1// <scoped_allocator> -*- C++ -*- 2 3// Copyright (C) 2011-2021 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 * @ingroup allocators 28 */ 29 30#ifndef _SCOPED_ALLOCATOR 31#define _SCOPED_ALLOCATOR 1 32 33#pragma GCC system_header 34 35#if __cplusplus < 201103L 36# include <bits/c++0x_warning.h> 37#else 38 39#include <tuple> 40#include <bits/alloc_traits.h> 41#include <bits/stl_pair.h> 42#include <bits/uses_allocator.h> 43#if __cplusplus > 201703L 44# include <bits/uses_allocator_args.h> 45#endif 46 47namespace std _GLIBCXX_VISIBILITY(default) 48{ 49_GLIBCXX_BEGIN_NAMESPACE_VERSION 50 51 /** 52 * @addtogroup allocators 53 * @{ 54 */ 55 56 template<typename _OuterAlloc, typename... _InnerAllocs> 57 class scoped_allocator_adaptor; 58 59 /// @cond undocumented 60 61 template<typename _Alloc> 62 using __outer_allocator_t 63 = decltype(std::declval<_Alloc>().outer_allocator()); 64 65 template<typename _Alloc, typename = void> 66 struct __outermost_type 67 { 68 using type = _Alloc; 69 static type& _S_outermost(_Alloc& __a) { return __a; } 70 }; 71 72 template<typename _Alloc> 73 struct __outermost_type<_Alloc, __void_t<__outer_allocator_t<_Alloc>>> 74 : __outermost_type< 75 typename remove_reference<__outer_allocator_t<_Alloc>>::type 76 > 77 { 78 using __base = __outermost_type< 79 typename remove_reference<__outer_allocator_t<_Alloc>>::type 80 >; 81 82 static typename __base::type& 83 _S_outermost(_Alloc& __a) 84 { return __base::_S_outermost(__a.outer_allocator()); } 85 }; 86 87 // Implementation of the OUTERMOST pseudofunction 88 template<typename _Alloc> 89 inline typename __outermost_type<_Alloc>::type& 90 __outermost(_Alloc& __a) 91 { return __outermost_type<_Alloc>::_S_outermost(__a); } 92 93 template<typename...> 94 struct __inner_type_impl; 95 96 template<typename _Outer> 97 struct __inner_type_impl<_Outer> 98 { 99 typedef scoped_allocator_adaptor<_Outer> __type; 100 101 __inner_type_impl() = default; 102 __inner_type_impl(const __inner_type_impl&) = default; 103 __inner_type_impl(__inner_type_impl&&) = default; 104 __inner_type_impl& operator=(const __inner_type_impl&) = default; 105 __inner_type_impl& operator=(__inner_type_impl&&) = default; 106 107 template<typename _Alloc> 108 __inner_type_impl(const __inner_type_impl<_Alloc>& __other) 109 { } 110 111 template<typename _Alloc> 112 __inner_type_impl(__inner_type_impl<_Alloc>&& __other) 113 { } 114 115 __type& 116 _M_get(__type* __p) noexcept { return *__p; } 117 118 const __type& 119 _M_get(const __type* __p) const noexcept { return *__p; } 120 121 tuple<> 122 _M_tie() const noexcept { return tuple<>(); } 123 124 bool 125 operator==(const __inner_type_impl&) const noexcept 126 { return true; } 127 }; 128 129 template<typename _Outer, typename _InnerHead, typename... _InnerTail> 130 struct __inner_type_impl<_Outer, _InnerHead, _InnerTail...> 131 { 132 typedef scoped_allocator_adaptor<_InnerHead, _InnerTail...> __type; 133 134 __inner_type_impl() = default; 135 __inner_type_impl(const __inner_type_impl&) = default; 136 __inner_type_impl(__inner_type_impl&&) = default; 137 __inner_type_impl& operator=(const __inner_type_impl&) = default; 138 __inner_type_impl& operator=(__inner_type_impl&&) = default; 139 140 template<typename... _Allocs> 141 __inner_type_impl(const __inner_type_impl<_Allocs...