1// <scoped_allocator> -*- C++ -*-
3// Copyright (C) 2011-2024 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 include/scoped_allocator
26 * This is a Standard C++ Library header.
29#ifndef _SCOPED_ALLOCATOR
30#define _SCOPED_ALLOCATOR 1
32#pragma GCC system_header
34#if __cplusplus < 201103L
35# include <bits/c++0x_warning.h>
39#include <bits/alloc_traits.h>
40#include <bits/stl_pair.h>
41#include <bits/uses_allocator.h>
42#if __cplusplus > 201703L
43# include <bits/uses_allocator_args.h>
46#define __glibcxx_want_allocator_traits_is_always_equal
47#include <bits/version.h>
49namespace std _GLIBCXX_VISIBILITY(default)
51_GLIBCXX_BEGIN_NAMESPACE_VERSION
54 * @addtogroup allocators
58 template<typename _OuterAlloc, typename... _InnerAllocs>
59 class scoped_allocator_adaptor;
61 /// @cond undocumented
63 template<typename _Alloc>
64 using __outer_allocator_t
65 = decltype(std::declval<_Alloc>().outer_allocator());
67 template<typename _Alloc, typename = void>
68 struct __outermost_type
71 static type& _S_outermost(_Alloc& __a) noexcept { return __a; }
74 template<typename _Alloc>
75 struct __outermost_type<_Alloc, __void_t<__outer_allocator_t<_Alloc>>>
77 typename remove_reference<__outer_allocator_t<_Alloc>>::type
80 using __base = __outermost_type<
81 typename remove_reference<__outer_allocator_t<_Alloc>>::type
84 static typename __base::type&
85 _S_outermost(_Alloc& __a) noexcept
86 { return __base::_S_outermost(__a.outer_allocator()); }
89 // Implementation of the OUTERMOST pseudofunction
90 template<typename _Alloc>
91 inline typename __outermost_type<_Alloc>::type&
92 __outermost(_Alloc& __a)
93 { return __outermost_type<_Alloc>::_S_outermost(__a); }
96 struct __inner_type_impl;
98 template<typename _Outer>
99 struct __inner_type_impl<_Outer>
101 typedef scoped_allocator_adaptor<_Outer> __type;
103 __inner_type_impl() = default;
104 __inner_type_impl(const __inner_type_impl&) = default;
105 __inner_type_impl(__inner_type_impl&&) = default;
106 __inner_type_impl& operator=(const __inner_type_impl&) = default;
107 __inner_type_impl& operator=(__inner_type_impl&&) = default;
109 template<typename _Alloc>
110 __inner_type_impl(const __inner_type_impl<_Alloc>&) noexcept
113 template<typename _Alloc>
114 __inner_type_impl(__inner_type_impl<_Alloc>&&) noexcept
118 _M_get(__type* __p) noexcept { return *__p; }
121 _M_get(const __type* __p) const noexcept { return *__p; }
124 _M_tie() const noexcept { return tuple<>(); }
127 operator==(const __inner_type_impl&) const noexcept
131 template<typename _Outer, typename _InnerHead, typename... _InnerTail>
132 struct __inner_type_impl<_Outer, _InnerHead, _InnerTail...>
134 typedef scoped_allocator_adaptor<_InnerHead, _InnerTail...> __type;
136 __inner_type_impl() = default;
137 __inner_type_impl(const __inner_type_impl&) = default;
138 __inner_type_impl(__inner_type_impl&&) = default;
139 __inner_type_impl& operator=(const __inner_type_impl&) = default;
140 __inner_type_impl& operator=(__inner_type_impl&&) = default;
142 template<typename... _Allocs>
143 __inner_type_impl(const __inner_type_impl<_Allocs...>& __other) noexcept
144 : _M_inner(__other._M_inner) { }
146 template<typename... _Allocs>
147 __inner_type_impl(__inner_type_impl<_Allocs...>&& __other) noexcept
148 : _M_inner(std::move(__other._M_inner)) { }
150 template<typename... _Args>
152 __inner_type_impl(_Args&&... __args) noexcept
153 : _M_inner(std::forward<_Args>(__args)...) { }
156 _M_get(void*) noexcept { return _M_inner; }
159 _M_get(const void*) const noexcept { return _M_inner; }
161 tuple<const _InnerHead&, const _InnerTail&...>
162 _M_tie() const noexcept
163 { return _M_inner._M_tie(); }
166 operator==(const __inner_type_impl& __other) const noexcept
167 { return _M_inner == __other._M_inner; }
