scoped_allocator source code [include/c++/7/scoped

1	// <scoped_allocator> -- C++ --
2
3	// Copyright (C) 2011-2017 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 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	#if __cplusplus < 201103L
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	/**
47	* @addtogroup allocators
48	* @{
49	*/
50
51	template<typename _Alloc>
52	using __outer_allocator_t
53	= decltype(std::declval<_Alloc>().outer_allocator());
54
55	template<typename _Alloc, typename = void>
56	struct __outermost_type
57	{
58	using type = _Alloc;
59	static type& _S_outermost(_Alloc& __a) { return __a; }
60	};
61
62	template<typename _Alloc>
63	struct __outermost_type<_Alloc, __void_t<__outer_allocator_t<_Alloc>>>
64	: __outermost_type<
65	typename remove_reference<__outer_allocator_t<_Alloc>>::type
66	>
67	{
68	using __base = __outermost_type<
69	typename remove_reference<__outer_allocator_t<_Alloc>>::type
70	>;
71
72	static typename __base::type&
73	_S_outermost(_Alloc& __a)
74	{ return __base::_S_outermost(__a.outer_allocator()); }
75	};
76
77	template<typename _Alloc>
78	inline typename __outermost_type<_Alloc>::type&
79	__outermost(_Alloc& __a)
80	{ return __outermost_type<_Alloc>::_S_outermost(__a); }
81
82	template<typename _OuterAlloc, typename... _InnerAllocs>
83	class scoped_allocator_adaptor;
84
85	template<typename...>
86	struct __inner_type_impl;
87
88	template<typename _Outer>
89	struct __inner_type_impl<_Outer>
90	{
91	typedef scoped_allocator_adaptor<_Outer> __type;
92
93	__inner_type_impl() = default;
94	__inner_type_impl(const __inner_type_impl&) = default;
95	__inner_type_impl(__inner_type_impl&&) = default;
96	__inner_type_impl& operator=(const __inner_type_impl&) = default;
97	__inner_type_impl& operator=(__inner_type_impl&&) = default;
98
99	template<typename _Alloc>
100	__inner_type_impl(const __inner_type_impl<_Alloc>& __other)
101	{ }
102
103	template<typename _Alloc>
104	__inner_type_impl(__inner_type_impl<_Alloc>&& __other)
105	{ }
106
107	__type&
108	_M_get(__type* __p) noexcept { return *__p; }
109
110	const __type&
111	_M_get(const __type* __p) const noexcept { return *__p; }
112
113	tuple<>
114	_M_tie() const noexcept { return tuple<>(); }
115
116	bool
117	operator==(const __inner_type_impl&) const noexcept
118	{ return true; }
119	};
120
121	template<typename _Outer, typename _InnerHead, typename... _InnerTail>
122	struct __inner_type_impl<_Outer, _InnerHead, _InnerTail...>
123	{
124	typedef scoped_allocator_adaptor<_InnerHead, _InnerTail...> __type;
125
126	__inner_type_impl() = default;
127	__inner_type_impl(const __inner_type_impl&) = default;
128	__inner_type_impl(__inner_type_impl&&) = default;
129	__inner_type_impl& operator=(const __inner_type_impl&) = default;
130	__inner_type_impl& operator=(__inner_type_impl&&) = default;
131
132	template<typename... _Allocs>
133	__inner_type_impl(const __inner_type_impl<_Allocs...>& __other)
134	: _M_inner(__other._M_inner) { }
135
136	template<typename... _Allocs>
137	__inner_type_impl(__inner_type_impl<_Allocs...>&& __other)
138	: _M_inner(std::move(__other._M_inner)) { }
139
140	template<typename... _Args>
141	explicit
142	__inner_type_impl(_Args&&... __args)
143	: _M_inner(std::forward<_Args>(__args)...) { }
144
145	__type&
146	_M_get(void*) noexcept { return _M_inner; }
147
148	const __type&
149	_M_get(const void*) const noexcept { return _M_inner; }
150
151	tuple<const _InnerHead&, const _InnerTail&...>
152	_M_tie() const noexcept
153	{ return _M_inner._M_tie(); }
154
155	bool
156	operator==(const __inner_type_impl& __other) const noexcept
157	{ return _M_inner == __other._M_inner; }
158
159	private:
160	template<typename...> friend class __inner_type_impl;
161	template<typename, typename...> friend class scoped_allocator_adaptor;
162
163	__type _M_inner;
164	};
165
166	/// Primary class template.
