1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef _LIBCPP___MEMORY_SHARED_PTR_H 11 #define _LIBCPP___MEMORY_SHARED_PTR_H 12 13 #include <__compare/compare_three_way.h> 14 #include <__compare/ordering.h> 15 #include <__config> 16 #include <__exception/exception.h> 17 #include <__functional/binary_function.h> 18 #include <__functional/operations.h> 19 #include <__functional/reference_wrapper.h> 20 #include <__fwd/ostream.h> 21 #include <__iterator/access.h> 22 #include <__memory/addressof.h> 23 #include <__memory/allocation_guard.h> 24 #include <__memory/allocator.h> 25 #include <__memory/allocator_destructor.h> 26 #include <__memory/allocator_traits.h> 27 #include <__memory/auto_ptr.h> 28 #include <__memory/compressed_pair.h> 29 #include <__memory/construct_at.h> 30 #include <__memory/pointer_traits.h> 31 #include <__memory/uninitialized_algorithms.h> 32 #include <__memory/unique_ptr.h> 33 #include <__type_traits/add_lvalue_reference.h> 34 #include <__type_traits/conditional.h> 35 #include <__type_traits/conjunction.h> 36 #include <__type_traits/disjunction.h> 37 #include <__type_traits/is_array.h> 38 #include <__type_traits/is_bounded_array.h> 39 #include <__type_traits/is_constructible.h> 40 #include <__type_traits/is_convertible.h> 41 #include <__type_traits/is_reference.h> 42 #include <__type_traits/is_unbounded_array.h> 43 #include <__type_traits/nat.h> 44 #include <__type_traits/negation.h> 45 #include <__type_traits/remove_extent.h> 46 #include <__type_traits/remove_reference.h> 47 #include <__utility/declval.h> 48 #include <__utility/forward.h> 49 #include <__utility/move.h> 50 #include <__utility/swap.h> 51 #include <__verbose_abort> 52 #include <cstddef> 53 #include <new> 54 #include <typeinfo> 55 #if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER) 56 # include <__atomic/memory_order.h> 57 #endif 58 59 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 60 # pragma GCC system_header 61 #endif 62 63 _LIBCPP_PUSH_MACROS 64 #include <__undef_macros> 65 66 _LIBCPP_BEGIN_NAMESPACE_STD 67 68 // NOTE: Relaxed and acq/rel atomics (for increment and decrement respectively) 69 // should be sufficient for thread safety. 70 // See https://llvm.org/PR22803 71 #if defined(__clang__) && __has_builtin(__atomic_add_fetch) && defined(__ATOMIC_RELAXED) && defined(__ATOMIC_ACQ_REL) 72 # define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT 73 #elif defined(_LIBCPP_COMPILER_GCC) 74 # define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT 75 #endif 76 77 template <class _ValueType> 78 inline _LIBCPP_HIDE_FROM_ABI _ValueType __libcpp_relaxed_load(_ValueType const* __value) { 79 #if !defined(_LIBCPP_HAS_NO_THREADS) && defined(__ATOMIC_RELAXED) && \ 80 (__has_builtin(__atomic_load_n) || defined(_LIBCPP_COMPILER_GCC)) 81 return __atomic_load_n(__value, __ATOMIC_RELAXED); 82 #else 83 return *__value; 84 #endif 85 } 86 87 template <class _ValueType> 88 inline _LIBCPP_HIDE_FROM_ABI _ValueType __libcpp_acquire_load(_ValueType const* __value) { 89 #if !defined(_LIBCPP_HAS_NO_THREADS) && defined(__ATOMIC_ACQUIRE) && \ 90 (__has_builtin(__atomic_load_n) || defined(_LIBCPP_COMPILER_GCC)) 91 return __atomic_load_n(__value, __ATOMIC_ACQUIRE); 92 #else 93 return *__value; 94 #endif 95 } 96 97 template <class _Tp> 98 inline _LIBCPP_HIDE_FROM_ABI _Tp __libcpp_atomic_refcount_increment(_Tp& __t) _NOEXCEPT { 99 #if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS) 100 return __atomic_add_fetch(&__t, 1, __ATOMIC_RELAXED); 101 #else 102 return __t += 1; 103 #endif 104 } 105 106 template <class _Tp> 107 inline _LIBCPP_HIDE_FROM_ABI _Tp __libcpp_atomic_refcount_decrement(_Tp& __t) _NOEXCEPT { 108 #if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS) 109 return __atomic_add_fetch(&__t, -1, __ATOMIC_ACQ_REL); 110 #else 111 return __t -= 1; 112 #endif 113 } 114 115 class _LIBCPP_EXPORTED_FROM_ABI bad_weak_ptr : public std::exception { 116 public: 117 _LIBCPP_HIDE_FROM_ABI bad_weak_ptr() _NOEXCEPT = default; 118 _LIBCPP_HIDE_FROM_ABI bad_weak_ptr(const bad_weak_ptr&) _NOEXCEPT = default; 119 _LIBCPP_HIDE_FROM_ABI bad_weak_ptr& operator=(const bad_weak_ptr&) _NOEXCEPT = default; 120 ~bad_weak_ptr() _NOEXCEPT override; 121 const char* what() const _NOEXCEPT override; 122 }; 123 124 _LIBCPP_NORETURN inline _LIBCPP_HIDE_FROM_ABI void __throw_bad_weak_ptr() { 125 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 126 throw bad_weak_ptr(); 127 #else 128 _LIBCPP_VERBOSE_ABORT("bad_weak_ptr was thrown in -fno-exceptions mode"); 129 #endif 130 } 131 132 template <class _Tp> 133 class _LIBCPP_TEMPLATE_VIS weak_ptr; 134 135 class _LIBCPP_EXPORTED_FROM_ABI __shared_count { 136 __shared_count(const __shared_count&); 137 __shared_count& operator=(const __shared_count&); 138 139 protected: 140 long __shared_owners_; 141 virtual ~__shared_count(); 142 143 private: 144 virtual void __on_zero_shared() _NOEXCEPT = 0; 145 146 public: 147 _LIBCPP_HIDE_FROM_ABI explicit __shared_count(long __refs = 0) _NOEXCEPT : __shared_owners_(__refs) {} 148 149 #if defined(_LIBCPP_SHARED_PTR_DEFINE_LEGACY_INLINE_FUNCTIONS) 150 void __add_shared() noexcept; 151 bool __release_shared() noexcept; 152 #else 153 _LIBCPP_HIDE_FROM_ABI void __add_shared() _NOEXCEPT { __libcpp_atomic_refcount_increment(__shared_owners_); } 154 _LIBCPP_HIDE_FROM_ABI bool __release_shared() _NOEXCEPT { 155 if (__libcpp_atomic_refcount_decrement(__shared_owners_) == -1) { 156 __on_zero_shared(); 157 return true; 158 } 159 return false; 160 } 161 #endif 162 _LIBCPP_HIDE_FROM_ABI long use_count() const _NOEXCEPT { return __libcpp_relaxed_load(&__shared_owners_) + 1; } 163 }; 164 165 class _LIBCPP_EXPORTED_FROM_ABI __shared_weak_count : private __shared_count { 166 long __shared_weak_owners_; 167 168 public: 169 _LIBCPP_HIDE_FROM_ABI explicit __shared_weak_count(long __refs = 0) _NOEXCEPT 170 : __shared_count(__refs), 171 __shared_weak_owners_(__refs) {} 172 173 protected: 174 ~__shared_weak_count() override; 175 176 public: 177 #if defined(_LIBCPP_SHARED_PTR_DEFINE_LEGACY_INLINE_FUNCTIONS) 178 void __add_shared() noexcept; 179 void __add_weak() noexcept; 180 void __release_shared() noexcept; 181 #else 182 _LIBCPP_HIDE_FROM_ABI void __add_shared() _NOEXCEPT { __shared_count::__add_shared(); } 183 _LIBCPP_HIDE_FROM_ABI void __add_weak() _NOEXCEPT { __libcpp_atomic_refcount_increment(__shared_weak_owners_); } 184 _LIBCPP_HIDE_FROM_ABI void __release_shared() _NOEXCEPT { 185 if (__shared_count::__release_shared()) 186 __release_weak(); 187 } 188 #endif 189 void __release_weak() _NOEXCEPT; 190 _LIBCPP_HIDE_FROM_ABI long use_count() const _NOEXCEPT { return __shared_count::use_count(); } 191 __shared_weak_count* lock() _NOEXCEPT; 192 193 virtual const void* __get_deleter(const type_info&) const _NOEXCEPT; 194 195 private: 196 virtual void __on_zero_shared_weak() _NOEXCEPT = 0; 197 }; 198 199 template <class _Tp, class _Dp, class _Alloc> 200 class __shared_ptr_pointer : public __shared_weak_count { 201 __compressed_pair<__compressed_pair<_Tp, _Dp>, _Alloc> __data_; 202 203 public: 204 _LIBCPP_HIDE_FROM_ABI __shared_ptr_pointer(_Tp __p, _Dp __d, _Alloc __a) 205 : __data_(__compressed_pair<_Tp, _Dp>(__p, std::move(__d)), std::move(__a)) {} 206 207 #ifndef _LIBCPP_HAS_NO_RTTI 208 _LIBCPP_HIDE_FROM_ABI_VIRTUAL const void* __get_deleter(const type_info&) const _NOEXCEPT override; 209 #endif 210 211 private: 212 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override; 213 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared_weak() _NOEXCEPT override; 214 }; 215 216 #ifndef _LIBCPP_HAS_NO_RTTI 217 218 template <class _Tp, class _Dp, class _Alloc> 219 const void* __shared_ptr_pointer<_Tp, _Dp, _Alloc>::__get_deleter(const type_info& __t) const _NOEXCEPT { 220 return __t == typeid(_Dp) ? std::addressof(__data_.first().second()) : nullptr; 221 } 222 223 #endif // _LIBCPP_HAS_NO_RTTI 224 225 template <class _Tp, class _Dp, class _Alloc> 226 void __shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared() _NOEXCEPT { 227 __data_.first().second()(__data_.first().first()); 228 __data_.first().second().~_Dp(); 229 } 230 231 template <class _Tp, class _Dp, class _Alloc> 232 void __shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT { 233 typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_pointer>::type _Al; 234 typedef allocator_traits<_Al> _ATraits; 235 typedef pointer_traits<typename _ATraits::pointer> _PTraits; 236 237 _Al __a(__data_.second()); 238 __data_.second().