170 template<typename...> friend struct __inner_type_impl;
171 template<typename, typename...> friend class scoped_allocator_adaptor;
178 /// An adaptor to recursively pass an allocator to the objects it constructs
179 template<typename _OuterAlloc, typename... _InnerAllocs>
180 class scoped_allocator_adaptor
183 typedef allocator_traits<_OuterAlloc> __traits;
185 typedef __inner_type_impl<_OuterAlloc, _InnerAllocs...> __inner_type;
186 __inner_type _M_inner;
188 template<typename _Outer, typename... _Inner>
189 friend class scoped_allocator_adaptor;
191 template<typename...>
192 friend struct __inner_type_impl;
194 tuple<const _OuterAlloc&, const _InnerAllocs&...>
195 _M_tie() const noexcept
196 { return std::tuple_cat(std::tie(outer_allocator()), _M_inner._M_tie()); }
198 template<typename _Alloc>
199 using __outermost_alloc_traits
200 = allocator_traits<typename __outermost_type<_Alloc>::type>;
202#if ! __glibcxx_make_obj_using_allocator
203 template<typename _Tp, typename... _Args>
205 _M_construct(__uses_alloc0, _Tp* __p, _Args&&... __args)
207 typedef __outermost_alloc_traits<scoped_allocator_adaptor> _O_traits;
208 _O_traits::construct(__outermost(*this), __p,
209 std::forward<_Args>(__args)...);
212 typedef __uses_alloc1<typename __inner_type::__type> __uses_alloc1_;
213 typedef __uses_alloc2<typename __inner_type::__type> __uses_alloc2_;
215 template<typename _Tp, typename... _Args>
217 _M_construct(__uses_alloc1_, _Tp* __p, _Args&&... __args)
219 typedef __outermost_alloc_traits<scoped_allocator_adaptor> _O_traits;
220 _O_traits::construct(__outermost(*this), __p,
221 allocator_arg, inner_allocator(),
222 std::forward<_Args>(__args)...);
225 template<typename _Tp, typename... _Args>
227 _M_construct(__uses_alloc2_, _Tp* __p, _Args&&... __args)
229 typedef __outermost_alloc_traits<scoped_allocator_adaptor> _O_traits;
230 _O_traits::construct(__outermost(*this), __p,
231 std::forward<_Args>(__args)...,
234#endif // ! make_obj_using_allocator
236 template<typename _Alloc>
238 _S_select_on_copy(const _Alloc& __a)
240 typedef allocator_traits<_Alloc> __a_traits;
241 return __a_traits::select_on_container_copy_construction(__a);
244 template<std::size_t... _Indices>
245 scoped_allocator_adaptor(tuple<const _OuterAlloc&,
246 const _InnerAllocs&...> __refs,
247 _Index_tuple<_Indices...>)
248 : _OuterAlloc(_S_select_on_copy(std::get<0>(__refs))),
249 _M_inner(_S_select_on_copy(std::get<_Indices+1>(__refs))...)
252 // Used to constrain constructors to disallow invalid conversions.
253 template<typename _Alloc>
254 using _Constructible = typename enable_if<
255 is_constructible<_OuterAlloc, _Alloc>::value
258 // _GLIBCXX_RESOLVE_LIB_DEFECTS
259 // 2975. Missing case for pair construction in scoped [...] allocators
260 template<typename _Tp>
261 struct __not_pair { using type = void; };
263 template<typename _Tp, typename _Up>
264 struct __not_pair<pair<_Tp, _Up>> { };
267 typedef _OuterAlloc outer_allocator_type;
268 typedef typename __inner_type::__type inner_allocator_type;
270 typedef typename __traits::value_type value_type;
271 typedef typename __traits::size_type size_type;
272 typedef typename __traits::difference_type difference_type;
273 typedef typename __traits::pointer pointer;
274 typedef typename __traits::const_pointer const_pointer;
275 typedef typename __traits::void_pointer void_pointer;
276 typedef typename __traits::const_void_pointer const_void_pointer;
278 typedef typename __or_<
279 typename __traits::propagate_on_container_copy_assignment,
280 typename allocator_traits<_InnerAllocs>::
281 propagate_on_container_copy_assignment...>::type
282 propagate_on_container_copy_assignment;
284 typedef typename __or_<
285 typename __traits::propagate_on_container_move_assignment,