>& __other) 142 : _M_inner(__other._M_inner) { } 143 144 template<typename... _Allocs> 145 __inner_type_impl(__inner_type_impl<_Allocs...>&& __other) 146 : _M_inner(std::move(__other._M_inner)) { } 147 148 template<typename... _Args> 149 explicit 150 __inner_type_impl(_Args&&... __args) 151 : _M_inner(std::forward<_Args>(__args)...) { } 152 153 __type& 154 _M_get(void*) noexcept { return _M_inner; } 155 156 const __type& 157 _M_get(const void*) const noexcept { return _M_inner; } 158 159 tuple<const _InnerHead&, const _InnerTail&...> 160 _M_tie() const noexcept 161 { return _M_inner._M_tie(); } 162 163 bool 164 operator==(const __inner_type_impl& __other) const noexcept 165 { return _M_inner == __other._M_inner; } 166 167 private: 168 template<typename...> friend class __inner_type_impl; 169 template<typename, typename...> friend class scoped_allocator_adaptor; 170 171 __type _M_inner; 172 }; 173 174 /// @endcond 175 176 /// An adaptor to recursively pass an allocator to the objects it constructs 177 template<typename _OuterAlloc, typename... _InnerAllocs> 178 class scoped_allocator_adaptor 179 : public _OuterAlloc 180 { 181 typedef allocator_traits<_OuterAlloc> __traits; 182 183 typedef __inner_type_impl<_OuterAlloc, _InnerAllocs...> __inner_type; 184 __inner_type _M_inner; 185 186 template<typename _Outer, typename... _Inner> 187 friend class scoped_allocator_adaptor; 188 189 template<typename...> 190 friend class __inner_type_impl; 191 192 tuple<const _OuterAlloc&, const _InnerAllocs&...> 193 _M_tie() const noexcept 194 { return std::tuple_cat(std::tie(outer_allocator()), _M_inner._M_tie()); } 195 196 template<typename _Alloc> 197 using __outermost_alloc_traits 198 = allocator_traits<typename __outermost_type<_Alloc>::type>; 199 200#if ! __cpp_lib_make_obj_using_allocator 201 template<typename _Tp, typename... _Args> 202 void 203 _M_construct(__uses_alloc0, _Tp* __p, _Args&&... __args) 204 { 205 typedef __outermost_alloc_traits<scoped_allocator_adaptor> _O_traits; 206 _O_traits::construct(__outermost(*this), __p, 207 std::forward<_Args>(__args)...); 208 } 209 210 typedef __uses_alloc1<typename __inner_type::__type> __uses_alloc1_; 211 typedef __uses_alloc2<typename __inner_type::__type> __uses_alloc2_; 212 213 template<typename _Tp, typename... _Args> 214 void 215 _M_construct(__uses_alloc1_, _Tp* __p, _Args&&... __args) 216 { 217 typedef __outermost_alloc_traits<scoped_allocator_adaptor> _O_traits; 218 _O_traits::construct(__outermost(*this), __p, 219 allocator_arg, inner_allocator(), 220 std::forward<_Args>(__args)...); 221 } 222 223 template<typename _Tp, typename... _Args> 224 void 225 _M_construct(__uses_alloc2_, _Tp* __p, _Args&&... __args) 226 { 227 typedef __outermost_alloc_traits<scoped_allocator_adaptor> _O_traits; 228 _O_traits::construct(__outermost(*this), __p, 229 std::forward<_Args>(__args)..., 230 inner_allocator()); 231 } 232#endif // ! make_obj_using_allocator 233 234 template<typename _Alloc> 235 static _Alloc 236 _S_select_on_copy(const _Alloc& __a) 237 { 238 typedef allocator_traits<_Alloc> __a_traits; 239 return __a_traits::select_on_container_copy_construction(__a); 240 } 241 242 template<std::size_t... _Indices> 243 scoped_allocator_adaptor(tuple<const _OuterAlloc&, 244 const _InnerAllocs&...