~_Alloc(); 239 __a.deallocate(_PTraits::pointer_to(*this), 1); 240 } 241 242 // This tag is used to instantiate an allocator type. The various shared_ptr control blocks 243 // detect that the allocator has been instantiated for this type and perform alternative 244 // initialization/destruction based on that. 245 struct __for_overwrite_tag {}; 246 247 template <class _Tp, class _Alloc> 248 struct __shared_ptr_emplace : __shared_weak_count { 249 template <class... _Args, 250 class _Allocator = _Alloc, 251 __enable_if_t<is_same<typename _Allocator::value_type, __for_overwrite_tag>::value, int> = 0> 252 _LIBCPP_HIDE_FROM_ABI explicit __shared_ptr_emplace(_Alloc __a, _Args&&...) : __storage_(std::move(__a)) { 253 static_assert( 254 sizeof...(_Args) == 0, "No argument should be provided to the control block when using _for_overwrite"); 255 ::new ((void*)__get_elem()) _Tp; 256 } 257 258 template <class... _Args, 259 class _Allocator = _Alloc, 260 __enable_if_t<!is_same<typename _Allocator::value_type, __for_overwrite_tag>::value, int> = 0> 261 _LIBCPP_HIDE_FROM_ABI explicit __shared_ptr_emplace(_Alloc __a, _Args&&... __args) : __storage_(std::move(__a)) { 262 using _TpAlloc = typename __allocator_traits_rebind<_Alloc, __remove_cv_t<_Tp> >::type; 263 _TpAlloc __tmp(*__get_alloc()); 264 allocator_traits<_TpAlloc>::construct(__tmp, __get_elem(), std::forward<_Args>(__args)...); 265 } 266 267 _LIBCPP_HIDE_FROM_ABI _Alloc* __get_alloc() _NOEXCEPT { return __storage_.__get_alloc(); } 268 269 _LIBCPP_HIDE_FROM_ABI _Tp* __get_elem() _NOEXCEPT { return __storage_.__get_elem(); } 270 271 private: 272 template <class _Allocator = _Alloc, 273 __enable_if_t<is_same<typename _Allocator::value_type, __for_overwrite_tag>::value, int> = 0> 274 _LIBCPP_HIDE_FROM_ABI void __on_zero_shared_impl() _NOEXCEPT { 275 __get_elem()->~_Tp(); 276 } 277 278 template <class _Allocator = _Alloc, 279 __enable_if_t<!is_same<typename _Allocator::value_type, __for_overwrite_tag>::value, int> = 0> 280 _LIBCPP_HIDE_FROM_ABI void __on_zero_shared_impl() _NOEXCEPT { 281 using _TpAlloc = typename __allocator_traits_rebind<_Allocator, __remove_cv_t<_Tp> >::type; 282 _TpAlloc __tmp(*__get_alloc()); 283 allocator_traits<_TpAlloc>::destroy(__tmp, __get_elem()); 284 } 285 286 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override { __on_zero_shared_impl(); } 287 288 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared_weak() _NOEXCEPT override { 289 using _ControlBlockAlloc = typename __allocator_traits_rebind<_Alloc, __shared_ptr_emplace>::type; 290 using _ControlBlockPointer = typename allocator_traits<_ControlBlockAlloc>::pointer; 291 _ControlBlockAlloc __tmp(*__get_alloc()); 292 __storage_.~_Storage(); 293 allocator_traits<_ControlBlockAlloc>::deallocate(__tmp, pointer_traits<_ControlBlockPointer>::pointer_to(*this), 1); 294 } 295 296 // This class implements the control block for non-array shared pointers created 297 // through `std::allocate_shared` and `std::make_shared`. 298 // 299 // In previous versions of the library, we used a compressed pair to store 300 // both the _Alloc and the _Tp. This implies using EBO, which is incompatible 301 // with Allocator construction for _Tp. To allow implementing P0674 in C++20, 302 // we now use a properly aligned char buffer while making sure that we maintain 303 // the same layout that we had when we used a compressed pair. 304 using _CompressedPair = __compressed_pair<_Alloc, _Tp>; 305 struct _ALIGNAS_TYPE(_CompressedPair) _Storage { 306 char __blob_[sizeof(_CompressedPair)]; 307 308 _LIBCPP_HIDE_FROM_ABI explicit _Storage(_Alloc&& __a) { ::new ((void*)__get_alloc()) _Alloc(std::move(__a)); } 309 _LIBCPP_HIDE_FROM_ABI ~_Storage() { __get_alloc()->~_Alloc(); } 310 _LIBCPP_HIDE_FROM_ABI _Alloc* __get_alloc() _NOEXCEPT { 311 _CompressedPair* __as_pair = reinterpret_cast<_CompressedPair*>(__blob_); 312 typename _CompressedPair::_Base1* __first = _CompressedPair::__get_first_base(__as_pair); 313 _Alloc* __alloc = reinterpret_cast<_Alloc*>(__first); 314 return __alloc; 315 } 316 _LIBCPP_HIDE_FROM_ABI _LIBCPP_NO_CFI _Tp* __get_elem() _NOEXCEPT { 317 _CompressedPair* __as_pair = reinterpret_cast<_CompressedPair*>(__blob_); 318 typename _CompressedPair::_Base2* __second = _CompressedPair::__get_second_base(__as_pair); 319 _Tp* __elem = reinterpret_cast<_Tp*>(__second); 320 return __elem; 321 } 322 }; 323 324 static_assert(_LIBCPP_ALIGNOF(_Storage) == _LIBCPP_ALIGNOF(_CompressedPair), ""); 325 static_assert(sizeof(_Storage) == sizeof(_CompressedPair), ""); 326 _Storage __storage_; 327 }; 328 329 struct __shared_ptr_dummy_rebind_allocator_type; 330 template <> 331 class _LIBCPP_TEMPLATE_VIS allocator<__shared_ptr_dummy_rebind_allocator_type> { 332 public: 333 template <class _Other> 334 struct rebind { 335 typedef allocator<_Other> other; 336 }; 337 }; 338 339 template <class _Tp> 340 class _LIBCPP_TEMPLATE_VIS enable_shared_from_this; 341 342 // http://eel.is/c++draft/util.sharedptr#util.smartptr.shared.general-6 343 // A pointer type Y* is said to be compatible with a pointer type T* 344 // when either Y* is convertible to T* or Y is U[N] and T is cv U[]. 345 #if _LIBCPP_STD_VER >= 17 346 template <class _Yp, class _Tp> 347 struct __bounded_convertible_to_unbounded : false_type {}; 348 349 template <class _Up, std::size_t _Np, class _Tp> 350 struct __bounded_convertible_to_unbounded<_Up[_Np], _Tp> : is_same<__remove_cv_t<_Tp>, _Up[]> {}; 351 352 template <class _Yp, class _Tp> 353 struct __compatible_with : _Or< is_convertible<_Yp*, _Tp*>, __bounded_convertible_to_unbounded<_Yp, _Tp> > {}; 354 #else 355 template <class _Yp, class _Tp> 356 struct __compatible_with : is_convertible<_Yp*, _Tp*> {}; 357 #endif // _LIBCPP_STD_VER >= 17 358 359 // Constructors that take raw pointers have a different set of "compatible" constraints 360 // http://eel.is/c++draft/util.sharedptr#util.smartptr.shared.const-9.1 361 // - If T is an array type, then either T is U[N] and Y(*)[N] is convertible to T*, 362 // or T is U[] and Y(*)[] is convertible to T*. 363 // - If T is not an array type, then Y* is convertible to T*. 364 #if _LIBCPP_STD_VER >= 17 365 template <class _Yp, class _Tp, class = void> 366 struct __raw_pointer_compatible_with : _And< _Not<is_array<_Tp>>, is_convertible<_Yp*, _Tp*> > {}; 367 368 template <class _Yp, class _Up, std::size_t _Np> 369 struct __raw_pointer_compatible_with<_Yp, _Up[_Np], __enable_if_t< is_convertible<_Yp (*)[_Np], _Up (*)[_Np]>::value> > 370 : true_type {}; 371 372 template <class _Yp, class _Up> 373 struct __raw_pointer_compatible_with<_Yp, _Up[], __enable_if_t< is_convertible<_Yp (*)[], _Up (*)[]>::value> > 374 : true_type {}; 375 376 #else 377 template <class _Yp, class _Tp> 378 struct __raw_pointer_compatible_with : is_convertible<_Yp*, _Tp*> {}; 379 #endif // _LIBCPP_STD_VER >= 17 380 381 template <class _Ptr, class = void> 382 struct __is_deletable : false_type {}; 383 template <class _Ptr> 384 struct __is_deletable<_Ptr, decltype(delete std::declval<_Ptr>())> : true_type {}; 385 386 template <class _Ptr, class = void> 387 struct __is_array_deletable : false_type {}; 388 template <class _Ptr> 389 struct __is_array_deletable<_Ptr, decltype(delete[] std::declval<_Ptr>())> : true_type {}; 390 391 template <class _Dp, class _Pt, class = decltype(std::declval<_Dp>()(std::declval<_Pt>()))> 392 true_type __well_formed_deleter_test(int); 393 394 template <class, class> 395 false_type __well_formed_deleter_test(...); 396 397 template <class _Dp, class _Pt> 398 struct __well_formed_deleter : decltype(std::__well_formed_deleter_test<_Dp, _Pt>(0)) {}; 399 400 template <class _Dp, class _Yp, class _Tp> 401 struct __shared_ptr_deleter_ctor_reqs { 402 static const bool value = __raw_pointer_compatible_with<_Yp, _Tp>::value && is_move_constructible<_Dp>::value && 403 __well_formed_deleter<_Dp, _Yp*>::value; 404 }; 405 406 template <class _Dp> 407 using __shared_ptr_nullptr_deleter_ctor_reqs = _And<is_move_constructible<_Dp>, __well_formed_deleter<_Dp, nullptr_t> >; 408 409 #if defined(_LIBCPP_ABI_ENABLE_SHARED_PTR_TRIVIAL_ABI) 410 # define _LIBCPP_SHARED_PTR_TRIVIAL_ABI __attribute__((__trivial_abi__)) 411 #else 412 # define _LIBCPP_SHARED_PTR_TRIVIAL_ABI 413 #endif 414 415 template <class _Tp> 416 class _LIBCPP_SHARED_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS shared_ptr { 417 struct __nullptr_sfinae_tag {}; 418 419 public: 420 #if _LIBCPP_STD_VER >= 17 421 typedef weak_ptr<_Tp> weak_type; 422 typedef remove_extent_t<_Tp> element_type; 423 #else 424 typedef _Tp element_type; 425 #endif 426 427 // A shared_ptr contains only two raw pointers which point to the heap and move constructing already doesn't require 428 // any bookkeeping, so it's always trivially relocatable. 