167	template<typename _OuterAlloc, typename... _InnerAllocs>
168	class scoped_allocator_adaptor
169	: public _OuterAlloc
170	{
171	typedef allocator_traits<_OuterAlloc> __traits;
172
173	typedef __inner_type_impl<_OuterAlloc, _InnerAllocs...> __inner_type;
174	__inner_type _M_inner;
175
176	template<typename _Outer, typename... _Inner>
177	friend class scoped_allocator_adaptor;
178
179	template<typename...>
180	friend class __inner_type_impl;
181
182	tuple<const _OuterAlloc&, const _InnerAllocs&...>
183	_M_tie() const noexcept
184	{ return std::tuple_cat(std::tie(outer_allocator()), _M_inner._M_tie()); }
185
186	template<typename _Alloc>
187	using __outermost_alloc_traits
188	= allocator_traits<typename __outermost_type<_Alloc>::type>;
189
190	template<typename _Tp, typename... _Args>
191	void
192	_M_construct(__uses_alloc0, _Tp* __p, _Args&&... __args)
193	{
194	typedef __outermost_alloc_traits<scoped_allocator_adaptor> _O_traits;
195	_O_traits::construct(__outermost(*this), __p,
196	std::forward<_Args>(__args)...);
197	}
198
199	typedef __uses_alloc1<typename __inner_type::__type> __uses_alloc1_;
200	typedef __uses_alloc2<typename __inner_type::__type> __uses_alloc2_;
201
202	template<typename _Tp, typename... _Args>
203	void
204	_M_construct(__uses_alloc1_, _Tp* __p, _Args&&... __args)
205	{
206	typedef __outermost_alloc_traits<scoped_allocator_adaptor> _O_traits;
207	_O_traits::construct(__outermost(*this), __p,
208	allocator_arg, inner_allocator(),
209	std::forward<_Args>(__args)...);
210	}
211
212	template<typename _Tp, typename... _Args>
213	void
214	_M_construct(__uses_alloc2_, _Tp* __p, _Args&&... __args)
215	{
216	typedef __outermost_alloc_traits<scoped_allocator_adaptor> _O_traits;
217	_O_traits::construct(__outermost(*this), __p,
218	std::forward<_Args>(__args)...,
219	inner_allocator());
220	}
221
222	template<typename _Alloc>
223	static _Alloc
224	_S_select_on_copy(const _Alloc& __a)
225	{
226	typedef allocator_traits<_Alloc> __a_traits;
227	return __a_traits::select_on_container_copy_construction(__a);
228	}
229
230	template<std::size_t... _Indices>
231	scoped_allocator_adaptor(tuple<const _OuterAlloc&,
232	const _InnerAllocs&...> __refs,
233	_Index_tuple<_Indices...>)
234	: _OuterAlloc(_S_select_on_copy(std::get<0>(__refs))),
235	_M_inner(_S_select_on_copy(std::get<_Indices+1>(__refs))...)
236	{ }
237
238	// Used to constrain constructors to disallow invalid conversions.
239	template<typename _Alloc>
240	using _Constructible = typename enable_if<
241	is_constructible<_OuterAlloc, _Alloc>::value
242	>::type;
243
244	public:
245	typedef _OuterAlloc outer_allocator_type;
246	typedef typename __inner_type::__type inner_allocator_type;
247
248	typedef typename __traits::value_type value_type;
249	typedef typename __traits::size_type size_type;
250	typedef typename __traits::difference_type difference_type;
251	typedef typename __traits::pointer pointer;
252	typedef typename __traits::const_pointer const_pointer;
253	typedef typename __traits::void_pointer void_pointer;
254	typedef typename __traits::const_void_pointer const_void_pointer;
255
256	typedef typename __or_<
257	typename __traits::propagate_on_container_copy_assignment,
258	typename allocator_traits<_InnerAllocs>::
259	propagate_on_container_copy_assignment...>::type
260	propagate_on_container_copy_assignment;
261
262	typedef typename __or_<
263	typename __traits::propagate_on_container_move_assignment,
264	typename allocator_traits<_InnerAllocs>::
265	propagate_on_container_move_assignment...>::type
266	propagate_on_container_move_assignment;
267
268	typedef typename __or_<
269	typename __traits::propagate_on_container_swap,
270	typename allocator_traits<_InnerAllocs>::
271	propagate_on_container_swap...>::type
272	propagate_on_container_swap;
273
274	typedef typename __and_<
275	typename __traits::is_always_equal,
276	typename allocator_traits<_InnerAllocs>::is_always_equal...>::type
277	is_always_equal;
278
279	template <class _Tp>
280	struct rebind
281	{
282	typedef scoped_allocator_adaptor<
283	typename __traits::template rebind_alloc<_Tp>,
284	_InnerAllocs...> other;
285	};
286
287	scoped_allocator_adaptor() : _OuterAlloc(), _M_inner() { }
288
289	template<typename _Outer2, typename = _Constructible<_Outer2>>
290	scoped_allocator_adaptor(_Outer2&& __outer,
291	const _InnerAllocs&... __inner)
292	: _OuterAlloc(std::forward<_Outer2>(__outer)),
293	_M_inner(__inner...)