286 typename allocator_traits<_InnerAllocs>::
287 propagate_on_container_move_assignment...>::type
288 propagate_on_container_move_assignment;
290 typedef typename __or_<
291 typename __traits::propagate_on_container_swap,
292 typename allocator_traits<_InnerAllocs>::
293 propagate_on_container_swap...>::type
294 propagate_on_container_swap;
296 typedef typename __and_<
297 typename __traits::is_always_equal,
298 typename allocator_traits<_InnerAllocs>::is_always_equal...>::type
304 typedef scoped_allocator_adaptor<
305 typename __traits::template rebind_alloc<_Tp>,
306 _InnerAllocs...> other;
309 scoped_allocator_adaptor() : _OuterAlloc(), _M_inner() { }
311 template<typename _Outer2, typename = _Constructible<_Outer2>>
312 scoped_allocator_adaptor(_Outer2&& __outer,
313 const _InnerAllocs&... __inner) noexcept
314 : _OuterAlloc(std::forward<_Outer2>(__outer)),
318 scoped_allocator_adaptor(const scoped_allocator_adaptor& __other) noexcept
319 : _OuterAlloc(__other.outer_allocator()),
320 _M_inner(__other._M_inner)
323 scoped_allocator_adaptor(scoped_allocator_adaptor&& __other) noexcept
324 : _OuterAlloc(std::move(__other.outer_allocator())),
325 _M_inner(std::move(__other._M_inner))
328 template<typename _Outer2, typename = _Constructible<const _Outer2&>>
329 scoped_allocator_adaptor(
330 const scoped_allocator_adaptor<_Outer2, _InnerAllocs...>& __other
332 : _OuterAlloc(__other.outer_allocator()),
333 _M_inner(__other._M_inner)
336 template<typename _Outer2, typename = _Constructible<_Outer2>>
337 scoped_allocator_adaptor(
338 scoped_allocator_adaptor<_Outer2, _InnerAllocs...>&& __other) noexcept
339 : _OuterAlloc(std::move(__other.outer_allocator())),
340 _M_inner(std::move(__other._M_inner))
343 scoped_allocator_adaptor&
344 operator=(const scoped_allocator_adaptor&) = default;
346 scoped_allocator_adaptor&
347 operator=(scoped_allocator_adaptor&&) = default;
349 inner_allocator_type&
350 inner_allocator() noexcept
351 { return _M_inner._M_get(this); }
353 const inner_allocator_type&
354 inner_allocator() const noexcept
355 { return _M_inner._M_get(this); }
357 outer_allocator_type&
358 outer_allocator() noexcept
359 { return static_cast<_OuterAlloc&>(*this); }
361 const outer_allocator_type&
362 outer_allocator() const noexcept
363 { return static_cast<const _OuterAlloc&>(*this); }
365 _GLIBCXX_NODISCARD pointer
366 allocate(size_type __n)
367 { return __traits::allocate(outer_allocator(), __n); }
369 _GLIBCXX_NODISCARD pointer
370 allocate(size_type __n, const_void_pointer __hint)
371 { return __traits::allocate(outer_allocator(), __n, __hint); }
373 void deallocate(pointer __p, size_type __n) noexcept
374 { return __traits::deallocate(outer_allocator(), __p, __n); }
376 size_type max_size() const
377 { return __traits::max_size(outer_allocator()); }
379#if ! __glibcxx_make_obj_using_allocator
380 template<typename _Tp, typename... _Args>
381 typename __not_pair<_Tp>::type
382 construct(_Tp* __p, _Args&&... __args)
384 auto& __inner = inner_allocator();
386 = std::__use_alloc<_Tp, inner_allocator_type, _Args...>(__inner);
387 _M_construct(__use_tag, __p, std::forward<_Args>(__args)...);
390 template<typename _T1, typename _T2, typename... _Args1,
393 construct(pair<_T1, _T2>* __p, piecewise_construct_t,
394 tuple<_Args1...> __x, tuple<_Args2...> __y)
396 // _GLIBCXX_RESOLVE_LIB_DEFECTS
397 // 2203. wrong argument types for piecewise construction
398 auto& __inner = inner_allocator();
400 = std::__use_alloc<_T1, inner_allocator_type, _Args1...>(__inner);
402 = std::__use_alloc<_T2, inner_allocator_type, _Args2...>(__inner);
403 typename _Build_index_tuple<sizeof...(_Args1)>::__type __x_indices;
404 typename _Build_index_tuple<sizeof...(_Args2)>::__type __y_indices;
