libstdc++
scoped_allocator
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1 // <scoped_allocator> -*- C++ -*-
2 
3 // Copyright (C) 2011, 2012 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 include/scoped_allocator
26  * This is a Standard C++ Library header.
27  */
28 
29 #ifndef _SCOPED_ALLOCATOR
30 #define _SCOPED_ALLOCATOR 1
31 
32 #pragma GCC system_header
33 
34 #ifndef __GXX_EXPERIMENTAL_CXX0X__
35 # include <bits/c++0x_warning.h>
36 #else
37 
38 #include <utility>
39 #include <tuple>
40 #include <bits/alloc_traits.h>
41 
42 namespace std _GLIBCXX_VISIBILITY(default)
43 {
44 _GLIBCXX_BEGIN_NAMESPACE_VERSION
45 
46  template<template<typename> class _Pred, typename... _Allocs>
47  struct __any_of;
48 
49  template<template<typename> class _Pred, typename _Alloc, typename... _Allocs>
50  struct __any_of<_Pred, _Alloc, _Allocs...>
51  : __or_<_Pred<_Alloc>, __any_of<_Pred, _Allocs...>>
52  { };
53 
54  template<template<typename> class _Pred, typename _Alloc>
55  struct __any_of<_Pred, _Alloc>
56  : _Pred<_Alloc>
57  { };
58 
59  /**
60  * @addtogroup allocators
61  * @{
62  */
63 
64  template<typename _Alloc>
65  struct __propagate_on_copy
66  : allocator_traits<_Alloc>::propagate_on_container_copy_assignment
67  { };
68  template<typename _Alloc>
69  struct __propagate_on_move
70  : allocator_traits<_Alloc>::propagate_on_container_move_assignment
71  { };
72  template<typename _Alloc>
73  struct __propagate_on_swap
74  : allocator_traits<_Alloc>::propagate_on_container_swap
75  { };
76 
77 
78  template<typename _Alloc>
79  inline auto
80  __do_outermost(_Alloc& __a, _Alloc*) -> decltype(__a.outer_allocator())
81  { return __a.outer_allocator(); }
82 
83  template<typename _Alloc>
84  inline _Alloc&
85  __do_outermost(_Alloc& __a, ...)
86  { return __a; }
87 
88  template<typename _Alloc>
89  inline auto
90  __outermost(_Alloc& __a) -> decltype(__do_outermost(__a, &__a))
91  { return __do_outermost(__a, &__a); }
92 
93  template<typename _OuterAlloc, typename... _InnerAllocs>
94  class scoped_allocator_adaptor;
95 
96  template<typename...>
97  struct __inner_type_impl;
98 
99  template<typename _Outer>
100  struct __inner_type_impl<_Outer>
101  {
102  typedef scoped_allocator_adaptor<_Outer> __type;
103 
104  __inner_type_impl() = default;
105  __inner_type_impl(const __inner_type_impl&) = default;
106  __inner_type_impl(__inner_type_impl&&) = default;
107 
108  template<typename _Alloc>
109  __inner_type_impl(const __inner_type_impl<_Alloc>& __other)
110  { }
111 
112  template<typename _Alloc>
113  __inner_type_impl(__inner_type_impl<_Alloc>&& __other)
114  { }
115 
116  __type&
117  _M_get(__type* __p) noexcept { return *__p; }
118 
119  const __type&
120  _M_get(const __type* __p) const noexcept { return *__p; }
121 
122  tuple<>
123  _M_tie() const noexcept { return tuple<>(); }
124 
125  bool
126  operator==(const __inner_type_impl&) const noexcept
127  { return true; }
128  };
129 
130  template<typename _Outer, typename _InnerHead, typename... _InnerTail>
131  struct __inner_type_impl<_Outer, _InnerHead, _InnerTail...>
132  {
133  typedef scoped_allocator_adaptor<_InnerHead, _InnerTail...> __type;
134 
135  __inner_type_impl() = default;
136  __inner_type_impl(const __inner_type_impl&) = default;
137  __inner_type_impl(__inner_type_impl&&) = default;
138 
139  template<typename... _Allocs>
140  __inner_type_impl(const __inner_type_impl<_Allocs...>& __other)
141  : _M_inner(__other._M_inner) { }
142 
143  template<typename... _Allocs>
144  __inner_type_impl(__inner_type_impl<_Allocs...>&& __other)
145  : _M_inner(std::move(__other._M_inner)) { }
146 
147  template<typename... _Args>
148  explicit
149  __inner_type_impl(_Args&&... __args)
150  : _M_inner(std::forward<_Args>(__args)...) { }
151 
152  __type&
153  _M_get(void*) noexcept { return _M_inner; }
154 
155  const __type&
156  _M_get(const void*) const noexcept { return _M_inner; }
157 
158  tuple<const _InnerHead&, const _InnerTail&...>
159  _M_tie() const noexcept
160  { return _M_inner._M_tie(); }
161 
162  bool
163  operator==(const __inner_type_impl& __other) const noexcept
164  { return _M_inner == __other._M_inner; }
165 
166  private:
167  template<typename...> friend class __inner_type_impl;
168  template<typename, typename...> friend class scoped_allocator_adaptor;
169 
170  __type _M_inner;
171  };
172 
173  /// Primary class template.