> __refs, 245 _Index_tuple<_Indices...>) 246 : _OuterAlloc(_S_select_on_copy(std::get<0>(__refs))), 247 _M_inner(_S_select_on_copy(std::get<_Indices+1>(__refs))...) 248 { } 249 250 // Used to constrain constructors to disallow invalid conversions. 251 template<typename _Alloc> 252 using _Constructible = typename enable_if< 253 is_constructible<_OuterAlloc, _Alloc>::value 254 >::type; 255 256 // _GLIBCXX_RESOLVE_LIB_DEFECTS 257 // 2975. Missing case for pair construction in scoped [...] allocators 258 template<typename _Tp> 259 struct __not_pair { using type = void; }; 260 261 template<typename _Tp, typename _Up> 262 struct __not_pair<pair<_Tp, _Up>> { }; 263 264 public: 265 typedef _OuterAlloc outer_allocator_type; 266 typedef typename __inner_type::__type inner_allocator_type; 267 268 typedef typename __traits::value_type value_type; 269 typedef typename __traits::size_type size_type; 270 typedef typename __traits::difference_type difference_type; 271 typedef typename __traits::pointer pointer; 272 typedef typename __traits::const_pointer const_pointer; 273 typedef typename __traits::void_pointer void_pointer; 274 typedef typename __traits::const_void_pointer const_void_pointer; 275 276 typedef typename __or_< 277 typename __traits::propagate_on_container_copy_assignment, 278 typename allocator_traits<_InnerAllocs>:: 279 propagate_on_container_copy_assignment...>::type 280 propagate_on_container_copy_assignment; 281 282 typedef typename __or_< 283 typename __traits::propagate_on_container_move_assignment, 284 typename allocator_traits<_InnerAllocs>:: 285 propagate_on_container_move_assignment...>::type 286 propagate_on_container_move_assignment; 287 288 typedef typename __or_< 289 typename __traits::propagate_on_container_swap, 290 typename allocator_traits<_InnerAllocs>:: 291 propagate_on_container_swap...>::type 292 propagate_on_container_swap; 293 294 typedef typename __and_< 295 typename __traits::is_always_equal, 296 typename allocator_traits<_InnerAllocs>::is_always_equal...>::type 297 is_always_equal; 298 299 template <class _Tp> 300 struct rebind 301 { 302 typedef scoped_allocator_adaptor< 303 typename __traits::template rebind_alloc<_Tp>, 304 _InnerAllocs...> other; 305 }; 306 307 scoped_allocator_adaptor() : _OuterAlloc(), _M_inner() { } 308 309 template<typename _Outer2, typename = _Constructible<_Outer2>> 310 scoped_allocator_adaptor(_Outer2&& __outer, 311 const _InnerAllocs&... __inner) 312 : _OuterAlloc(std::forward<_Outer2>(__outer)), 313 _M_inner(__inner...) 314 { } 315 316 scoped_allocator_adaptor(const scoped_allocator_adaptor& __other) 317 : _OuterAlloc(__other.outer_allocator()), 318 _M_inner(__other._M_inner) 319 { } 320 321 scoped_allocator_adaptor(scoped_allocator_adaptor&& __other) 322 : _OuterAlloc(std::move(__other.outer_allocator())), 323 _M_inner(std::move(__other._M_inner)) 324 { } 325 326 template<typename _Outer2, typename = _Constructible<const _Outer2&>> 327 scoped_allocator_adaptor( 328 const scoped_allocator_adaptor<_Outer2, _InnerAllocs...>& __other) 329 : _OuterAlloc(__other.outer_allocator()), 330 _M_inner(__other._M_inner) 331 { } 332 333 template<typename _Outer2, typename = _Constructible<_Outer2>> 334 scoped_allocator_adaptor( 335 scoped_allocator_adaptor<_Outer2, _InnerAllocs...