429 using __trivially_relocatable = shared_ptr; 430 431 private: 432 element_type* __ptr_; 433 __shared_weak_count* __cntrl_; 434 435 public: 436 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR shared_ptr() _NOEXCEPT : __ptr_(nullptr), __cntrl_(nullptr) {} 437 438 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR shared_ptr(nullptr_t) _NOEXCEPT : __ptr_(nullptr), __cntrl_(nullptr) {} 439 440 template <class _Yp, 441 __enable_if_t< _And< __raw_pointer_compatible_with<_Yp, _Tp> 442 // In C++03 we get errors when trying to do SFINAE with the 443 // delete operator, so we always pretend that it's deletable. 444 // The same happens on GCC. 445 #if !defined(_LIBCPP_CXX03_LANG) && !defined(_LIBCPP_COMPILER_GCC) 446 , 447 _If<is_array<_Tp>::value, __is_array_deletable<_Yp*>, __is_deletable<_Yp*> > 448 #endif 449 >::value, 450 int> = 0> 451 _LIBCPP_HIDE_FROM_ABI explicit shared_ptr(_Yp* __p) : __ptr_(__p) { 452 unique_ptr<_Yp> __hold(__p); 453 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT; 454 typedef __shared_ptr_pointer<_Yp*, __shared_ptr_default_delete<_Tp, _Yp>, _AllocT> _CntrlBlk; 455 __cntrl_ = new _CntrlBlk(__p, __shared_ptr_default_delete<_Tp, _Yp>(), _AllocT()); 456 __hold.release(); 457 __enable_weak_this(__p, __p); 458 } 459 460 template <class _Yp, class _Dp, __enable_if_t<__shared_ptr_deleter_ctor_reqs<_Dp, _Yp, _Tp>::value, int> = 0> 461 _LIBCPP_HIDE_FROM_ABI shared_ptr(_Yp* __p, _Dp __d) : __ptr_(__p) { 462 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 463 try { 464 #endif // _LIBCPP_HAS_NO_EXCEPTIONS 465 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT; 466 typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT> _CntrlBlk; 467 #ifndef _LIBCPP_CXX03_LANG 468 __cntrl_ = new _CntrlBlk(__p, std::move(__d), _AllocT()); 469 #else 470 __cntrl_ = new _CntrlBlk(__p, __d, _AllocT()); 471 #endif // not _LIBCPP_CXX03_LANG 472 __enable_weak_this(__p, __p); 473 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 474 } catch (...) { 475 __d(__p); 476 throw; 477 } 478 #endif // _LIBCPP_HAS_NO_EXCEPTIONS 479 } 480 481 template <class _Yp, 482 class _Dp, 483 class _Alloc, 484 __enable_if_t<__shared_ptr_deleter_ctor_reqs<_Dp, _Yp, _Tp>::value, int> = 0> 485 _LIBCPP_HIDE_FROM_ABI shared_ptr(_Yp* __p, _Dp __d, _Alloc __a) : __ptr_(__p) { 486 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 487 try { 488 #endif // _LIBCPP_HAS_NO_EXCEPTIONS 489 typedef __shared_ptr_pointer<_Yp*, _Dp, _Alloc> _CntrlBlk; 490 typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2; 491 typedef __allocator_destructor<_A2> _D2; 492 _A2 __a2(__a); 493 unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1)); 494 ::new ((void*)std::addressof(*__hold2.get())) 495 #ifndef _LIBCPP_CXX03_LANG 496 _CntrlBlk(__p, std::move(__d), __a); 497 #else 498 _CntrlBlk(__p, __d, __a); 499 #endif // not _LIBCPP_CXX03_LANG 500 __cntrl_ = std::addressof(*__hold2.release()); 501 __enable_weak_this(__p, __p); 502 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 503 } catch (...) { 504 __d(__p); 505 throw; 506 } 507 #endif // _LIBCPP_HAS_NO_EXCEPTIONS 508 } 509 510 template <class _Dp> 511 _LIBCPP_HIDE_FROM_ABI shared_ptr( 512 nullptr_t __p, 513 _Dp __d, 514 __enable_if_t<__shared_ptr_nullptr_deleter_ctor_reqs<_Dp>::value, __nullptr_sfinae_tag> = __nullptr_sfinae_tag()) 515 : __ptr_(nullptr) { 516 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 517 try { 518 #endif // _LIBCPP_HAS_NO_EXCEPTIONS 519 typedef typename __shared_ptr_default_allocator<_Tp>::type _AllocT; 520 typedef __shared_ptr_pointer<nullptr_t, _Dp, _AllocT> _CntrlBlk; 521 #ifndef _LIBCPP_CXX03_LANG 522 __cntrl_ = new _CntrlBlk(__p, std::move(__d), _AllocT()); 523 #else 524 __cntrl_ = new _CntrlBlk(__p, __d, _AllocT()); 525 #endif // not _LIBCPP_CXX03_LANG 526 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 527 } catch (...) { 528 __d(__p); 529 throw; 530 } 531 #endif // _LIBCPP_HAS_NO_EXCEPTIONS 532 } 533 534 template <class _Dp, class _Alloc> 535 _LIBCPP_HIDE_FROM_ABI shared_ptr( 536 nullptr_t __p, 537 _Dp __d, 538 _Alloc __a, 539 __enable_if_t<__shared_ptr_nullptr_deleter_ctor_reqs<_Dp>::value, __nullptr_sfinae_tag> = __nullptr_sfinae_tag()) 540 : __ptr_(nullptr) { 541 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 542 try { 543 #endif // _LIBCPP_HAS_NO_EXCEPTIONS 544 typedef __shared_ptr_pointer<nullptr_t, _Dp, _Alloc> _CntrlBlk; 545 typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2; 546 typedef __allocator_destructor<_A2> _D2; 547 _A2 __a2(__a); 548 unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1)); 549 ::new ((void*)std::addressof(*__hold2.get())) 550 #ifndef _LIBCPP_CXX03_LANG 551 _CntrlBlk(__p, std::move(__d), __a); 552 #else 553 _CntrlBlk(__p, __d, __a); 554 #endif // not _LIBCPP_CXX03_LANG 555 __cntrl_ = std::addressof(*__hold2.release()); 556 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 557 } catch (...) { 558 __d(__p); 559 throw; 560 } 561 #endif // _LIBCPP_HAS_NO_EXCEPTIONS 562 } 563 564 template <class _Yp> 565 _LIBCPP_HIDE_FROM_ABI shared_ptr(const shared_ptr<_Yp>& __r, element_type* __p) _NOEXCEPT 566 : __ptr_(__p), 567 __cntrl_(__r.__cntrl_) { 568 if (__cntrl_) 569 __cntrl_->__add_shared(); 570 } 571 572 // LWG-2996 573 // We don't backport because it is an evolutionary change. 574 #if _LIBCPP_STD_VER >= 20 575 template <class _Yp> 576 _LIBCPP_HIDE_FROM_ABI shared_ptr(shared_ptr<_Yp>&& __r, element_type* __p) noexcept 577 : __ptr_(__p), __cntrl_(__r.__cntrl_) { 578 __r.__ptr_ = nullptr; 579 __r.__cntrl_ = nullptr; 580 } 581 #endif 582 583 _LIBCPP_HIDE_FROM_ABI shared_ptr(const shared_ptr& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) { 584 if (__cntrl_) 585 __cntrl_->__add_shared(); 586 } 587 588 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0> 589 _LIBCPP_HIDE_FROM_ABI shared_ptr(const shared_ptr<_Yp>& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) { 590 if (__cntrl_) 591 __cntrl_->__add_shared(); 592 } 593 594 _LIBCPP_HIDE_FROM_ABI shared_ptr(shared_ptr&& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) { 595 __r.__ptr_ = nullptr; 596 __r.__cntrl_ = nullptr; 597 } 598 599 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0> 600 _LIBCPP_HIDE_FROM_ABI shared_ptr(shared_ptr<_Yp>&& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) { 601 __r.__ptr_ = nullptr; 602 __r.__cntrl_ = nullptr; 603 } 604 605 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0> 606 _LIBCPP_HIDE_FROM_ABI explicit shared_ptr(const weak_ptr<_Yp>& __r) 607 : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_ ? __r.__cntrl_->lock() : __r.__cntrl_) { 608 if (__cntrl_ == nullptr) 609 __throw_bad_weak_ptr(); 610 } 611 612 #if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR) 613 template <class _Yp, __enable_if_t<is_convertible<_Yp*, element_type*>::value, int> = 0> 614 _LIBCPP_HIDE_FROM_ABI shared_ptr(auto_ptr<_Yp>&& __r) : __ptr_(__r.get()) { 615 typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<__remove_cv_t<_Yp> > > _CntrlBlk; 616 __cntrl_ = new _CntrlBlk(__r.get(), default_delete<_Yp>(), allocator<__remove_cv_t<_Yp> >()); 617 __enable_weak_this(__r.get(), __r.get()); 618 __r.release(); 619 } 620 #endif 621 622 template <class _Yp, 623 class _Dp, 624 __enable_if_t<!is_lvalue_reference<_Dp>::value && __compatible_with<_Yp, _Tp>::value && 625 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value, 626 int> = 0> 627 _LIBCPP_HIDE_FROM_ABI shared_ptr(unique_ptr<_Yp, _Dp>&& __r) : __ptr_(__r.get()) { 628 #if _LIBCPP_STD_VER >= 14 629 if (__ptr_ == nullptr) 630 __cntrl_ = nullptr; 631 else 632 #endif 633 { 634 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT; 635 typedef __shared_ptr_pointer<typename unique_ptr<_Yp, _Dp>::pointer, _Dp, _AllocT> _CntrlBlk; 636 __cntrl_ = new _CntrlBlk(__r.get(), std::move(__r.get_deleter()), _AllocT()); 637 __enable_weak_this(__r.get(), __r.get()); 638 } 639 __r.release(); 640 } 641 642 template <class _Yp, 643 class _Dp, 644 class = void, 645 __enable_if_t<is_lvalue_reference<_Dp>::value && __compatible_with<_Yp, _Tp>::value && 646 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value, 647 int> = 0> 648 _LIBCPP_HIDE_FROM_ABI shared_ptr(unique_ptr<_Yp, _Dp>&& __r) : __ptr_(__r.get()) { 649 #if _LIBCPP_STD_VER >= 14 650 if (__ptr_ == nullptr) 651 __cntrl_ = nullptr; 652 else 653 #endif 654 { 655 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT; 