174  template<typename _OuterAlloc, typename... _InnerAllocs>
175  class scoped_allocator_adaptor
176  : public _OuterAlloc
177  {
178  typedef allocator_traits<_OuterAlloc> __traits;
179 
180  typedef __inner_type_impl<_OuterAlloc, _InnerAllocs...> __inner_type;
181  __inner_type _M_inner;
182 
183  template<typename _Outer, typename... _Inner>
184  friend class scoped_allocator_adaptor;
185 
186  template<typename...>
187  friend class __inner_type_impl;
188 
189  tuple<const _OuterAlloc&, const _InnerAllocs&...>
190  _M_tie() const noexcept
191  { return std::tuple_cat(std::tie(outer_allocator()), _M_inner._M_tie()); }
192 
193 
194  template<typename _Tp, typename... _Args>
195  void
196  _M_construct(__uses_alloc0, _Tp* __p, _Args&&... __args)
197  {
198  auto& __outer = __outermost(*this);
199  typedef typename std::decay<decltype(__outer)>::type __outer_type;
200  typedef allocator_traits<__outer_type> __o_traits;
201  __o_traits::construct(__outer, __p, std::forward<_Args>(__args)...);
202  }
203 
204  typedef __uses_alloc1<typename __inner_type::__type> __uses_alloc1_;
205  typedef __uses_alloc2<typename __inner_type::__type> __uses_alloc2_;
206 
207  template<typename _Tp, typename... _Args>
208  void
209  _M_construct(__uses_alloc1_, _Tp* __p, _Args&&... __args)
210  {
211  auto& __outer = __outermost(*this);
212  typedef typename std::decay<decltype(__outer)>::type __outer_type;
213  typedef allocator_traits<__outer_type> __o_traits;
214  __o_traits::construct(__outer, __p, allocator_arg, inner_allocator(),
215  std::forward<_Args>(__args)...);
216  }
217 
218  template<typename _Tp, typename... _Args>
219  void
220  _M_construct(__uses_alloc2_, _Tp* __p, _Args&&... __args)
221  {
222  auto& __outer = __outermost(*this);
223  typedef typename std::decay<decltype(__outer)>::type __outer_type;
224  typedef allocator_traits<__outer_type> __o_traits;
225  __o_traits::construct(__outer, __p, std::forward<_Args>(__args)...,
226  inner_allocator());
227  }
228 
229  template<typename _Alloc>
230  static _Alloc
231  _S_select_on_copy(const _Alloc& __a)
232  {
233  typedef allocator_traits<_Alloc> __a_traits;
234  return __a_traits::select_on_container_copy_construction(__a);
235  }
236 
237  template<std::size_t... _Indices>
238  scoped_allocator_adaptor(tuple<const _OuterAlloc&,
239  const _InnerAllocs&...> __refs,
240  _Index_tuple<_Indices...>)
241  : _OuterAlloc(_S_select_on_copy(std::get<0>(__refs))),
242  _M_inner(_S_select_on_copy(std::get<_Indices+1>(__refs))...)
