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1 : // Allocator that wraps operator new -*- C++ -*-
2 :
3 : // Copyright (C) 2001-2017 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 ext/new_allocator.h
26 : * This file is a GNU extension to the Standard C++ Library.
27 : */
28 :
29 : #ifndef _NEW_ALLOCATOR_H
30 : #define _NEW_ALLOCATOR_H 1
31 :
32 : #include <bits/c++config.h>
33 : #include <new>
34 : #include <bits/functexcept.h>
35 : #include <bits/move.h>
36 : #if __cplusplus >= 201103L
37 : #include <type_traits>
38 : #endif
39 :
40 : namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
41 : {
42 : _GLIBCXX_BEGIN_NAMESPACE_VERSION
43 :
44 : using std::size_t;
45 : using std::ptrdiff_t;
46 :
47 : /**
48 : * @brief An allocator that uses global new, as per [20.4].
49 : * @ingroup allocators
50 : *
51 : * This is precisely the allocator defined in the C++ Standard.
52 : * - all allocation calls operator new
53 : * - all deallocation calls operator delete
54 : *
55 : * @tparam _Tp Type of allocated object.
56 : */
57 : template<typename _Tp>
58 : class new_allocator
59 : {
60 : public:
61 : typedef size_t size_type;
62 : typedef ptrdiff_t difference_type;
63 : typedef _Tp* pointer;
64 : typedef const _Tp* const_pointer;
65 : typedef _Tp& reference;
66 : typedef const _Tp& const_reference;
67 : typedef _Tp value_type;
68 :
69 : template<typename _Tp1>
70 : struct rebind
71 : { typedef new_allocator<_Tp1> other; };
72 :
73 : #if __cplusplus >= 201103L
74 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
75 : // 2103. propagate_on_container_move_assignment
76 : typedef std::true_type propagate_on_container_move_assignment;
77 : #endif
78 :
79 : new_allocator() _GLIBCXX_USE_NOEXCEPT { }
80 :
81 : new_allocator(const new_allocator&) _GLIBCXX_USE_NOEXCEPT { }
82 :
83 : template<typename _Tp1>
84 : new_allocator(const new_allocator<_Tp1>&) _GLIBCXX_USE_NOEXCEPT { }
85 :
86 : ~new_allocator() _GLIBCXX_USE_NOEXCEPT { }
87 :
88 : pointer
89 : address(reference __x) const _GLIBCXX_NOEXCEPT
90 : { return std::__addressof(__x); }
91 :
92 : const_pointer
93 : address(const_reference __x) const _GLIBCXX_NOEXCEPT
94 : { return std::__addressof(__x); }
95 :
96 : // NB: __n is permitted to be 0. The C++ standard says nothing
97 : // about what the return value is when __n == 0.
98 : pointer
99 : allocate(size_type __n, const void* = static_cast<const void*>(0))
100 : {
101 132 : if (__n > this->max_size())
102 : std::__throw_bad_alloc();
103 :
104 : #if __cpp_aligned_new
105 : if (alignof(_Tp) > __STDCPP_DEFAULT_NEW_ALIGNMENT__)
106 : {
107 : std::align_val_t __al = std::align_val_t(alignof(_Tp));
108 : return static_cast<_Tp*>(::operator new(__n * sizeof(_Tp), __al));
109 : }
110 : #endif
111 132 : return static_cast<_Tp*>(::operator new(__n * sizeof(_Tp)));
112 : }
113 :
114 : // __p is not permitted to be a null pointer.
115 : void
116 : deallocate(pointer __p, size_type)
117 : {
118 : #if __cpp_aligned_new
119 : if (alignof(_Tp) > __STDCPP_DEFAULT_NEW_ALIGNMENT__)
120 : {
121 : ::operator delete(__p, std::align_val_t(alignof(_Tp)));
122 : return;
123 : }
124 : #endif
125 790128 : ::operator delete(__p);
126 : }
127 :
128 : size_type
129 : max_size() const _GLIBCXX_USE_NOEXCEPT
130 : { return size_t(-1) / sizeof(_Tp); }
131 :
132 : #if __cplusplus >= 201103L
133 : template<typename _Up, typename... _Args>
134 : void
135 : construct(_Up* __p, _Args&&... __args)
136 132 : { ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
137 :
138 : template<typename _Up>
139 : void
140 132 : destroy(_Up* __p) { __p->~_Up(); }
141 : #else
142 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
143 : // 402. wrong new expression in [some_] allocator::construct
144 : void
145 : construct(pointer __p, const _Tp& __val)
146 : { ::new((void *)__p) _Tp(__val); }
147 :
148 : void
149 : destroy(pointer __p) { __p->~_Tp(); }
150 : #endif
151 : };
152 :
153 : template<typename _Tp>
154 : inline bool
155 : operator==(const new_allocator<_Tp>&, const new_allocator<_Tp>&)
156 : { return true; }
157 :
158 : template<typename _Tp>
159 : inline bool
160 : operator!=(const new_allocator<_Tp>&, const new_allocator<_Tp>&)
161 : { return false; }
162 :
163 : _GLIBCXX_END_NAMESPACE_VERSION
164 : } // namespace
165 :
166 : #endif
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