294	{ }
295
296	scoped_allocator_adaptor(const scoped_allocator_adaptor& __other)
297	: _OuterAlloc(__other.outer_allocator()),
298	_M_inner(__other._M_inner)
299	{ }
300
301	scoped_allocator_adaptor(scoped_allocator_adaptor&& __other)
302	: _OuterAlloc(std::move(__other.outer_allocator())),
303	_M_inner(std::move(__other._M_inner))
304	{ }
305
306	template<typename _Outer2, typename = _Constructible<const _Outer2&>>
307	scoped_allocator_adaptor(
308	const scoped_allocator_adaptor<_Outer2, _InnerAllocs...>& __other)
309	: _OuterAlloc(__other.outer_allocator()),
310	_M_inner(__other._M_inner)
311	{ }
312
313	template<typename _Outer2, typename = _Constructible<_Outer2>>
314	scoped_allocator_adaptor(
315	scoped_allocator_adaptor<_Outer2, _InnerAllocs...>&& __other)
316	: _OuterAlloc(std::move(__other.outer_allocator())),
317	_M_inner(std::move(__other._M_inner))
318	{ }
319
320	scoped_allocator_adaptor&
321	operator=(const scoped_allocator_adaptor&) = default;
322
323	scoped_allocator_adaptor&
324	operator=(scoped_allocator_adaptor&&) = default;
325
326	inner_allocator_type& inner_allocator() noexcept
327	{ return _M_inner._M_get(this); }
328
329	const inner_allocator_type& inner_allocator() const noexcept
330	{ return _M_inner._M_get(this); }
331
332	outer_allocator_type& outer_allocator() noexcept
333	{ return static_cast<_OuterAlloc&>(*this); }
334
335	const outer_allocator_type& outer_allocator() const noexcept
336	{ return static_cast<const _OuterAlloc&>(*this); }
337
338	pointer allocate(size_type __n)
339	{ return __traits::allocate(outer_allocator(), __n); }
340
341	pointer allocate(size_type __n, const_void_pointer __hint)
342	{ return __traits::allocate(outer_allocator(), __n, __hint); }
343
344	void deallocate(pointer __p, size_type __n)
345	{ return __traits::deallocate(outer_allocator(), __p, __n); }
346
347	size_type max_size() const
348	{ return __traits::max_size(outer_allocator()); }
349
350	template<typename _Tp, typename... _Args>
351	void construct(_Tp* __p, _Args&&... __args)
352	{
353	auto& __inner = inner_allocator();
354	auto __use_tag
355	= __use_alloc<_Tp, inner_allocator_type, _Args...>(__inner);
356	_M_construct(__use_tag, __p, std::forward<_Args>(__args)...);
357	}
358
359	template<typename _T1, typename _T2, typename... _Args1,
360	typename... _Args2>
361	void
362	construct(pair<_T1, _T2>* __p, piecewise_construct_t,
363	tuple<_Args1...> __x, tuple<_Args2...> __y)
364	{
365	// _GLIBCXX_RESOLVE_LIB_DEFECTS
366	// 2203. wrong argument types for piecewise construction
367	auto& __inner = inner_allocator();
368	auto __x_use_tag
369	= __use_alloc<_T1, inner_allocator_type, _Args1...>(__inner);
370	auto __y_use_tag
371	= __use_alloc<_T2, inner_allocator_type, _Args2...>(__inner);
372	typename _Build_index_tuple<sizeof...(_Args1)>::__type __x_indices;
373	typename _Build_index_tuple<sizeof...(_Args2)>::__type __y_indices;
374	typedef __outermost_alloc_traits<scoped_allocator_adaptor> _O_traits;
375	_O_traits::construct(__outermost(*this), __p, piecewise_construct,
376	_M_construct_p(__x_use_tag, __x_indices, __x),
377	_M_construct_p(__y_use_tag, __y_indices, __y));
378	}
379
