1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
// <extptr_allocator.h> -*- C++ -*-
// Copyright (C) 2008-2015 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/**
* @file ext/extptr_allocator.h
* This file is a GNU extension to the Standard C++ Library.
*
* @author Bob Walters
*
* An example allocator which uses an alternative pointer type from
* bits/pointer.h. Supports test cases which confirm container support
* for alternative pointers.
*/
#ifndef _EXTPTR_ALLOCATOR_H
#define _EXTPTR_ALLOCATOR_H 1
#include <memory>
#include <ext/numeric_traits.h>
#include <ext/pointer.h>
namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/**
* @brief An example allocator which uses a non-standard pointer type.
* @ingroup allocators
*
* This allocator specifies that containers use a 'relative pointer' as it's
* pointer type. (See ext/pointer.h) Memory allocation in this example
* is still performed using std::allocator.
*/
template<typename _Tp>
class _ExtPtr_allocator
{
public:
typedef std::size_t size_type;
typedef std::ptrdiff_t difference_type;
// Note the non-standard pointer types.
typedef _Pointer_adapter<_Relative_pointer_impl<_Tp> > pointer;
typedef _Pointer_adapter<_Relative_pointer_impl<const _Tp> >
const_pointer;
typedef _Tp& reference;
typedef const _Tp& const_reference;
typedef _Tp value_type;
template<typename _Up>
struct rebind
{ typedef _ExtPtr_allocator<_Up> other; };
_ExtPtr_allocator() _GLIBCXX_USE_NOEXCEPT
: _M_real_alloc() { }
_ExtPtr_allocator(const _ExtPtr_allocator& __rarg) _GLIBCXX_USE_NOEXCEPT
: _M_real_alloc(__rarg._M_real_alloc) { }
template<typename _Up>
_ExtPtr_allocator(const _ExtPtr_allocator<_Up>& __rarg)
_GLIBCXX_USE_NOEXCEPT
: _M_real_alloc(__rarg._M_getUnderlyingImp()) { }
~_ExtPtr_allocator() _GLIBCXX_USE_NOEXCEPT
{ }
pointer address(reference __x) const _GLIBCXX_NOEXCEPT
{ return std::__addressof(__x); }
const_pointer address(const_reference __x) const _GLIBCXX_NOEXCEPT
{ return std::__addressof(__x); }
pointer allocate(size_type __n, void* __hint = 0)
{ return _M_real_alloc.allocate(__n,__hint); }
void deallocate(pointer __p, size_type __n)
{ _M_real_alloc.deallocate(__p.get(), __n); }
size_type max_size() const _GLIBCXX_USE_NOEXCEPT
{ return __numeric_traits<size_type>::__max / sizeof(_Tp); }
#if __cplusplus >= 201103L
template<typename _Up, typename... _Args>
void
construct(_Up* __p, _Args&&... __args)
{ ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
template<typename... _Args>
void
construct(pointer __p, _Args&&... __args)
{ construct(__p.get(), std::forward<_Args>(__args)...); }
template<typename _Up>
void
destroy(_Up* __p)
{ __p->~_Up(); }
void destroy(pointer __p)
{ destroy(__p.get()); }
#else
void construct(pointer __p, const _Tp& __val)
{ ::new(__p.get()) _Tp(__val); }
void destroy(pointer __p)
{ __p->~_Tp(); }
#endif
template<typename _Up>
inline bool
operator==(const _ExtPtr_allocator<_Up>& __rarg)
{ return _M_real_alloc == __rarg._M_getUnderlyingImp(); }
inline bool
operator==(const _ExtPtr_allocator& __rarg)
{ return _M_real_alloc == __rarg._M_real_alloc; }
template<typename _Up>
inline bool
operator!=(const _ExtPtr_allocator<_Up>& __rarg)
{ return _M_real_alloc != __rarg._M_getUnderlyingImp(); }
inline bool
operator!=(const _ExtPtr_allocator& __rarg)
{ return _M_real_alloc != __rarg._M_real_alloc; }
template<typename _Up>
inline friend void
swap(_ExtPtr_allocator<_Up>&, _ExtPtr_allocator<_Up>&);
// A method specific to this implementation.
const std::allocator<_Tp>&
_M_getUnderlyingImp() const
{ return _M_real_alloc; }
private:
std::allocator<_Tp> _M_real_alloc;
};
// _ExtPtr_allocator<void> specialization.
template<>
class _ExtPtr_allocator<void>
{
public:
typedef std::size_t size_type;
typedef std::ptrdiff_t difference_type;
typedef void value_type;
// Note the non-standard pointer types
typedef _Pointer_adapter<_Relative_pointer_impl<void> > pointer;
typedef _Pointer_adapter<_Relative_pointer_impl<const void> >
const_pointer;
template<typename _Up>
struct rebind
{ typedef _ExtPtr_allocator<_Up> other; };
private:
std::allocator<void> _M_real_alloc;
};
template<typename _Tp>
inline void
swap(_ExtPtr_allocator<_Tp>& __larg, _ExtPtr_allocator<_Tp>& __rarg)
{
std::allocator<_Tp> __tmp( __rarg._M_real_alloc );
__rarg._M_real_alloc = __larg._M_real_alloc;
__larg._M_real_alloc = __tmp;
}
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif /* _EXTPTR_ALLOCATOR_H */
|