243  { }
244 
245  public:
246  typedef _OuterAlloc outer_allocator_type;
247  typedef typename __inner_type::__type inner_allocator_type;
248 
249  typedef typename __traits::value_type value_type;
250  typedef typename __traits::size_type size_type;
251  typedef typename __traits::difference_type difference_type;
252  typedef typename __traits::pointer pointer;
253  typedef typename __traits::const_pointer const_pointer;
254  typedef typename __traits::void_pointer void_pointer;
255  typedef typename __traits::const_void_pointer const_void_pointer;
256 
257  typedef typename conditional<
258  __any_of<__propagate_on_copy, _OuterAlloc, _InnerAllocs...>::value,
259  true_type, false_type>::type propagate_on_container_copy_assignment;
260  typedef typename conditional<
261  __any_of<__propagate_on_move, _OuterAlloc, _InnerAllocs...>::value,
262  true_type, false_type>::type propagate_on_container_move_assignment;
263  typedef typename conditional<
264  __any_of<__propagate_on_swap, _OuterAlloc, _InnerAllocs...>::value,
265  true_type, false_type>::type propagate_on_container_swap;
266 
267  template <class _Tp>
268  struct rebind
269  {
270  typedef scoped_allocator_adaptor<
271  typename __traits::template rebind_alloc<_Tp>,
272  _InnerAllocs...> other;
273  };
274 
275  scoped_allocator_adaptor() : _OuterAlloc(), _M_inner() { }
276 
277  template<typename _Outer2>
278  scoped_allocator_adaptor(_Outer2&& __outer,
279  const _InnerAllocs&... __inner)
280  : _OuterAlloc(std::forward<_Outer2>(__outer)),
281  _M_inner(__inner...)
282  { }
283 
284  scoped_allocator_adaptor(const scoped_allocator_adaptor& __other)
285  : _OuterAlloc(__other.outer_allocator()),
286  _M_inner(__other._M_inner)
287  { }
288 
289  scoped_allocator_adaptor(scoped_allocator_adaptor&& __other)
290  : _OuterAlloc(std::move(__other.outer_allocator())),
291  _M_inner(std::move(__other._M_inner))
292  { }
293 
294  template<typename _Outer2>
295  scoped_allocator_adaptor(
296  const scoped_allocator_adaptor<_Outer2, _InnerAllocs...>& __other)
297  : _OuterAlloc(__other.outer_allocator()),
298  _M_inner(__other._M_inner)
299  { }
300 
301  template<typename _Outer2>
302  scoped_allocator_adaptor(
303  scoped_allocator_adaptor<_Outer2, _InnerAllocs...>&& __other)
304  : _OuterAlloc(std::move(__other.outer_allocator())),
305  _M_inner(std::move(__other._M_inner))
306  { }
307 
308  inner_allocator_type& inner_allocator() noexcept
309  { return _M_inner._M_get(this); }
310 
311  const inner_allocator_type& inner_allocator() const noexcept
312  { return _M_inner._M_get(this); }
313 
314  outer_allocator_type& outer_allocator() noexcept
315  { return static_cast<_OuterAlloc&>(*this); }
316 
317  const outer_allocator_type& outer_allocator() const noexcept
318  { return static_cast<const _OuterAlloc&>(*this); }
319 
320  pointer allocate(size_type __n)
321  { return __traits::allocate(outer_allocator(), __n); }
322 
323  pointer allocate(size_type __n, const_void_pointer __hint)
324  { return __traits::allocate(outer_allocator(), __n, __hint); }
325 
326  void deallocate(pointer __p, size_type __n)
327  { return __traits::deallocate(outer_allocator(), __p, __n); }
328 
329  size_type max_size() const
330  { return __traits::max_size(outer_allocator()); }
331 
332  template<typename _Tp, typename... _Args>
333  void construct(_Tp* __p, _Args&&... __args)
334  {
335  auto& __inner = inner_allocator();
336  auto __use_tag
337  = __use_alloc<_Tp, inner_allocator_type, _Args...>(__inner);
338  _M_construct(__use_tag, __p, std::forward<_Args>(__args)...);