380	template<typename _T1, typename _T2>
381	void
382	construct(pair<_T1, _T2>* __p)
383	{ construct(__p, piecewise_construct, tuple<>(), tuple<>()); }
384
385	template<typename _T1, typename _T2, typename _Up, typename _Vp>
386	void
387	construct(pair<_T1, _T2>* __p, _Up&& __u, _Vp&& __v)
388	{
389	construct(__p, piecewise_construct,
390	std::forward_as_tuple(std::forward<_Up>(__u)),
391	std::forward_as_tuple(std::forward<_Vp>(__v)));
392	}
393
394	template<typename _T1, typename _T2, typename _Up, typename _Vp>
395	void
396	construct(pair<_T1, _T2>* __p, const pair<_Up, _Vp>& __x)
397	{
398	construct(__p, piecewise_construct,
399	std::forward_as_tuple(__x.first),
400	std::forward_as_tuple(__x.second));
401	}
402
403	template<typename _T1, typename _T2, typename _Up, typename _Vp>
404	void
405	construct(pair<_T1, _T2>* __p, pair<_Up, _Vp>&& __x)
406	{
407	construct(__p, piecewise_construct,
408	std::forward_as_tuple(std::forward<_Up>(__x.first)),
409	std::forward_as_tuple(std::forward<_Vp>(__x.second)));
410	}
411
412	template<typename _Tp>
413	void destroy(_Tp* __p)
414	{
415	typedef __outermost_alloc_traits<scoped_allocator_adaptor> _O_traits;
416	_O_traits::destroy(__outermost(*this), __p);
417	}
418
419	scoped_allocator_adaptor
420	select_on_container_copy_construction() const
421	{
422	typedef typename _Build_index_tuple<sizeof...(_InnerAllocs)>::__type
423	_Indices;
424	return scoped_allocator_adaptor(_M_tie(), _Indices());
425	}
426
427	template <typename _OutA1, typename _OutA2, typename... _InA>
428	friend bool
429	operator==(const scoped_allocator_adaptor<_OutA1, _InA...>& __a,
430	const scoped_allocator_adaptor<_OutA2, _InA...>& __b) noexcept;
431
432	private:
433	template<typename _Ind, typename... _Args>
434	tuple<_Args&&...>
435	_M_construct_p(__uses_alloc0, _Ind, tuple<_Args...>& __t)
436	{ return std::move(__t); }
437
438	template<size_t... _Ind, typename... _Args>
439	tuple<allocator_arg_t, inner_allocator_type&, _Args&&...>
440	_M_construct_p(__uses_alloc1_, _Index_tuple<_Ind...>,
441	tuple<_Args...>& __t)
442	{
443	return { allocator_arg, inner_allocator(),
444	std::get<_Ind>(std::move(__t))...
445	};
446	}
447
448	template<size_t... _Ind, typename... _Args>
449	tuple<_Args&&..., inner_allocator_type&>
450	_M_construct_p(__uses_alloc2_, _Index_tuple<_Ind...>,
451	tuple<_Args...>& __t)
452	{
453	return { std::get<_Ind>(std::move(__t))..., inner_allocator() };
454	}
455	};
456
457	template <typename _OutA1, typename _OutA2, typename... _InA>
458	inline bool
459	operator==(const scoped_allocator_adaptor<_OutA1, _InA...>& __a,
460	const scoped_allocator_adaptor<_OutA2, _InA...>& __b) noexcept
461	{
462	return __a.outer_allocator() == __b.outer_allocator()
463	&& __a._M_inner == __b._M_inner;
464	}
465
466	template <typename _OutA1, typename _OutA2, typename... _InA>
467	inline bool
468	operator!=(const scoped_allocator_adaptor<_OutA1, _InA...>& __a,
469	const scoped_allocator_adaptor<_OutA2, _InA...>& __b) noexcept
470	{ return !(__a == __b); }
471
472	/// @}
473
474	_GLIBCXX_END_NAMESPACE_VERSION
475	} // namespace
476
477	#endif // C++11
478
479	#endif // _SCOPED_ALLOCATOR
480