>&& __other) 336 : _OuterAlloc(std::move(__other.outer_allocator())), 337 _M_inner(std::move(__other._M_inner)) 338 { } 339 340 scoped_allocator_adaptor& 341 operator=(const scoped_allocator_adaptor&) = default; 342 343 scoped_allocator_adaptor& 344 operator=(scoped_allocator_adaptor&&) = default; 345 346 inner_allocator_type& inner_allocator() noexcept 347 { return _M_inner._M_get(this); } 348 349 const inner_allocator_type& inner_allocator() const noexcept 350 { return _M_inner._M_get(this); } 351 352 outer_allocator_type& outer_allocator() noexcept 353 { return static_cast<_OuterAlloc&>(*this); } 354 355 const outer_allocator_type& outer_allocator() const noexcept 356 { return static_cast<const _OuterAlloc&>(*this); } 357 358 _GLIBCXX_NODISCARD pointer allocate(size_type __n) 359 { return __traits::allocate(outer_allocator(), __n); } 360 361 _GLIBCXX_NODISCARD pointer allocate(size_type __n, const_void_pointer __hint) 362 { return __traits::allocate(outer_allocator(), __n, __hint); } 363 364 void deallocate(pointer __p, size_type __n) 365 { return __traits::deallocate(outer_allocator(), __p, __n); } 366 367 size_type max_size() const 368 { return __traits::max_size(outer_allocator()); } 369 370#if ! __cpp_lib_make_obj_using_allocator 371 template<typename _Tp, typename... _Args> 372 typename __not_pair<_Tp>::type 373 construct(_Tp* __p, _Args&&... __args) 374 { 375 auto& __inner = inner_allocator(); 376 auto __use_tag 377 = std::__use_alloc<_Tp, inner_allocator_type, _Args...>(__inner); 378 _M_construct(__use_tag, __p, std::forward<_Args>(__args)...); 379 } 380 381 template<typename _T1, typename _T2, typename... _Args1, 382 typename... _Args2> 383 void 384 construct(pair<_T1, _T2>* __p, piecewise_construct_t, 385 tuple<_Args1...> __x, tuple<_Args2...> __y) 386 { 387 // _GLIBCXX_RESOLVE_LIB_DEFECTS 388 // 2203. wrong argument types for piecewise construction 389 auto& __inner = inner_allocator(); 390 auto __x_use_tag 391 = std::__use_alloc<_T1, inner_allocator_type, _Args1...>(__inner); 392 auto __y_use_tag 393 = std::__use_alloc<_T2, inner_allocator_type, _Args2...>(__inner); 394 typename _Build_index_tuple<sizeof...(_Args1)>::__type __x_indices; 395 typename _Build_index_tuple<sizeof...(_Args2)>::__type __y_indices; 396 typedef __outermost_alloc_traits<scoped_allocator_adaptor> _O_traits; 397 _O_traits::construct(__outermost(*this), __p, piecewise_construct, 398 _M_construct_p(__x_use_tag, __x_indices, __x), 399 _M_construct_p(__y_use_tag, __y_indices, __y)); 400 } 401 402 template<typename _T1, typename _T2> 403 void 404 construct(pair<_T1, _T2>* __p) 405 { construct(__p, piecewise_construct, tuple<>(), tuple<>()); } 406 407 template<typename _T1, typename _T2, typename _Up, typename _Vp> 408 void 409 construct(pair<_T1, _T2>* __p, _Up&& __u, _Vp&& __v) 410 { 411 construct(__p, piecewise_construct, 412 std::forward_as_tuple(std::forward<_Up>(__u)), 413 std::forward_as_tuple(std::forward<_Vp>(__v))); 414 } 415 416 template<typename _T1, typename _T2, typename _Up, typename _Vp> 417 void 418 construct(pair<_T1, _T2>* __p, const pair<_Up, _Vp>& __x) 419 { 420 construct(__p, piecewise_construct, 421 