libstdc++
memory
Go to the documentation of this file.
1 // <memory> -*- C++ -*-
2 
3 // Copyright (C) 2001-2025 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  * Copyright (c) 1997-1999
27  * Silicon Graphics Computer Systems, Inc.
28  *
29  * Permission to use, copy, modify, distribute and sell this software
30  * and its documentation for any purpose is hereby granted without fee,
31  * provided that the above copyright notice appear in all copies and
32  * that both that copyright notice and this permission notice appear
33  * in supporting documentation. Silicon Graphics makes no
34  * representations about the suitability of this software for any
35  * purpose. It is provided "as is" without express or implied warranty.
36  *
37  */
38 
39 /** @file include/memory
40  * This is a Standard C++ Library header.
41  * @ingroup memory
42  */
43 
44 #ifndef _GLIBCXX_MEMORY
45 #define _GLIBCXX_MEMORY 1
46 
47 #ifdef _GLIBCXX_SYSHDR
48 #pragma GCC system_header
49 #endif
50 
51 /**
52  * @defgroup memory Memory
53  * @ingroup utilities
54  *
55  * Components for memory allocation, deallocation, and management.
56  */
57 
58 /**
59  * @defgroup pointer_abstractions Pointer Abstractions
60  * @ingroup memory
61  *
62  * Smart pointers, etc.
63  */
64 
65 #include <bits/memoryfwd.h>
66 #if _GLIBCXX_HOSTED
67 # include <bits/allocator.h>
68 # include <bits/stl_tempbuf.h>
69 #endif
70 #include <bits/stl_construct.h>
71 #include <bits/stl_uninitialized.h>
72 #include <bits/stl_raw_storage_iter.h>
73 
74 #if __cplusplus >= 201103L
75 # include <type_traits>
76 # include <bits/align.h>
77 # include <bits/uses_allocator.h>
78 # include <bits/alloc_traits.h>
79 # include <debug/debug.h>
80 # include <bits/unique_ptr.h>
81 # if _GLIBCXX_HOSTED
82 # include <bits/shared_ptr.h>
83 # include <bits/shared_ptr_atomic.h>
84 # endif
85 #endif
86 
87 #if __cplusplus < 201103L || _GLIBCXX_USE_DEPRECATED
88 # include <backward/auto_ptr.h>
89 #endif
90 
91 #if __cplusplus > 201703L
92 # include <bits/ranges_uninitialized.h>
93 # include <bits/uses_allocator_args.h>
94 #endif
95 
96 #if __cplusplus > 202002L
97 # include <bits/out_ptr.h>
98 #endif
99 
100 #define __glibcxx_want_addressof_constexpr
101 #define __glibcxx_want_allocator_traits_is_always_equal
102 #define __glibcxx_want_assume_aligned
103 #define __glibcxx_want_atomic_shared_ptr
104 #define __glibcxx_want_atomic_value_initialization
105 #define __glibcxx_want_constexpr_dynamic_alloc
106 #define __glibcxx_want_constexpr_memory
107 #define __glibcxx_want_enable_shared_from_this
108 #define __glibcxx_want_make_unique
109 #define __glibcxx_want_out_ptr
110 #define __glibcxx_want_parallel_algorithm
111 #define __glibcxx_want_ranges
112 #define __glibcxx_want_raw_memory_algorithms
113 #define __glibcxx_want_shared_ptr_arrays
114 #define __glibcxx_want_shared_ptr_weak_type
115 #define __glibcxx_want_smart_ptr_for_overwrite
116 #define __glibcxx_want_to_address
117 #define __glibcxx_want_transparent_operators
118 #include <bits/version.h>
119 
120 #if __cplusplus >= 201103L && __cplusplus <= 202002L && _GLIBCXX_HOSTED
121 namespace std _GLIBCXX_VISIBILITY(default)
122 {
123 _GLIBCXX_BEGIN_NAMESPACE_VERSION
124 
125 /** @defgroup ptr_safety Pointer Safety and Garbage Collection
126  * @ingroup memory
127  *
128  * Utilities to assist with garbage collection in an implementation
129  * that supports <em>strict pointer safety</em>.
130  * This implementation only supports <em>relaxed pointer safety</em>
131  * and so these functions have no effect.
132  *
133  * C++11 20.6.4 [util.dynamic.safety], Pointer safety
134  *
135  * @{
136  */
137 
138 /// Constants representing the different types of pointer safety.
139 enum class pointer_safety { relaxed, preferred, strict };
140 
141 /// Inform a garbage collector that an object is still in use.
142 inline void
143 declare_reachable(void*) { }
144 
145 /// Unregister an object previously registered with declare_reachable.
146 template <typename _Tp>
147  inline _Tp*
148  undeclare_reachable(_Tp* __p) { return __p; }
149 
150 /// Inform a garbage collector that a region of memory need not be traced.
151 inline void
152 declare_no_pointers(char*, size_t) { }
153 
154 /// Unregister a range previously registered with declare_no_pointers.
155 inline void
156 undeclare_no_pointers(char*, size_t) { }
157 
158 /// The type of pointer safety supported by the implementation.
159 inline pointer_safety
160 get_pointer_safety() noexcept { return pointer_safety::relaxed; }
161 /// @}
162 
163 _GLIBCXX_END_NAMESPACE_VERSION
164 } // namespace
165 #endif // C++11 to C++20
166 
167 #ifdef __cpp_lib_parallel_algorithm // C++ >= 17 && HOSTED
168 // Parallel STL algorithms
169 # if _PSTL_EXECUTION_POLICIES_DEFINED
170 // If <execution> has already been included, pull in implementations
171 # include <pstl/glue_memory_impl.h>
172 # else
173 // Otherwise just pull in forward declarations
174 # include <pstl/glue_memory_defs.h>
175 # endif
176 #endif // __cpp_lib_parallel_algorithm
177 
178 #endif /* _GLIBCXX_MEMORY */