1 // Allocator that wraps "C" malloc -*- C++ -*-
3 // Copyright (C) 2001-2018 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 ext/malloc_allocator.h
26 * This file is a GNU extension to the Standard C++ Library.
29 #ifndef _MALLOC_ALLOCATOR_H
30 #define _MALLOC_ALLOCATOR_H 1
35 #include <bits/functexcept.h>
36 #include <bits/move.h>
37 #if __cplusplus >= 201103L
38 #include <type_traits>
41 namespace __gnu_cxx
_GLIBCXX_VISIBILITY(default)
43 _GLIBCXX_BEGIN_NAMESPACE_VERSION
49 * @brief An allocator that uses malloc.
52 * This is precisely the allocator defined in the C++ Standard.
53 * - all allocation calls malloc
54 * - all deallocation calls free
56 template<typename _Tp
>
57 class malloc_allocator
60 typedef size_t size_type
;
61 typedef ptrdiff_t difference_type
;
63 typedef const _Tp
* const_pointer
;
64 typedef _Tp
& reference
;
65 typedef const _Tp
& const_reference
;
66 typedef _Tp value_type
;
68 template<typename _Tp1
>
70 { typedef malloc_allocator
<_Tp1
> other
; };
72 #if __cplusplus >= 201103L
73 // _GLIBCXX_RESOLVE_LIB_DEFECTS
74 // 2103. propagate_on_container_move_assignment
75 typedef std::true_type propagate_on_container_move_assignment
;
78 malloc_allocator() _GLIBCXX_USE_NOEXCEPT
{ }
80 malloc_allocator(const malloc_allocator
&) _GLIBCXX_USE_NOEXCEPT
{ }
82 template<typename _Tp1
>
83 malloc_allocator(const malloc_allocator
<_Tp1
>&)
84 _GLIBCXX_USE_NOEXCEPT
{ }
86 ~malloc_allocator() _GLIBCXX_USE_NOEXCEPT
{ }
89 address(reference __x
) const _GLIBCXX_NOEXCEPT
90 { return std::__addressof(__x
); }
93 address(const_reference __x
) const _GLIBCXX_NOEXCEPT
94 { return std::__addressof(__x
); }
96 // NB: __n is permitted to be 0. The C++ standard says nothing
97 // about what the return value is when __n == 0.
99 allocate(size_type __n
, const void* = 0)
101 if (__n
> this->max_size())
102 std::__throw_bad_alloc();
105 #if __cpp_aligned_new
106 #if __cplusplus > 201402L && _GLIBCXX_HAVE_ALIGNED_ALLOC
107 if (alignof(_Tp
) > alignof(std::max_align_t
))
109 __ret
= static_cast<_Tp
*>(::aligned_alloc(alignof(_Tp
),
113 # define _GLIBCXX_CHECK_MALLOC_RESULT
117 __ret
= static_cast<_Tp
*>(std::malloc(__n
* sizeof(_Tp
)));
119 std::__throw_bad_alloc();
120 #ifdef _GLIBCXX_CHECK_MALLOC_RESULT
121 #undef _GLIBCXX_CHECK_MALLOC_RESULT
122 if (reinterpret_cast<std::size_t>(__ret
) % alignof(_Tp
))
124 // Memory returned by malloc is not suitably aligned for _Tp.
125 deallocate(__ret
, __n
);
126 std::__throw_bad_alloc();
132 // __p is not permitted to be a null pointer.
134 deallocate(pointer __p
, size_type
)
135 { std::free(static_cast<void*>(__p
)); }
138 max_size() const _GLIBCXX_USE_NOEXCEPT
139 { return size_t(-1) / sizeof(_Tp
); }
141 #if __cplusplus >= 201103L
142 template<typename _Up
, typename
... _Args
>
144 construct(_Up
* __p
, _Args
&&... __args
)
145 { ::new((void *)__p
) _Up(std::forward
<_Args
>(__args
)...); }
147 template<typename _Up
>
149 destroy(_Up
* __p
) { __p
->~_Up(); }
151 // _GLIBCXX_RESOLVE_LIB_DEFECTS
152 // 402. wrong new expression in [some_] allocator::construct
154 construct(pointer __p
, const _Tp
& __val
)
155 { ::new((void *)__p
) value_type(__val
); }
158 destroy(pointer __p
) { __p
->~_Tp(); }
162 template<typename _Tp
>
164 operator==(const malloc_allocator
<_Tp
>&, const malloc_allocator
<_Tp
>&)
167 template<typename _Tp
>
169 operator!=(const malloc_allocator
<_Tp
>&, const malloc_allocator
<_Tp
>&)
172 _GLIBCXX_END_NAMESPACE_VERSION