std::forward_as_tuple(__x.first), 422 std::forward_as_tuple(__x.second)); 423 } 424 425 template<typename _T1, typename _T2, typename _Up, typename _Vp> 426 void 427 construct(pair<_T1, _T2>* __p, pair<_Up, _Vp>&& __x) 428 { 429 construct(__p, piecewise_construct, 430 std::forward_as_tuple(std::forward<_Up>(__x.first)), 431 std::forward_as_tuple(std::forward<_Vp>(__x.second))); 432 } 433#else // make_obj_using_allocator 434 template<typename _Tp, typename... _Args> 435 __attribute__((__nonnull__)) 436 void 437 construct(_Tp* __p, _Args&&... __args) 438 { 439 typedef __outermost_alloc_traits<scoped_allocator_adaptor> _O_traits; 440 std::apply([__p, this](auto&&... __newargs) { 441 _O_traits::construct(__outermost(*this), __p, 442 std::forward<decltype(__newargs)>(__newargs)...); 443 }, 444 uses_allocator_construction_args<_Tp>(inner_allocator(), 445 std::forward<_Args>(__args)...)); 446 } 447#endif 448 449 template<typename _Tp> 450 void destroy(_Tp* __p) 451 { 452 typedef __outermost_alloc_traits<scoped_allocator_adaptor> _O_traits; 453 _O_traits::destroy(__outermost(*this), __p); 454 } 455 456 scoped_allocator_adaptor 457 select_on_container_copy_construction() const 458 { 459 typedef typename _Build_index_tuple<sizeof...(_InnerAllocs)>::__type 460 _Indices; 461 return scoped_allocator_adaptor(_M_tie(), _Indices()); 462 } 463 464 template <typename _OutA1, typename _OutA2, typename... _InA> 465 friend bool 466 operator==(const scoped_allocator_adaptor<_OutA1, _InA...>& __a, 467 const scoped_allocator_adaptor<_OutA2, _InA...>& __b) noexcept; 468 469 private: 470#if ! __cpp_lib_make_obj_using_allocator 471 template<typename _Ind, typename... _Args> 472 tuple<_Args&&...> 473 _M_construct_p(__uses_alloc0, _Ind, tuple<_Args...>& __t) 474 { return std::move(__t); } 475 476 template<size_t... _Ind, typename... _Args> 477 tuple<allocator_arg_t, inner_allocator_type&, _Args&&...> 478 _M_construct_p(__uses_alloc1_, _Index_tuple<_Ind...>, 479 tuple<_Args...>& __t) 480 { 481 return { allocator_arg, inner_allocator(), 482 std::get<_Ind>(std::move(__t))... 483 }; 484 } 485 486 template<size_t... _Ind, typename... _Args> 487 tuple<_Args&&..., inner_allocator_type&> 488 _M_construct_p(__uses_alloc2_, _Index_tuple<_Ind...>, 489 tuple<_Args...>& __t) 490 { 491 return { std::get<_Ind>(std::move(__t))..., inner_allocator() }; 492 } 493#endif // ! make_obj_using_allocator 494 }; 495 496 /// @related std::scoped_allocator_adaptor 497 template <typename _OutA1, typename _OutA2, typename... _InA> 498 inline bool 499 operator==(const scoped_allocator_adaptor<_OutA1, _InA...>& __a, 500 const scoped_allocator_adaptor<_OutA2, _InA...>& __b) noexcept 501 { 502 return __a.outer_allocator() == __b.outer_allocator() 503 && __a._M_inner == __b._M_inner; 504 } 505 506#if __cpp_impl_three_way_comparison < 201907L 507 /// @related std::scoped_allocator_adaptor 508 template <typename _OutA1, typename _OutA2, typename... _InA> 509 inline bool 510 operator!=(const scoped_allocator_adaptor<_OutA1, _InA...>& __a, 511 const scoped_allocator_adaptor<_OutA2, _InA...>& __b) noexcept 512 { return !(__a == __b); } 513#endif 514 515 /// @} 516 517_GLIBCXX_END_NAMESPACE_VERSION 518} // namespace 519 520#endif // C++11 521 522#endif // _SCOPED_ALLOCATOR 523