656 typedef __shared_ptr_pointer<typename unique_ptr<_Yp, _Dp>::pointer, 657 reference_wrapper<__libcpp_remove_reference_t<_Dp> >, 658 _AllocT> 659 _CntrlBlk; 660 __cntrl_ = new _CntrlBlk(__r.get(), std::ref(__r.get_deleter()), _AllocT()); 661 __enable_weak_this(__r.get(), __r.get()); 662 } 663 __r.release(); 664 } 665 666 _LIBCPP_HIDE_FROM_ABI ~shared_ptr() { 667 if (__cntrl_) 668 __cntrl_->__release_shared(); 669 } 670 671 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(const shared_ptr& __r) _NOEXCEPT { 672 shared_ptr(__r).swap(*this); 673 return *this; 674 } 675 676 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0> 677 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT { 678 shared_ptr(__r).swap(*this); 679 return *this; 680 } 681 682 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(shared_ptr&& __r) _NOEXCEPT { 683 shared_ptr(std::move(__r)).swap(*this); 684 return *this; 685 } 686 687 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0> 688 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(shared_ptr<_Yp>&& __r) { 689 shared_ptr(std::move(__r)).swap(*this); 690 return *this; 691 } 692 693 #if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR) 694 template <class _Yp, 695 __enable_if_t<!is_array<_Yp>::value && is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value, 696 int> = 0> 697 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(auto_ptr<_Yp>&& __r) { 698 shared_ptr(std::move(__r)).swap(*this); 699 return *this; 700 } 701 #endif 702 703 template <class _Yp, 704 class _Dp, 705 __enable_if_t<_And< __compatible_with<_Yp, _Tp>, 706 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*> >::value, 707 int> = 0> 708 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(unique_ptr<_Yp, _Dp>&& __r) { 709 shared_ptr(std::move(__r)).swap(*this); 710 return *this; 711 } 712 713 _LIBCPP_HIDE_FROM_ABI void swap(shared_ptr& __r) _NOEXCEPT { 714 std::swap(__ptr_, __r.__ptr_); 715 std::swap(__cntrl_, __r.__cntrl_); 716 } 717 718 _LIBCPP_HIDE_FROM_ABI void reset() _NOEXCEPT { shared_ptr().swap(*this); } 719 720 template <class _Yp, __enable_if_t<__raw_pointer_compatible_with<_Yp, _Tp>::value, int> = 0> 721 _LIBCPP_HIDE_FROM_ABI void reset(_Yp* __p) { 722 shared_ptr(__p).swap(*this); 723 } 724 725 template <class _Yp, class _Dp, __enable_if_t<__shared_ptr_deleter_ctor_reqs<_Dp, _Yp, _Tp>::value, int> = 0> 726 _LIBCPP_HIDE_FROM_ABI void reset(_Yp* __p, _Dp __d) { 727 shared_ptr(__p, __d).swap(*this); 728 } 729 730 template <class _Yp, 731 class _Dp, 732 class _Alloc, 733 __enable_if_t<__shared_ptr_deleter_ctor_reqs<_Dp, _Yp, _Tp>::value, int> = 0> 734 _LIBCPP_HIDE_FROM_ABI void reset(_Yp* __p, _Dp __d, _Alloc __a) { 735 shared_ptr(__p, __d, __a).swap(*this); 736 } 737 738 _LIBCPP_HIDE_FROM_ABI element_type* get() const _NOEXCEPT { return __ptr_; } 739 740 _LIBCPP_HIDE_FROM_ABI __add_lvalue_reference_t<element_type> operator*() const _NOEXCEPT { return *__ptr_; } 741 742 _LIBCPP_HIDE_FROM_ABI element_type* operator->() const _NOEXCEPT { 743 static_assert(!is_array<_Tp>::value, "std::shared_ptr<T>::operator-> is only valid when T is not an array type."); 744 return __ptr_; 745 } 746 747 _LIBCPP_HIDE_FROM_ABI long use_count() const _NOEXCEPT { return __cntrl_ ? __cntrl_->use_count() : 0; } 748 749 #if _LIBCPP_STD_VER < 20 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_SHARED_PTR_UNIQUE) 750 _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_HIDE_FROM_ABI bool unique() const _NOEXCEPT { return use_count() == 1; } 751 #endif 752 753 _LIBCPP_HIDE_FROM_ABI explicit operator bool() const _NOEXCEPT { return get() != nullptr; } 754 755 template <class _Up> 756 _LIBCPP_HIDE_FROM_ABI bool owner_before(shared_ptr<_Up> const& __p) const _NOEXCEPT { 757 return __cntrl_ < __p.__cntrl_; 758 } 759 760 template <class _Up> 761 _LIBCPP_HIDE_FROM_ABI bool owner_before(weak_ptr<_Up> const& __p) const _NOEXCEPT { 762 return __cntrl_ < __p.__cntrl_; 763 } 764 765 _LIBCPP_HIDE_FROM_ABI bool __owner_equivalent(const shared_ptr& __p) const { return __cntrl_ == __p.__cntrl_; } 766 767 #if _LIBCPP_STD_VER >= 17 768 _LIBCPP_HIDE_FROM_ABI __add_lvalue_reference_t<element_type> operator[](ptrdiff_t __i) const { 769 static_assert(is_array<_Tp>::value, "std::shared_ptr<T>::operator[] is only valid when T is an array type."); 770 return __ptr_[__i]; 771 } 772 #endif 773 774 #ifndef _LIBCPP_HAS_NO_RTTI 775 template <class _Dp> 776 _LIBCPP_HIDE_FROM_ABI _Dp* __get_deleter() const _NOEXCEPT { 777 return static_cast<_Dp*>(__cntrl_ ? const_cast<void*>(__cntrl_->__get_deleter(typeid(_Dp))) : nullptr); 778 } 779 #endif // _LIBCPP_HAS_NO_RTTI 780 781 template <class _Yp, class _CntrlBlk> 782 _LIBCPP_HIDE_FROM_ABI static shared_ptr<_Tp> __create_with_control_block(_Yp* __p, _CntrlBlk* __cntrl) _NOEXCEPT { 783 shared_ptr<_Tp> __r; 784 __r.__ptr_ = __p; 785 __r.__cntrl_ = __cntrl; 786 __r.__enable_weak_this(__r.__ptr_, __r.__ptr_); 787 return __r; 788 } 789 790 private: 791 template <class _Yp, bool = is_function<_Yp>::value> 792 struct __shared_ptr_default_allocator { 793 typedef allocator<__remove_cv_t<_Yp> > type; 794 }; 795 796 template <class _Yp> 797 struct __shared_ptr_default_allocator<_Yp, true> { 798 typedef allocator<__shared_ptr_dummy_rebind_allocator_type> type; 799 }; 800 801 template <class _Yp, 802 class _OrigPtr, 803 __enable_if_t<is_convertible<_OrigPtr*, const enable_shared_from_this<_Yp>*>::value, int> = 0> 804 _LIBCPP_HIDE_FROM_ABI void __enable_weak_this(const enable_shared_from_this<_Yp>* __e, _OrigPtr* __ptr) _NOEXCEPT { 805 typedef __remove_cv_t<_Yp> _RawYp; 806 if (__e && __e->__weak_this_.expired()) { 807 __e->__weak_this_ = shared_ptr<_RawYp>(*this, const_cast<_RawYp*>(static_cast<const _Yp*>(__ptr))); 808 } 809 } 810 811 _LIBCPP_HIDE_FROM_ABI void __enable_weak_this(...) _NOEXCEPT {} 812 813 template <class, class _Yp> 814 struct __shared_ptr_default_delete : default_delete<_Yp> {}; 815 816 template <class _Yp, class _Un, size_t _Sz> 817 struct __shared_ptr_default_delete<_Yp[_Sz], _Un> : default_delete<_Yp[]> {}; 818 819 template <class _Yp, class _Un> 820 struct __shared_ptr_default_delete<_Yp[], _Un> : default_delete<_Yp[]> {}; 821 822 template <class _Up> 823 friend class _LIBCPP_TEMPLATE_VIS shared_ptr; 824 template <class _Up> 825 friend class _LIBCPP_TEMPLATE_VIS weak_ptr; 826 }; 827 828 #if _LIBCPP_STD_VER >= 17 829 template <class _Tp> 830 shared_ptr(weak_ptr<_Tp>) -> shared_ptr<_Tp>; 831 template <class _Tp, class _Dp> 832 shared_ptr(unique_ptr<_Tp, _Dp>) -> shared_ptr<_Tp>; 833 #endif 834 835 // 836 // std::allocate_shared and std::make_shared 837 // 838 template <class _Tp, class _Alloc, class... _Args, __enable_if_t<!is_array<_Tp>::value, int> = 0> 839 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> allocate_shared(const _Alloc& __a, _Args&&... __args) { 840 using _ControlBlock = __shared_ptr_emplace<_Tp, _Alloc>; 841 using _ControlBlockAllocator = typename __allocator_traits_rebind<_Alloc, _ControlBlock>::type; 842 __allocation_guard<_ControlBlockAllocator> __guard(__a, 1); 843 ::new ((void*)std::addressof(*__guard.__get())) _ControlBlock(__a, std::forward<_Args>(__args)...); 844 auto __control_block = __guard.__release_ptr(); 845 return shared_ptr<_Tp>::__create_with_control_block( 846 (*__control_block).__get_elem(), std::addressof(*__control_block)); 847 } 848 849 template <class _Tp, class... _Args, __enable_if_t<!is_array<_Tp>::value, int> = 0> 850 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> make_shared(_Args&&... __args) { 851 return std::allocate_shared<_Tp>(allocator<__remove_cv_t<_Tp> >(), std::forward<_Args>(__args)...); 852 } 853 854 #if _LIBCPP_STD_VER >= 20 855 856 template <class _Tp, class _Alloc, __enable_if_t<!is_array<_Tp>::value, int> = 0> 857 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> allocate_shared_for_overwrite(const _Alloc& __a) { 858 using _ForOverwriteAllocator = __allocator_traits_rebind_t<_Alloc, __for_overwrite_tag>; 859 _ForOverwriteAllocator __alloc(__a); 860 return std::allocate_shared<_Tp>(__alloc); 861 } 862 863 template <class _Tp, __enable_if_t<!is_array<_Tp>::value, int> = 0> 864 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> make_shared_for_overwrite() { 865 return std::allocate_shared_for_overwrite<_Tp>(allocator<__remove_cv_t<_Tp>>()); 866 } 867 868 #endif // _LIBCPP_STD_VER >= 20 869 870 #if _LIBCPP_STD_VER >= 17 871 872 template <size_t _Alignment> 873 struct __sp_aligned_storage { 874 alignas(_Alignment) char __storage[_Alignment]; 875 }; 876 877 template <class _Tp, class _Alloc> 878 struct __unbounded_array_control_block; 879 880 template <class _Tp, class _Alloc> 881 struct __unbounded_array_control_block<_Tp[], _Alloc> : __shared_weak_count { 882 _LIBCPP_HIDE_FROM_ABI constexpr _Tp* __get_data() noexcept { return __data_; } 883 884 _LIBCPP_HIDE_FROM_ABI explicit __unbounded_array_control_block( 885 _Alloc const& __alloc, size_t __count, _Tp const& __arg) 886 : __alloc_(__alloc), __count_(__count) { 887 std::__uninitialized_allocator_fill_n_multidimensional(__alloc_, std::begin(__data_), __count_, __arg); 888 } 889 890 _LIBCPP_HIDE_FROM_ABI explicit __unbounded_array_control_block(_Alloc const& __alloc, size_t __count) 891 : __alloc_(__alloc), __count_(__count) { 892 # if _LIBCPP_STD_VER >= 20 893 if constexpr (is_same_v<typename _Alloc::value_type, __for_overwrite_tag>) { 894 // We are purposefully not using an allocator-aware default construction because the spec says so. 895 // There's currently no way of expressing default initialization in an allocator-aware manner anyway. 