1// nonstandard construct and destroy functions -*- C++ -*-
2
3// Copyright (C) 2001-2019 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/*
26 *
27 * Copyright (c) 1994
28 * Hewlett-Packard Company
29 *
30 * Permission to use, copy, modify, distribute and sell this software
31 * and its documentation for any purpose is hereby granted without fee,
32 * provided that the above copyright notice appear in all copies and
33 * that both that copyright notice and this permission notice appear
34 * in supporting documentation. Hewlett-Packard Company makes no
35 * representations about the suitability of this software for any
36 * purpose. It is provided "as is" without express or implied warranty.
37 *
38 *
39 * Copyright (c) 1996,1997
40 * Silicon Graphics Computer Systems, Inc.
41 *
42 * Permission to use, copy, modify, distribute and sell this software
43 * and its documentation for any purpose is hereby granted without fee,
44 * provided that the above copyright notice appear in all copies and
45 * that both that copyright notice and this permission notice appear
46 * in supporting documentation. Silicon Graphics makes no
47 * representations about the suitability of this software for any
48 * purpose. It is provided "as is" without express or implied warranty.
49 */
50
51/** @file bits/stl_construct.h
52 * This is an internal header file, included by other library headers.
53 * Do not attempt to use it directly. @headername{memory}
54 */
55
56#ifndef _STL_CONSTRUCT_H
57#define _STL_CONSTRUCT_H 1
58
59#include <new>
60#include <bits/move.h>
61#include <ext/alloc_traits.h>
62
63namespace std _GLIBCXX_VISIBILITY(default)
64{
65_GLIBCXX_BEGIN_NAMESPACE_VERSION
66
67 /**
68 * Constructs an object in existing memory by invoking an allocated
69 * object's constructor with an initializer.
70 */
71#if __cplusplus >= 201103L
72 template<typename _T1, typename... _Args>
73 inline void
74 _Construct(_T1* __p, _Args&&... __args)
75 { ::new(static_cast<void*>(__p)) _T1(std::forward<_Args>(__args)...); }
76#else
77 template<typename _T1, typename _T2>
78 inline void
79 _Construct(_T1* __p, const _T2& __value)
80 {
81 // _GLIBCXX_RESOLVE_LIB_DEFECTS
82 // 402. wrong new expression in [some_]allocator::construct
83 ::new(static_cast<void*>(__p)) _T1(__value);
84 }
85#endif
86
87 template<typename _T1>
88 inline void
89 _Construct_novalue(_T1* __p)
90 { ::new(static_cast<void*>(__p)) _T1; }
91
92 /**
93 * Destroy the object pointed to by a pointer type.
94 */
95 template<typename _Tp>
96 inline void
97 _Destroy(_Tp* __pointer)
98 { __pointer->~_Tp(); }
99
100 template<bool>
101 struct _Destroy_aux
102 {
103 template<typename _ForwardIterator>
104 static void
105 __destroy(_ForwardIterator __first, _ForwardIterator __last)
106 {
107 for (; __first != __last; ++__first)
108 std::_Destroy(std::__addressof(*__first));
109 }
110 };
111
112 template<>
113 struct _Destroy_aux<true>
114 {
115 template<typename _ForwardIterator>
116 static void
117 __destroy(_ForwardIterator, _ForwardIterator) { }
118 };
119
120 /**
121 * Destroy a range of objects. If the value_type of the object has
122 * a trivial destructor, the compiler should optimize all of this
123 * away, otherwise the objects' destructors must be invoked.
124 */
125 template<typename _ForwardIterator>
126 inline void
127 _Destroy(_ForwardIterator __first, _ForwardIterator __last)
128 {
129 typedef typename iterator_traits<_ForwardIterator>::value_type
130 _Value_type;
131#if __cplusplus >= 201103L
132 // A deleted destructor is trivial, this ensures we reject such types:
133 static_assert(is_destructible<_Value_type>::value,
134 "value type is destructible");
135#endif
136 std::_Destroy_aux<__has_trivial_destructor(_Value_type)>::
137 __destroy(__first, __last);
138 }
139
140 template<bool>
141 struct _Destroy_n_aux
142 {
143 template<typename _ForwardIterator, typename _Size>
144 static _ForwardIterator
145 __destroy_n(_ForwardIterator __first, _Size __count)
146 {
147 for (; __count > 0; (void)++__first, --__count)
148 std::_Destroy(std::__addressof(*__first));
149 return __first;
150 }
151 };
152
153 template<>
154 struct _Destroy_n_aux<true>
155 {
156 template<typename _ForwardIterator, typename _Size>
157 static _ForwardIterator
158 __destroy_n(_ForwardIterator __first, _Size __count)
159 {
160 std::advance(__first, __count);
161 return __first;
162 }
163 };
164
165 /**
166 * Destroy a range of objects. If the value_type of the object has
167 * a trivial destructor, the compiler should optimize all of this
168 * away, otherwise the objects' destructors must be invoked.
169 */
170 template<typename _ForwardIterator, typename _Size>
171 inline _ForwardIterator
172 _Destroy_n(_ForwardIterator __first, _Size __count)
173 {
174 typedef typename iterator_traits<_ForwardIterator>::value_type
175 _Value_type;
176#if __cplusplus >= 201103L
177 // A deleted destructor is trivial, this ensures we reject such types:
178 static_assert(is_destructible<_Value_type>::value,
179 "value type is destructible");
180#endif
181 return std::_Destroy_n_aux<__has_trivial_destructor(_Value_type)>::
182 __destroy_n(__first, __count);
183 }
184
185 /**
186 * Destroy a range of objects using the supplied allocator. For
187 * nondefault allocators we do not optimize away invocation of
188 * destroy() even if _Tp has a trivial destructor.
189 */
190
191 template<typename _ForwardIterator, typename _Allocator>
192 void
193 _Destroy(_ForwardIterator __first, _ForwardIterator __last,
194 _Allocator& __alloc)
195 {
196 typedef __gnu_cxx::__alloc_traits<_Allocator> __traits;
197 for (; __first != __last; ++__first)
198 __traits::destroy(__alloc, std::__addressof(*__first));
199 }
200
201 template<typename _ForwardIterator, typename _Tp>
202 inline void
203 _Destroy(_ForwardIterator __first, _ForwardIterator __last,
204 allocator<_Tp>&)
205 {
206 _Destroy(__first, __last);
207 }
208
209#if __cplusplus > 201402L
210 template <typename _Tp>
211 inline void
212 destroy_at(_Tp* __location)
213 {
214 std::_Destroy(__location);
215 }
216
217 template <typename _ForwardIterator>
218 inline void
219 destroy(_ForwardIterator __first, _ForwardIterator __last)
220 {
221 std::_Destroy(__first, __last);
222 }
223
224 template <typename _ForwardIterator, typename _Size>
225 inline _ForwardIterator
226 destroy_n(_ForwardIterator __first, _Size __count)
227 {
228 return std::_Destroy_n(__first, __count);
229 }
230#endif
231
232_GLIBCXX_END_NAMESPACE_VERSION
233} // namespace std
234
235#endif /* _STL_CONSTRUCT_H */
236
237