405 typedef __outermost_alloc_traits<scoped_allocator_adaptor> _O_traits;
406 _O_traits::construct(__outermost(*this), __p, piecewise_construct,
407 _M_construct_p(__x_use_tag, __x_indices, __x),
408 _M_construct_p(__y_use_tag, __y_indices, __y));
411 template<typename _T1, typename _T2>
413 construct(pair<_T1, _T2>* __p)
414 { construct(__p, piecewise_construct, tuple<>(), tuple<>()); }
416 template<typename _T1, typename _T2, typename _Up, typename _Vp>
418 construct(pair<_T1, _T2>* __p, _Up&& __u, _Vp&& __v)
420 construct(__p, piecewise_construct,
421 std::forward_as_tuple(std::forward<_Up>(__u)),
422 std::forward_as_tuple(std::forward<_Vp>(__v)));
425 template<typename _T1, typename _T2, typename _Up, typename _Vp>
427 construct(pair<_T1, _T2>* __p, const pair<_Up, _Vp>& __x)
429 construct(__p, piecewise_construct,
430 std::forward_as_tuple(__x.first),
431 std::forward_as_tuple(__x.second));
434 template<typename _T1, typename _T2, typename _Up, typename _Vp>
436 construct(pair<_T1, _T2>* __p, pair<_Up, _Vp>&& __x)
438 construct(__p, piecewise_construct,
439 std::forward_as_tuple(std::forward<_Up>(__x.first)),
440 std::forward_as_tuple(std::forward<_Vp>(__x.second)));
442#else // make_obj_using_allocator
443 template<typename _Tp, typename... _Args>
444 __attribute__((__nonnull__))
446 construct(_Tp* __p, _Args&&... __args)
448 typedef __outermost_alloc_traits<scoped_allocator_adaptor> _O_traits;
449 std::apply([__p, this](auto&&... __newargs) {
450 _O_traits::construct(__outermost(*this), __p,
451 std::forward<decltype(__newargs)>(__newargs)...);
453 uses_allocator_construction_args<_Tp>(inner_allocator(),
454 std::forward<_Args>(__args)...));
458 template<typename _Tp>
459 void destroy(_Tp* __p)
461 typedef __outermost_alloc_traits<scoped_allocator_adaptor> _O_traits;
462 _O_traits::destroy(__outermost(*this), __p);
465 scoped_allocator_adaptor
466 select_on_container_copy_construction() const
468 typedef typename _Build_index_tuple<sizeof...(_InnerAllocs)>::__type
470 return scoped_allocator_adaptor(_M_tie(), _Indices());
473 template <typename _OutA1, typename _OutA2, typename... _InA>
475 operator==(const scoped_allocator_adaptor<_OutA1, _InA...>& __a,
476 const scoped_allocator_adaptor<_OutA2, _InA...>& __b) noexcept;
479#if ! __glibcxx_make_obj_using_allocator
480 template<typename _Ind, typename... _Args>
482 _M_construct_p(__uses_alloc0, _Ind, tuple<_Args...>& __t)
483 { return std::move(__t); }
485 template<size_t... _Ind, typename... _Args>
486 tuple<allocator_arg_t, inner_allocator_type&, _Args&&...>
487 _M_construct_p(__uses_alloc1_, _Index_tuple<_Ind...>,
488 tuple<_Args...>& __t)
490 return { allocator_arg, inner_allocator(),
491 std::get<_Ind>(std::move(__t))...
495 template<size_t... _Ind, typename... _Args>
496 tuple<_Args&&..., inner_allocator_type&>
497 _M_construct_p(__uses_alloc2_, _Index_tuple<_Ind...>,
498 tuple<_Args...>& __t)
500 return { std::get<_Ind>(std::move(__t))..., inner_allocator() };
502#endif // ! make_obj_using_allocator
505 /// @related std::scoped_allocator_adaptor
506 template <typename _OutA1, typename _OutA2, typename... _InA>
508 operator==(const scoped_allocator_adaptor<_OutA1, _InA...>& __a,
509 const scoped_allocator_adaptor<_OutA2, _InA...>& __b) noexcept
511 return __a.outer_allocator() == __b.outer_allocator()
512 && __a._M_inner == __b._M_inner;
515#if __cpp_impl_three_way_comparison < 201907L
516 /// @related std::scoped_allocator_adaptor
517 template <typename _OutA1, typename _OutA2, typename... _InA>
519 operator!=(const scoped_allocator_adaptor<_OutA1, _InA...>& __a,
520 const scoped_allocator_adaptor<_OutA2, _InA...>& __b) noexcept
521 { return !(__a == __b); }
526_GLIBCXX_END_NAMESPACE_VERSION
531#endif // _SCOPED_ALLOCATOR