896 std::uninitialized_default_construct_n(std::begin(__data_), __count_); 897 } else { 898 std::__uninitialized_allocator_value_construct_n_multidimensional(__alloc_, std::begin(__data_), __count_); 899 } 900 # else 901 std::__uninitialized_allocator_value_construct_n_multidimensional(__alloc_, std::begin(__data_), __count_); 902 # endif 903 } 904 905 // Returns the number of bytes required to store a control block followed by the given number 906 // of elements of _Tp, with the whole storage being aligned to a multiple of _Tp's alignment. 907 _LIBCPP_HIDE_FROM_ABI static constexpr size_t __bytes_for(size_t __elements) { 908 // When there's 0 elements, the control block alone is enough since it holds one element. 909 // Otherwise, we allocate one fewer element than requested because the control block already 910 // holds one. Also, we use the bitwise formula below to ensure that we allocate enough bytes 911 // for the whole allocation to be a multiple of _Tp's alignment. That formula is taken from [1]. 912 // 913 // [1]: https://en.wikipedia.org/wiki/Data_structure_alignment#Computing_padding 914 size_t __bytes = __elements == 0 ? sizeof(__unbounded_array_control_block) 915 : (__elements - 1) * sizeof(_Tp) + sizeof(__unbounded_array_control_block); 916 constexpr size_t __align = alignof(_Tp); 917 return (__bytes + __align - 1) & ~(__align - 1); 918 } 919 920 _LIBCPP_HIDE_FROM_ABI_VIRTUAL 921 ~__unbounded_array_control_block() override { 922 } // can't be `= default` because of the sometimes-non-trivial union member __data_ 923 924 private: 925 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override { 926 # if _LIBCPP_STD_VER >= 20 927 if constexpr (is_same_v<typename _Alloc::value_type, __for_overwrite_tag>) { 928 std::__reverse_destroy(__data_, __data_ + __count_); 929 } else { 930 __allocator_traits_rebind_t<_Alloc, _Tp> __value_alloc(__alloc_); 931 std::__allocator_destroy_multidimensional(__value_alloc, __data_, __data_ + __count_); 932 } 933 # else 934 __allocator_traits_rebind_t<_Alloc, _Tp> __value_alloc(__alloc_); 935 std::__allocator_destroy_multidimensional(__value_alloc, __data_, __data_ + __count_); 936 # endif 937 } 938 939 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared_weak() _NOEXCEPT override { 940 using _AlignedStorage = __sp_aligned_storage<alignof(__unbounded_array_control_block)>; 941 using _StorageAlloc = __allocator_traits_rebind_t<_Alloc, _AlignedStorage>; 942 using _PointerTraits = pointer_traits<typename allocator_traits<_StorageAlloc>::pointer>; 943 944 _StorageAlloc __tmp(__alloc_); 945 __alloc_.~_Alloc(); 946 size_t __size = __unbounded_array_control_block::__bytes_for(__count_); 947 _AlignedStorage* __storage = reinterpret_cast<_AlignedStorage*>(this); 948 allocator_traits<_StorageAlloc>::deallocate( 949 __tmp, _PointerTraits::pointer_to(*__storage), __size / sizeof(_AlignedStorage)); 950 } 951 952 _LIBCPP_NO_UNIQUE_ADDRESS _Alloc __alloc_; 953 size_t __count_; 954 union { 955 _Tp __data_[1]; 956 }; 957 }; 958 959 template <class _Array, class _Alloc, class... _Arg> 960 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Array> 961 __allocate_shared_unbounded_array(const _Alloc& __a, size_t __n, _Arg&&... __arg) { 962 static_assert(__libcpp_is_unbounded_array<_Array>::value); 963 // We compute the number of bytes necessary to hold the control block and the 964 // array elements. Then, we allocate an array of properly-aligned dummy structs 965 // large enough to hold the control block and array. This allows shifting the 966 // burden of aligning memory properly from us to the allocator. 967 using _ControlBlock = __unbounded_array_control_block<_Array, _Alloc>; 968 using _AlignedStorage = __sp_aligned_storage<alignof(_ControlBlock)>; 969 using _StorageAlloc = __allocator_traits_rebind_t<_Alloc, _AlignedStorage>; 970 __allocation_guard<_StorageAlloc> __guard(__a, _ControlBlock::__bytes_for(__n) / sizeof(_AlignedStorage)); 971 _ControlBlock* __control_block = reinterpret_cast<_ControlBlock*>(std::addressof(*__guard.__get())); 972 std::__construct_at(__control_block, __a, __n, std::forward<_Arg>(__arg)...); 973 __guard.__release_ptr(); 974 return shared_ptr<_Array>::__create_with_control_block(__control_block->__get_data(), __control_block); 975 } 976 977 template <class _Tp, class _Alloc> 978 struct __bounded_array_control_block; 979 980 template <class _Tp, size_t _Count, class _Alloc> 981 struct __bounded_array_control_block<_Tp[_Count], _Alloc> : __shared_weak_count { 982 _LIBCPP_HIDE_FROM_ABI constexpr _Tp* __get_data() noexcept { return __data_; } 983 984 _LIBCPP_HIDE_FROM_ABI explicit __bounded_array_control_block(_Alloc const& __alloc, _Tp const& __arg) 985 : __alloc_(__alloc) { 986 std::__uninitialized_allocator_fill_n_multidimensional(__alloc_, std::addressof(__data_[0]), _Count, __arg); 987 } 988 989 _LIBCPP_HIDE_FROM_ABI explicit __bounded_array_control_block(_Alloc const& __alloc) : __alloc_(__alloc) { 990 # if _LIBCPP_STD_VER >= 20 991 if constexpr (is_same_v<typename _Alloc::value_type, __for_overwrite_tag>) { 992 // We are purposefully not using an allocator-aware default construction because the spec says so. 993 // There's currently no way of expressing default initialization in an allocator-aware manner anyway. 994 std::uninitialized_default_construct_n(std::addressof(__data_[0]), _Count); 995 } else { 996 std::__uninitialized_allocator_value_construct_n_multidimensional(__alloc_, std::addressof(__data_[0]), _Count); 997 } 998 # else 999 std::__uninitialized_allocator_value_construct_n_multidimensional(__alloc_, std::addressof(__data_[0]), _Count); 1000 # endif 1001 } 1002 1003 _LIBCPP_HIDE_FROM_ABI_VIRTUAL 1004 ~__bounded_array_control_block() override { 1005 } // can't be `= default` because of the sometimes-non-trivial union member __data_ 1006 1007 private: 1008 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override { 1009 # if _LIBCPP_STD_VER >= 20 1010 if constexpr (is_same_v<typename _Alloc::value_type, __for_overwrite_tag>) { 1011 std::__reverse_destroy(__data_, __data_ + _Count); 1012 } else { 1013 __allocator_traits_rebind_t<_Alloc, _Tp> __value_alloc(__alloc_); 1014 std::__allocator_destroy_multidimensional(__value_alloc, __data_, __data_ + _Count); 1015 } 1016 # else 1017 __allocator_traits_rebind_t<_Alloc, _Tp> __value_alloc(__alloc_); 1018 std::__allocator_destroy_multidimensional(__value_alloc, __data_, __data_ + _Count); 1019 # endif 1020 } 1021 1022 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared_weak() _NOEXCEPT override { 1023 using _ControlBlockAlloc = __allocator_traits_rebind_t<_Alloc, __bounded_array_control_block>; 1024 using _PointerTraits = pointer_traits<typename allocator_traits<_ControlBlockAlloc>::pointer>; 1025 1026 _ControlBlockAlloc __tmp(__alloc_); 1027 __alloc_.~_Alloc(); 1028 allocator_traits<_ControlBlockAlloc>::deallocate(__tmp, _PointerTraits::pointer_to(*this), 1); 1029 } 1030 1031 _LIBCPP_NO_UNIQUE_ADDRESS _Alloc __alloc_; 1032 union { 1033 _Tp __data_[_Count]; 1034 }; 1035 }; 1036 1037 template <class _Array, class _Alloc, class... _Arg> 1038 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Array> __allocate_shared_bounded_array(const _Alloc& __a, _Arg&&... __arg) { 1039 static_assert(__libcpp_is_bounded_array<_Array>::value); 1040 using _ControlBlock = __bounded_array_control_block<_Array, _Alloc>; 1041 using _ControlBlockAlloc = __allocator_traits_rebind_t<_Alloc, _ControlBlock>; 1042 1043 __allocation_guard<_ControlBlockAlloc> __guard(__a, 1); 1044 _ControlBlock* __control_block = reinterpret_cast<_ControlBlock*>(std::addressof(*__guard.