339  }
340 
341  // TODO: construct pairs
342 
343  template<typename _Tp>
344  void destroy(_Tp* __p)
345  {
346  auto& __outer = __outermost(*this);
347  typedef typename std::decay<decltype(__outer)>::type __outer_type;
348  allocator_traits<__outer_type>::destroy(__outer, __p);
349  }
350 
351  scoped_allocator_adaptor
352  select_on_container_copy_construction() const
353  {
354  typedef typename _Build_index_tuple<sizeof...(_InnerAllocs)>::__type
355  _Indices;
356  return scoped_allocator_adaptor(_M_tie(), _Indices());
357  }
358 
359  template <typename _OutA1, typename _OutA2, typename... _InA>
360  friend bool
361  operator==(const scoped_allocator_adaptor<_OutA1, _InA...>& __a,
362  const scoped_allocator_adaptor<_OutA2, _InA...>& __b) noexcept;
363  };
364 
365  template <typename _OutA1, typename _OutA2, typename... _InA>
366  inline bool
367  operator==(const scoped_allocator_adaptor<_OutA1, _InA...>& __a,
368  const scoped_allocator_adaptor<_OutA2, _InA...>& __b) noexcept
369  {
370  return __a.outer_allocator() == __b.outer_allocator()
371  && __a._M_inner == __b._M_inner;
372  }
373 
374  template <typename _OutA1, typename _OutA2, typename... _InA>
375  inline bool
376  operator!=(const scoped_allocator_adaptor<_OutA1, _InA...>& __a,
377  const scoped_allocator_adaptor<_OutA2, _InA...>& __b) noexcept
378  { return !(__a == __b); }
379 
380  /// @}
381 
382 _GLIBCXX_END_NAMESPACE_VERSION
383 } // namespace
384 
385 #endif // __GXX_EXPERIMENTAL_CXX0X__
386 
387 #endif // _SCOPED_ALLOCATOR
std::allocator_traits::deallocate
static void deallocate(_Alloc &__a, pointer __p, size_type __n)
Deallocate memory.
Definition: bits/alloc_traits.h:378
std::allocator_traits::size_type
__size_type size_type
The allocator's size type.
Definition: bits/alloc_traits.h:164
std::allocator_traits::void_pointer
__void_pointer void_pointer
The allocator's void pointer type.
Definition: bits/alloc_traits.h:131
std::forward
constexpr _Tp && forward(typename std::remove_reference< _Tp >::type &__t) noexcept
Forward an lvalue.
Definition: move.h:77
std::allocator_traits::allocate
static pointer allocate(_Alloc &__a, size_type __n)
Allocate memory.
Definition: bits/alloc_traits.h:352
std::allocator_traits::difference_type
__difference_type difference_type
The allocator's difference type.
Definition: bits/alloc_traits.h:153
std::false_type
integral_constant< bool, false > false_type
The type used as a compile-time boolean with false value.
Definition: type_traits:69
std::allocator_traits::max_size
static size_type max_size(const _Alloc &__a)
The maximum supported allocation size.
Definition: bits/alloc_traits.h:417
std::true_type
integral_constant< bool, true > true_type
The type used as a compile-time boolean with true value.
Definition: type_traits:66
std::allocator_traits::const_pointer
__const_pointer const_pointer
The allocator's const pointer type.
Definition: bits/alloc_traits.h:120
std::allocator_traits::pointer
__pointer pointer
The allocator's pointer type.
Definition: bits/alloc_traits.h:109
std::allocator_traits::const_void_pointer
__const_void_pointer const_void_pointer
The allocator's const void pointer type.
Definition: bits/alloc_traits.h:142
std::allocator_traits::destroy
static void destroy(_Alloc &__a, _Tp *__p)
Destroy an object of type _Tp.
Definition: bits/alloc_traits.h:406
std::allocator_traits::value_type
_Alloc::value_type value_type
The allocated type.
Definition: bits/alloc_traits.h:92
std::scoped_allocator_adaptor
Primary class template.
Definition: scoped_allocator:94