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