__get())); 1045 std::__construct_at(__control_block, __a, std::forward<_Arg>(__arg)...); 1046 __guard.__release_ptr(); 1047 return shared_ptr<_Array>::__create_with_control_block(__control_block->__get_data(), __control_block); 1048 } 1049 1050 #endif // _LIBCPP_STD_VER >= 17 1051 1052 #if _LIBCPP_STD_VER >= 20 1053 1054 // bounded array variants 1055 template <class _Tp, class _Alloc, __enable_if_t<is_bounded_array<_Tp>::value, int> = 0> 1056 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> allocate_shared(const _Alloc& __a) { 1057 return std::__allocate_shared_bounded_array<_Tp>(__a); 1058 } 1059 1060 template <class _Tp, class _Alloc, __enable_if_t<is_bounded_array<_Tp>::value, int> = 0> 1061 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> allocate_shared(const _Alloc& __a, const remove_extent_t<_Tp>& __u) { 1062 return std::__allocate_shared_bounded_array<_Tp>(__a, __u); 1063 } 1064 1065 template <class _Tp, class _Alloc, __enable_if_t<is_bounded_array<_Tp>::value, int> = 0> 1066 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> allocate_shared_for_overwrite(const _Alloc& __a) { 1067 using _ForOverwriteAllocator = __allocator_traits_rebind_t<_Alloc, __for_overwrite_tag>; 1068 _ForOverwriteAllocator __alloc(__a); 1069 return std::__allocate_shared_bounded_array<_Tp>(__alloc); 1070 } 1071 1072 template <class _Tp, __enable_if_t<is_bounded_array<_Tp>::value, int> = 0> 1073 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> make_shared() { 1074 return std::__allocate_shared_bounded_array<_Tp>(allocator<_Tp>()); 1075 } 1076 1077 template <class _Tp, __enable_if_t<is_bounded_array<_Tp>::value, int> = 0> 1078 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> make_shared(const remove_extent_t<_Tp>& __u) { 1079 return std::__allocate_shared_bounded_array<_Tp>(allocator<_Tp>(), __u); 1080 } 1081 1082 template <class _Tp, __enable_if_t<is_bounded_array<_Tp>::value, int> = 0> 1083 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> make_shared_for_overwrite() { 1084 return std::__allocate_shared_bounded_array<_Tp>(allocator<__for_overwrite_tag>()); 1085 } 1086 1087 // unbounded array variants 1088 template <class _Tp, class _Alloc, __enable_if_t<is_unbounded_array<_Tp>::value, int> = 0> 1089 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> allocate_shared(const _Alloc& __a, size_t __n) { 1090 return std::__allocate_shared_unbounded_array<_Tp>(__a, __n); 1091 } 1092 1093 template <class _Tp, class _Alloc, __enable_if_t<is_unbounded_array<_Tp>::value, int> = 0> 1094 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> allocate_shared(const _Alloc& __a, size_t __n, const remove_extent_t<_Tp>& __u) { 1095 return std::__allocate_shared_unbounded_array<_Tp>(__a, __n, __u); 1096 } 1097 1098 template <class _Tp, class _Alloc, __enable_if_t<is_unbounded_array<_Tp>::value, int> = 0> 1099 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> allocate_shared_for_overwrite(const _Alloc& __a, size_t __n) { 1100 using _ForOverwriteAllocator = __allocator_traits_rebind_t<_Alloc, __for_overwrite_tag>; 1101 _ForOverwriteAllocator __alloc(__a); 1102 return std::__allocate_shared_unbounded_array<_Tp>(__alloc, __n); 1103 } 1104 1105 template <class _Tp, __enable_if_t<is_unbounded_array<_Tp>::value, int> = 0> 1106 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> make_shared(size_t __n) { 1107 return std::__allocate_shared_unbounded_array<_Tp>(allocator<_Tp>(), __n); 1108 } 1109 1110 template <class _Tp, __enable_if_t<is_unbounded_array<_Tp>::value, int> = 0> 1111 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> make_shared(size_t __n, const remove_extent_t<_Tp>& __u) { 1112 return std::__allocate_shared_unbounded_array<_Tp>(allocator<_Tp>(), __n, __u); 1113 } 1114 1115 template <class _Tp, __enable_if_t<is_unbounded_array<_Tp>::value, int> = 0> 1116 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> make_shared_for_overwrite(size_t __n) { 1117 return std::__allocate_shared_unbounded_array<_Tp>(allocator<__for_overwrite_tag>(), __n); 1118 } 1119 1120 #endif // _LIBCPP_STD_VER >= 20 1121 1122 template <class _Tp, class _Up> 1123 inline _LIBCPP_HIDE_FROM_ABI bool operator==(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT { 1124 return __x.get() == __y.get(); 1125 } 1126 1127 #if _LIBCPP_STD_VER <= 17 1128 1129 template <class _Tp, class _Up> 1130 inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT { 1131 return !(__x == __y); 1132 } 1133 1134 template <class _Tp, class _Up> 1135 inline _LIBCPP_HIDE_FROM_ABI bool operator<(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT { 1136 # if _LIBCPP_STD_VER <= 11 1137 typedef typename common_type<_Tp*, _Up*>::type _Vp; 1138 return less<_Vp>()(__x.get(), __y.get()); 1139 # else 1140 return less<>()(__x.get(), __y.get()); 1141 # endif 1142 } 1143 1144 template <class _Tp, class _Up> 1145 inline _LIBCPP_HIDE_FROM_ABI bool operator>(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT { 1146 return __y < __x; 1147 } 1148 1149 template <class _Tp, class _Up> 1150 inline _LIBCPP_HIDE_FROM_ABI bool operator<=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT { 1151 return !(__y < __x); 1152 } 1153 1154 template <class _Tp, class _Up> 1155 inline _LIBCPP_HIDE_FROM_ABI bool operator>=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT { 1156 return !(__x < __y); 1157 } 1158 1159 #endif // _LIBCPP_STD_VER <= 17 1160 1161 #if _LIBCPP_STD_VER >= 20 1162 template <class _Tp, class _Up> 1163 _LIBCPP_HIDE_FROM_ABI strong_ordering operator<=>(shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) noexcept { 1164 return compare_three_way()(__x.get(), __y.get()); 1165 } 1166 #endif 1167 1168 template <class _Tp> 1169 inline _LIBCPP_HIDE_FROM_ABI bool operator==(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT { 1170 return !__x; 1171 } 1172 1173 #if _LIBCPP_STD_VER <= 17 1174 1175 template <class _Tp> 1176 inline _LIBCPP_HIDE_FROM_ABI bool operator==(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT { 1177 return !__x; 1178 } 1179 1180 template <class _Tp> 1181 inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT { 1182 return static_cast<bool>(__x); 1183 } 1184 1185 template <class _Tp> 1186 inline _LIBCPP_HIDE_FROM_ABI bool operator!=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT { 1187 return static_cast<bool>(__x); 1188 } 1189 1190 template <class _Tp> 1191 inline _LIBCPP_HIDE_FROM_ABI bool operator<(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT { 1192 return less<typename shared_ptr<_Tp>::element_type*>()(__x.get(), nullptr); 1193 } 1194 1195 template <class _Tp> 1196 inline _LIBCPP_HIDE_FROM_ABI bool operator<(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT { 1197 return less<typename shared_ptr<_Tp>::element_type*>()(nullptr, __x.get()); 1198 } 1199 1200 template <class _Tp> 1201 inline _LIBCPP_HIDE_FROM_ABI bool operator>(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT { 1202 return nullptr < __x; 1203 } 1204 1205 template <class _Tp> 1206 inline _LIBCPP_HIDE_FROM_ABI bool operator>(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT { 1207 return __x < nullptr; 1208 } 1209 1210 template <class _Tp> 1211 inline _LIBCPP_HIDE_FROM_ABI bool operator<=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT { 1212 return !(nullptr < __x); 1213 } 1214 1215 template <class _Tp> 1216 inline _LIBCPP_HIDE_FROM_ABI bool operator<=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT { 1217 return !(__x < nullptr); 1218 } 1219 1220 template <class _Tp> 1221 inline _LIBCPP_HIDE_FROM_ABI bool operator>=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT { 1222 return !(__x < nullptr); 1223 } 1224 1225 template <class _Tp> 1226 inline _LIBCPP_HIDE_FROM_ABI bool operator>=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT { 1227 return !(nullptr < __x); 1228 } 1229 1230 #endif // _LIBCPP_STD_VER <= 17 1231 1232 #if _LIBCPP_STD_VER >= 20 1233 template <class _Tp> 1234 _LIBCPP_HIDE_FROM_ABI strong_ordering operator<=>(shared_ptr<_Tp> const& __x, nullptr_t) noexcept { 1235 return compare_three_way()(__x.get(), static_cast<typename shared_ptr<_Tp>::element_type*>(nullptr)); 1236 } 1237 #endif 1238 1239 template <class _Tp> 1240 inline _LIBCPP_HIDE_FROM_ABI void swap(shared_ptr<_Tp>& __x, shared_ptr<_Tp>& __y) _NOEXCEPT { 1241 __x.swap(__y); 1242 } 1243 1244 template <class _Tp, class _Up> 1245 inline _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> static_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT { 1246 return shared_ptr<_Tp>(__r, static_cast< typename shared_ptr<_Tp>::element_type*>(__r.get())); 1247 } 1248 1249 // LWG-2996 1250 // We don't backport because it is an evolutionary change. 