_copy_move
const&) noexcept
= default;
270 operator=(_Enable_copy_move
&&) noexcept
= delete;
273 template<typename _Tag
>
274 struct _Enable_copy_move
<false, true, false, false, _Tag
>
276 constexpr _Enable_copy_move() noexcept
= default;
277 constexpr _Enable_copy_move(_Enable_copy_move
const&) noexcept
= delete;
278 constexpr _Enable_copy_move(_Enable_copy_move
&&) noexcept
= delete;
280 operator=(_Enable_copy_move
const&) noexcept
= default;
282 operator=(_Enable_copy_move
&&) noexcept
= delete;
285 template<typename _Tag
>
286 struct _Enable_copy_move
<true, false, false, false, _Tag
>
288 constexpr _Enable_copy_move() noexcept
= default;
289 constexpr _Enable_copy_move(_Enable_copy_move
const&) noexcept
= default;
290 constexpr _Enable_copy_move(_Enable_copy_move
&&) noexcept
= delete;
292 operator=(_Enable_copy_move
const&) noexcept
= delete;
294 operator=(_Enable_copy_move
&&) noexcept
= delete;
297 template<typename _Tag
>
298 struct _Enable_copy_move
<false, false, false, false, _Tag
>
300 constexpr _Enable_copy_move() noexcept
= default;
301 constexpr _Enable_copy_move(_Enable_copy_move
const&) noexcept
= delete;
302 constexpr _Enable_copy_move(_Enable_copy_move
&&) noexcept
= delete;
304 operator=(_Enable_copy_move
const&) noexcept
= delete;
306 operator=(_Enable_copy_move
&&) noexcept
= delete;
309 _GLIBCXX_END_NAMESPACE_VERSION
312 #endif // _ENABLE_SPECIAL_MEMBERS_H