1251 #if _LIBCPP_STD_VER >= 20 1252 template <class _Tp, class _Up> 1253 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> static_pointer_cast(shared_ptr<_Up>&& __r) noexcept { 1254 return shared_ptr<_Tp>(std::move(__r), static_cast<typename shared_ptr<_Tp>::element_type*>(__r.get())); 1255 } 1256 #endif 1257 1258 template <class _Tp, class _Up> 1259 inline _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> dynamic_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT { 1260 typedef typename shared_ptr<_Tp>::element_type _ET; 1261 _ET* __p = dynamic_cast<_ET*>(__r.get()); 1262 return __p ? shared_ptr<_Tp>(__r, __p) : shared_ptr<_Tp>(); 1263 } 1264 1265 // LWG-2996 1266 // We don't backport because it is an evolutionary change. 1267 #if _LIBCPP_STD_VER >= 20 1268 template <class _Tp, class _Up> 1269 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> dynamic_pointer_cast(shared_ptr<_Up>&& __r) noexcept { 1270 auto* __p = dynamic_cast<typename shared_ptr<_Tp>::element_type*>(__r.get()); 1271 return __p ? shared_ptr<_Tp>(std::move(__r), __p) : shared_ptr<_Tp>(); 1272 } 1273 #endif 1274 1275 template <class _Tp, class _Up> 1276 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> const_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT { 1277 typedef typename shared_ptr<_Tp>::element_type _RTp; 1278 return shared_ptr<_Tp>(__r, const_cast<_RTp*>(__r.get())); 1279 } 1280 1281 // LWG-2996 1282 // We don't backport because it is an evolutionary change. 1283 #if _LIBCPP_STD_VER >= 20 1284 template <class _Tp, class _Up> 1285 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> const_pointer_cast(shared_ptr<_Up>&& __r) noexcept { 1286 return shared_ptr<_Tp>(std::move(__r), const_cast<typename shared_ptr<_Tp>::element_type*>(__r.get())); 1287 } 1288 #endif 1289 1290 template <class _Tp, class _Up> 1291 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> reinterpret_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT { 1292 return shared_ptr<_Tp>(__r, reinterpret_cast< typename shared_ptr<_Tp>::element_type*>(__r.get())); 1293 } 1294 1295 // LWG-2996 1296 // We don't backport because it is an evolutionary change. 1297 #if _LIBCPP_STD_VER >= 20 1298 template <class _Tp, class _Up> 1299 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> reinterpret_pointer_cast(shared_ptr<_Up>&& __r) noexcept { 1300 return shared_ptr<_Tp>(std::move(__r), reinterpret_cast<typename shared_ptr<_Tp>::element_type*>(__r.get())); 1301 } 1302 #endif 1303 1304 #ifndef _LIBCPP_HAS_NO_RTTI 1305 1306 template <class _Dp, class _Tp> 1307 inline _LIBCPP_HIDE_FROM_ABI _Dp* get_deleter(const shared_ptr<_Tp>& __p) _NOEXCEPT { 1308 return __p.template __get_deleter<_Dp>(); 1309 } 1310 1311 #endif // _LIBCPP_HAS_NO_RTTI 1312 1313 template <class _Tp> 1314 class _LIBCPP_SHARED_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS weak_ptr { 1315 public: 1316 #if _LIBCPP_STD_VER >= 17 1317 typedef remove_extent_t<_Tp> element_type; 1318 #else 1319 typedef _Tp element_type; 1320 #endif 1321 1322 // A weak_ptr contains only two raw pointers which point to the heap and move constructing already doesn't require 1323 // any bookkeeping, so it's always trivially relocatable. 1324 using __trivially_relocatable = weak_ptr; 1325 1326 private: 1327 element_type* __ptr_; 1328 __shared_weak_count* __cntrl_; 1329 1330 public: 1331 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR weak_ptr() _NOEXCEPT; 1332 1333 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0> 1334 _LIBCPP_HIDE_FROM_ABI weak_ptr(shared_ptr<_Yp> const& __r) _NOEXCEPT; 1335 1336 _LIBCPP_HIDE_FROM_ABI weak_ptr(weak_ptr const& __r) _NOEXCEPT; 1337 1338 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0> 1339 _LIBCPP_HIDE_FROM_ABI weak_ptr(weak_ptr<_Yp> const& __r) _NOEXCEPT; 1340 1341 _LIBCPP_HIDE_FROM_ABI weak_ptr(weak_ptr&& __r) _NOEXCEPT; 1342 1343 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0> 1344 _LIBCPP_HIDE_FROM_ABI weak_ptr(weak_ptr<_Yp>&& __r) _NOEXCEPT; 1345 1346 _LIBCPP_HIDE_FROM_ABI ~weak_ptr(); 1347 1348 _LIBCPP_HIDE_FROM_ABI weak_ptr& operator=(weak_ptr const& __r) _NOEXCEPT; 1349 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0> 1350 _LIBCPP_HIDE_FROM_ABI weak_ptr& operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT; 1351 1352 _LIBCPP_HIDE_FROM_ABI weak_ptr& operator=(weak_ptr&& __r) _NOEXCEPT; 1353 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0> 1354 _LIBCPP_HIDE_FROM_ABI weak_ptr& operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT; 1355 1356 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0> 1357 _LIBCPP_HIDE_FROM_ABI weak_ptr& operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT; 1358 1359 _LIBCPP_HIDE_FROM_ABI void swap(weak_ptr& __r) _NOEXCEPT; 1360 _LIBCPP_HIDE_FROM_ABI void reset() _NOEXCEPT; 1361 1362 _LIBCPP_HIDE_FROM_ABI long use_count() const _NOEXCEPT { return __cntrl_ ? __cntrl_->use_count() : 0; } 1363 _LIBCPP_HIDE_FROM_ABI bool expired() const _NOEXCEPT { return __cntrl_ == nullptr || __cntrl_->use_count() == 0; } 1364 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> lock() const _NOEXCEPT; 1365 template <class _Up> 1366 _LIBCPP_HIDE_FROM_ABI bool owner_before(const shared_ptr<_Up>& __r) const _NOEXCEPT { 1367 return __cntrl_ < __r.__cntrl_; 1368 } 1369 template <class _Up> 1370 _LIBCPP_HIDE_FROM_ABI bool owner_before(const weak_ptr<_Up>& __r) const _NOEXCEPT { 1371 return __cntrl_ < __r.__cntrl_; 1372 } 1373 1374 template <class _Up> 1375 friend class _LIBCPP_TEMPLATE_VIS weak_ptr; 1376 template <class _Up> 1377 friend class _LIBCPP_TEMPLATE_VIS shared_ptr; 1378 }; 1379 1380 #if _LIBCPP_STD_VER >= 17 1381 template <class _Tp> 1382 weak_ptr(shared_ptr<_Tp>) -> weak_ptr<_Tp>; 1383 #endif 1384 1385 template <class _Tp> 1386 inline _LIBCPP_CONSTEXPR weak_ptr<_Tp>::weak_ptr() _NOEXCEPT : __ptr_(nullptr), __cntrl_(nullptr) {} 1387 1388 template <class _Tp> 1389 inline weak_ptr<_Tp>::weak_ptr(weak_ptr const& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) { 1390 if (__cntrl_) 1391 __cntrl_->__add_weak(); 1392 } 1393 1394 template <class _Tp> 1395 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> > 1396 inline weak_ptr<_Tp>::weak_ptr(shared_ptr<_Yp> const& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) { 1397 if (__cntrl_) 1398 __cntrl_->__add_weak(); 1399 } 1400 1401 template <class _Tp> 1402 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> > 1403 inline weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp> const& __r) _NOEXCEPT : __ptr_(nullptr), __cntrl_(nullptr) { 1404 shared_ptr<_Yp> __s = __r.lock(); 1405 *this = weak_ptr<_Tp>(__s); 1406 } 1407 1408 template <class _Tp> 1409 inline weak_ptr<_Tp>::weak_ptr(weak_ptr&& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) { 1410 __r.__ptr_ = nullptr; 1411 __r.__cntrl_ = nullptr; 1412 } 1413 1414 template <class _Tp> 1415 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> > 1416 inline weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp>&& __r) _NOEXCEPT : __ptr_(nullptr), __cntrl_(nullptr) { 1417 shared_ptr<_Yp> __s = __r.lock(); 1418 *this = weak_ptr<_Tp>(__s); 1419 __r.reset(); 1420 } 1421 1422 template <class _Tp> 1423 weak_ptr<_Tp>::~weak_ptr() { 1424 if (__cntrl_) 1425 __cntrl_->__release_weak(); 1426 } 1427 1428 template <class _Tp> 1429 inline weak_ptr<_Tp>& weak_ptr<_Tp>::operator=(weak_ptr const& __r) _NOEXCEPT { 1430 weak_ptr(__r).swap(*this); 1431 return *this; 1432 } 1433 1434 template <class _Tp> 1435 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> > 1436 inline weak_ptr<_Tp>& weak_ptr<_Tp>::operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT { 1437 weak_ptr(__r).swap(*this); 1438 return *this; 1439 } 1440 1441 template <class _Tp> 1442 inline weak_ptr<_Tp>& weak_ptr<_Tp>::operator=(weak_ptr&& __r) _NOEXCEPT { 1443 weak_ptr(std::move(__r)).swap(*this); 1444 return *this; 1445 } 1446 1447 template <class _Tp> 1448 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> > 1449 inline weak_ptr<_Tp>& weak_ptr<_Tp>::operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT { 1450 weak_ptr(std::move(__r)).swap(*this); 1451 return *this; 1452 } 1453 1454 template <class _Tp> 1455 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> > 1456 inline weak_ptr<_Tp>& weak_ptr<_Tp>::operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT { 1457 weak_ptr(__r).swap(*this); 1458 return *this; 1459 } 1460 1461 template <class _Tp> 1462 inline void weak_ptr<_Tp>::swap(weak_ptr& __r) _NOEXCEPT { 1463 std::swap(__ptr_, __r.__ptr_); 1464 std::swap(__cntrl_, __r.__cntrl_); 1465 } 1466 1467 template <class _Tp> 1468 inline _LIBCPP_HIDE_FROM_ABI void swap(weak_ptr<_Tp>& __x, weak_ptr<_Tp>& __y) _NOEXCEPT { 1469 __x.swap(__y); 1470 } 1471 1472 template <class _Tp> 1473 inline void weak_ptr<_Tp>::reset() _NOEXCEPT { 1474 weak_ptr().swap(*this); 1475 } 1476 1477 template <class _Tp> 1478 shared_ptr<_Tp> weak_ptr<_Tp>::lock() const _NOEXCEPT { 1479 shared_ptr<_Tp> __r; 1480 __r.__cntrl_ = __cntrl_ ? __cntrl_->lock() : __cntrl_; 1481 if (__r.__cntrl_) 1482 __r.__ptr_ = __ptr_; 1483 return __r; 1484 } 1485 1486 #if _LIBCPP_STD_VER >= 17 1487 template <class _Tp = void> 1488 struct owner_less; 1489 #else 1490 template <class _Tp> 1491 struct owner_less; 1492 #endif 1493 1494 template <class _Tp> 1495 struct _LIBCPP_TEMPLATE_VIS owner_less<shared_ptr<_Tp> > : __binary_function<shared_ptr<_Tp>, shared_ptr<_Tp>, bool> { 1496 _LIBCPP_HIDE_FROM_ABI bool operator()(shared_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT { 1497 return __x.owner_before(__y); 1498 } 1499 _LIBCPP_HIDE_FROM_ABI bool operator()(shared_ptr<_Tp> const& __x, weak_ptr<_Tp> const& __y) const _NOEXCEPT { 1500 return __x.owner_before(__y); 1501 } 1502 _LIBCPP_HIDE_FROM_ABI bool operator()(weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT { 1503 return __x.owner_before(__y); 1504 } 1505 }; 1506 1507 template <class _Tp> 1508 struct _LIBCPP_TEMPLATE_VIS owner_less<weak_ptr<_Tp> > : __binary_function<weak_ptr<_Tp>, weak_ptr<_Tp>, bool> { 1509 _LIBCPP_HIDE_FROM_ABI bool operator()(weak_ptr<_Tp> const& __x, weak_ptr<_Tp> const& __y) const _NOEXCEPT { 1510 return __x.owner_before(__y); 1511 } 1512 _LIBCPP_HIDE_FROM_ABI bool operator()(shared_ptr<_Tp> const& __x, weak_ptr<_Tp> const& __y) const _NOEXCEPT { 1513 return __x.owner_before(__y); 1514 } 1515 _LIBCPP_HIDE_FROM_ABI bool operator()(weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT { 1516 return __x.owner_before(__y); 1517 } 1518 }; 1519 1520 #if _LIBCPP_STD_VER >= 17 1521 template <> 1522 struct _LIBCPP_TEMPLATE_VIS owner_less<void> { 1523 template <class _Tp, class _Up> 1524 _LIBCPP_HIDE_FROM_ABI bool operator()(shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT { 1525 return __x.owner_before(__y); 1526 } 1527 template <class _Tp, class _Up> 1528 _LIBCPP_HIDE_FROM_ABI bool operator()(shared_ptr<_Tp> const& __x, weak_ptr<_Up> const& __y) const _NOEXCEPT { 1529 return __x.owner_before(__y); 1530 } 1531 template <class _Tp, class _Up> 1532 _LIBCPP_HIDE_FROM_ABI bool operator()(weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT { 1533 return __x.owner_before(__y); 1534 } 1535 template <class _Tp, class _Up> 1536 _LIBCPP_HIDE_FROM_ABI bool operator()(weak_ptr<_Tp> const& __x, weak_ptr<_Up> const& __y) const _NOEXCEPT { 1537 return __x.owner_before(__y); 1538 } 1539 typedef void is_transparent; 1540 }; 1541 #endif 1542 1543 template <class _Tp> 1544 class _LIBCPP_TEMPLATE_VIS enable_shared_from_this { 1545 mutable weak_ptr<_Tp> __weak_this_; 1546 1547 protected: 1548 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR enable_shared_from_this() _NOEXCEPT {} 1549 _LIBCPP_HIDE_FROM_ABI enable_shared_from_this(enable_shared_from_this const&) _NOEXCEPT {} 1550 _LIBCPP_HIDE_FROM_ABI enable_shared_from_this& operator=(enable_shared_from_this const&) _NOEXCEPT { return *this; } 1551 _LIBCPP_HIDE_FROM_ABI ~enable_shared_from_this() {} 1552 1553 public: 1554 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> shared_from_this() { return shared_ptr<_Tp>(__weak_this_); } 1555 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp const> shared_from_this() const { return shared_ptr<const _Tp>(__weak_this_); } 1556 1557 #if _LIBCPP_STD_VER >= 17 1558 _LIBCPP_HIDE_FROM_ABI weak_ptr<_Tp> weak_from_this() _NOEXCEPT { return __weak_this_; } 1559 1560 _LIBCPP_HIDE_FROM_ABI weak_ptr<const _Tp> weak_from_this() const _NOEXCEPT { return __weak_this_; } 1561 #endif // _LIBCPP_STD_VER >= 17 1562 1563 template <class _Up> 1564 friend class shared_ptr; 1565 }; 1566 1567 template <class _Tp> 1568 struct _LIBCPP_TEMPLATE_VIS hash; 1569 1570 template <class _Tp> 1571 struct _LIBCPP_TEMPLATE_VIS hash<shared_ptr<_Tp> > { 1572 #if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_BINDER_TYPEDEFS) 1573 _LIBCPP_DEPRECATED_IN_CXX17 typedef shared_ptr<_Tp> argument_type; 1574 _LIBCPP_DEPRECATED_IN_CXX17 typedef size_t result_type; 1575 #endif 1576 1577 _LIBCPP_HIDE_FROM_ABI size_t operator()(const shared_ptr<_Tp>& __ptr) const _NOEXCEPT { 1578 return hash<typename shared_ptr<_Tp>::element_type*>()(__ptr.get()); 1579 } 1580 }; 1581 1582 template <class _CharT, class _Traits, class _Yp> 1583 inline _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>& 1584 operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p); 1585 1586 #if !defined(_LIBCPP_HAS_NO_THREADS) 1587 1588 class _LIBCPP_EXPORTED_FROM_ABI __sp_mut { 1589 void* __lx_; 1590 1591 public: 1592 void lock() _NOEXCEPT; 1593 void unlock() _NOEXCEPT; 1594 1595 private: 1596 _LIBCPP_CONSTEXPR __sp_mut(void*) _NOEXCEPT; 1597 __sp_mut(const __sp_mut&); 1598 __sp_mut& operator=(const __sp_mut&); 1599 1600 friend _LIBCPP_EXPORTED_FROM_ABI __sp_mut& __get_sp_mut(const void*); 1601 }; 1602 1603 _LIBCPP_EXPORTED_FROM_ABI __sp_mut& __get_sp_mut(const void*); 1604 1605 template <class _Tp> 1606 inline _LIBCPP_HIDE_FROM_ABI bool atomic_is_lock_free(const shared_ptr<_Tp>*) { 1607 return false; 1608 } 1609 1610 template <class _Tp> 1611 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> atomic_load(const shared_ptr<_Tp>* __p) { 1612 __sp_mut& __m = std::__get_sp_mut(__p); 1613 __m.lock(); 1614 shared_ptr<_Tp> __q = *__p; 1615 __m.unlock(); 1616 return __q; 1617 } 1618 1619 template <class _Tp> 1620 inline _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> atomic_load_explicit(const shared_ptr<_Tp>* __p, memory_order) { 1621 return std::atomic_load(__p); 1622 } 1623 1624 template <class _Tp> 1625 _LIBCPP_HIDE_FROM_ABI void atomic_store(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r) { 1626 __sp_mut& __m = std::__get_sp_mut(__p); 1627 __m.lock(); 1628 __p->swap(__r); 1629 __m.unlock(); 1630 } 1631 1632 template <class _Tp> 1633 inline _LIBCPP_HIDE_FROM_ABI void atomic_store_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order) { 1634 std::atomic_store(__p, __r); 1635 } 1636 1637 template <class _Tp> 1638 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> atomic_exchange(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r) { 1639 __sp_mut& __m = std::__get_sp_mut(__p); 1640 __m.lock(); 1641 __p->swap(__r); 1642 __m.unlock(); 1643 return __r; 1644 } 1645 1646 template <class _Tp> 1647 inline _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> 1648 atomic_exchange_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order) { 1649 return std::atomic_exchange(__p, __r); 1650 } 1651 1652 template <class _Tp> 1653 _LIBCPP_HIDE_FROM_ABI bool 1654 atomic_compare_exchange_strong(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w) { 1655 shared_ptr<_Tp> __temp; 1656 __sp_mut& __m = std::__get_sp_mut(__p); 1657 __m.lock(); 1658 if (__p->__owner_equivalent(*__v)) { 1659 std::swap(__temp, *__p); 1660 *__p = __w; 1661 __m.unlock(); 1662 return true; 1663 } 1664 std::swap(__temp, *__v); 1665 *__v = *__p; 1666 __m.unlock(); 1667 return false; 1668 } 1669 1670 template <class _Tp> 1671 inline _LIBCPP_HIDE_FROM_ABI bool 1672 atomic_compare_exchange_weak(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w) { 1673 return std::atomic_compare_exchange_strong(__p, __v, __w); 1674 } 1675 1676 template <class _Tp> 1677 inline _LIBCPP_HIDE_FROM_ABI bool atomic_compare_exchange_strong_explicit( 1678 shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w, memory_order, memory_order) { 1679 return std::atomic_compare_exchange_strong(__p, __v, __w); 1680 } 1681 1682 template <class _Tp> 1683 inline _LIBCPP_HIDE_FROM_ABI bool atomic_compare_exchange_weak_explicit( 1684 shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w, memory_order, memory_order) { 1685 return std::atomic_compare_exchange_weak(__p, __v, __w); 1686 } 1687 1688 #endif // !defined(_LIBCPP_HAS_NO_THREADS) 1689 1690 _LIBCPP_END_NAMESPACE_STD 1691 1692 _LIBCPP_POP_MACROS 1693 1694 #endif // _LIBCPP___MEMORY_SHARED_PTR_H 1695