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 <__availability> 14 #include <__compare/compare_three_way.h> 15 #include <__compare/ordering.h> 16 #include <__config> 17 #include <__functional/binary_function.h> 18 #include <__functional/operations.h> 19 #include <__functional/reference_wrapper.h> 20 #include <__iterator/access.h> 21 #include <__memory/addressof.h> 22 #include <__memory/allocation_guard.h> 23 #include <__memory/allocator.h> 24 #include <__memory/allocator_destructor.h> 25 #include <__memory/allocator_traits.h> 26 #include <__memory/auto_ptr.h> 27 #include <__memory/compressed_pair.h> 28 #include <__memory/construct_at.h> 29 #include <__memory/pointer_traits.h> 30 #include <__memory/uninitialized_algorithms.h> 31 #include <__memory/unique_ptr.h> 32 #include <__type_traits/add_lvalue_reference.h> 33 #include <__type_traits/conditional.h> 34 #include <__type_traits/conjunction.h> 35 #include <__type_traits/disjunction.h> 36 #include <__type_traits/is_array.h> 37 #include <__type_traits/is_bounded_array.h> 38 #include <__type_traits/is_convertible.h> 39 #include <__type_traits/is_move_constructible.h> 40 #include <__type_traits/is_reference.h> 41 #include <__type_traits/is_unbounded_array.h> 42 #include <__type_traits/nat.h> 43 #include <__type_traits/negation.h> 44 #include <__type_traits/remove_extent.h> 45 #include <__type_traits/remove_reference.h> 46 #include <__utility/declval.h> 47 #include <__utility/forward.h> 48 #include <__utility/move.h> 49 #include <__utility/swap.h> 50 #include <__verbose_abort> 51 #include <cstddef> 52 #include <iosfwd> 53 #include <new> 54 #include <stdexcept> 55 #include <typeinfo> 56 #if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER) 57 # include <__atomic/memory_order.h> 58 #endif 59 60 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 61 # pragma GCC system_header 62 #endif 63 64 _LIBCPP_BEGIN_NAMESPACE_STD 65 66 // NOTE: Relaxed and acq/rel atomics (for increment and decrement respectively) 67 // should be sufficient for thread safety. 68 // See https://llvm.org/PR22803 69 #if defined(__clang__) && __has_builtin(__atomic_add_fetch) \ 70 && defined(__ATOMIC_RELAXED) \ 71 && 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_INLINE_VISIBILITY 79 _ValueType __libcpp_relaxed_load(_ValueType const* __value) { 80 #if !defined(_LIBCPP_HAS_NO_THREADS) && \ 81 defined(__ATOMIC_RELAXED) && \ 82 (__has_builtin(__atomic_load_n) || defined(_LIBCPP_COMPILER_GCC)) 83 return __atomic_load_n(__value, __ATOMIC_RELAXED); 84 #else 85 return *__value; 86 #endif 87 } 88 89 template <class _ValueType> 90 inline _LIBCPP_INLINE_VISIBILITY 91 _ValueType __libcpp_acquire_load(_ValueType const* __value) { 92 #if !defined(_LIBCPP_HAS_NO_THREADS) && \ 93 defined(__ATOMIC_ACQUIRE) && \ 94 (__has_builtin(__atomic_load_n) || defined(_LIBCPP_COMPILER_GCC)) 95 return __atomic_load_n(__value, __ATOMIC_ACQUIRE); 96 #else 97 return *__value; 98 #endif 99 } 100 101 template <class _Tp> 102 inline _LIBCPP_INLINE_VISIBILITY _Tp 103 __libcpp_atomic_refcount_increment(_Tp& __t) _NOEXCEPT 104 { 105 #if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS) 106 return __atomic_add_fetch(&__t, 1, __ATOMIC_RELAXED); 107 #else 108 return __t += 1; 109 #endif 110 } 111 112 template <class _Tp> 113 inline _LIBCPP_INLINE_VISIBILITY _Tp 114 __libcpp_atomic_refcount_decrement(_Tp& __t) _NOEXCEPT 115 { 116 #if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS) 117 return __atomic_add_fetch(&__t, -1, __ATOMIC_ACQ_REL); 118 #else 119 return __t -= 1; 120 #endif 121 } 122 123 class _LIBCPP_EXPORTED_FROM_ABI bad_weak_ptr 124 : public std::exception 125 { 126 public: 127 _LIBCPP_HIDE_FROM_ABI bad_weak_ptr() _NOEXCEPT = default; 128 _LIBCPP_HIDE_FROM_ABI bad_weak_ptr(const bad_weak_ptr&) _NOEXCEPT = default; 129 ~bad_weak_ptr() _NOEXCEPT override; 130 const char* what() const _NOEXCEPT override; 131 }; 132 133 _LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY 134 void __throw_bad_weak_ptr() 135 { 136 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 137 throw bad_weak_ptr(); 138 #else 139 _LIBCPP_VERBOSE_ABORT("bad_weak_ptr was thrown in -fno-exceptions mode"); 140 #endif 141 } 142 143 template<class _Tp> class _LIBCPP_TEMPLATE_VIS weak_ptr; 144 145 class _LIBCPP_EXPORTED_FROM_ABI __shared_count 146 { 147 __shared_count(const __shared_count&); 148 __shared_count& operator=(const __shared_count&); 149 150 protected: 151 long __shared_owners_; 152 virtual ~__shared_count(); 153 private: 154 virtual void __on_zero_shared() _NOEXCEPT = 0; 155 156 public: 157 _LIBCPP_INLINE_VISIBILITY 158 explicit __shared_count(long __refs = 0) _NOEXCEPT 159 : __shared_owners_(__refs) {} 160 161 #if defined(_LIBCPP_SHARED_PTR_DEFINE_LEGACY_INLINE_FUNCTIONS) 162 void __add_shared() noexcept; 163 bool __release_shared() noexcept; 164 #else 165 _LIBCPP_INLINE_VISIBILITY 166 void __add_shared() _NOEXCEPT { 167 __libcpp_atomic_refcount_increment(__shared_owners_); 168 } 169 _LIBCPP_INLINE_VISIBILITY 170 bool __release_shared() _NOEXCEPT { 171 if (__libcpp_atomic_refcount_decrement(__shared_owners_) == -1) { 172 __on_zero_shared(); 173 return true; 174 } 175 return false; 176 } 177 #endif 178 _LIBCPP_INLINE_VISIBILITY 179 long use_count() const _NOEXCEPT { 180 return __libcpp_relaxed_load(&__shared_owners_) + 1; 181 } 182 }; 183 184 class _LIBCPP_EXPORTED_FROM_ABI __shared_weak_count 185 : private __shared_count 186 { 187 long __shared_weak_owners_; 188 189 public: 190 _LIBCPP_INLINE_VISIBILITY 191 explicit __shared_weak_count(long __refs = 0) _NOEXCEPT 192 : __shared_count(__refs), 193 __shared_weak_owners_(__refs) {} 194 protected: 195 ~__shared_weak_count() override; 196 197 public: 198 #if defined(_LIBCPP_SHARED_PTR_DEFINE_LEGACY_INLINE_FUNCTIONS) 199 void __add_shared() noexcept; 200 void __add_weak() noexcept; 201 void __release_shared() noexcept; 202 #else 203 _LIBCPP_INLINE_VISIBILITY 204 void __add_shared() _NOEXCEPT { 205 __shared_count::__add_shared(); 206 } 207 _LIBCPP_INLINE_VISIBILITY 208 void __add_weak() _NOEXCEPT { 209 __libcpp_atomic_refcount_increment(__shared_weak_owners_); 210 } 211 _LIBCPP_INLINE_VISIBILITY 212 void __release_shared() _NOEXCEPT { 213 if (__shared_count::__release_shared()) 214 __release_weak(); 215 } 216 #endif 217 void __release_weak() _NOEXCEPT; 218 _LIBCPP_INLINE_VISIBILITY 219 long use_count() const _NOEXCEPT {return __shared_count::use_count();} 220 __shared_weak_count* lock() _NOEXCEPT; 221 222 virtual const void* __get_deleter(const type_info&) const _NOEXCEPT; 223 private: 224 virtual void __on_zero_shared_weak() _NOEXCEPT = 0; 225 }; 226 227 template <class _Tp, class _Dp, class _Alloc> 228 class __shared_ptr_pointer 229 : public __shared_weak_count 230 { 231 __compressed_pair<__compressed_pair<_Tp, _Dp>, _Alloc> __data_; 232 public: 233 _LIBCPP_INLINE_VISIBILITY 234 __shared_ptr_pointer(_Tp __p, _Dp __d, _Alloc __a) 235 : __data_(__compressed_pair<_Tp, _Dp>(__p, _VSTD::move(__d)), _VSTD::move(__a)) {} 236 237 #ifndef _LIBCPP_HAS_NO_RTTI 238 _LIBCPP_HIDE_FROM_ABI_VIRTUAL const void* __get_deleter(const type_info&) const _NOEXCEPT override; 239 #endif 240 241 private: 242 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override; 243 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared_weak() _NOEXCEPT override; 244 }; 245 246 #ifndef _LIBCPP_HAS_NO_RTTI 247 248 template <class _Tp, class _Dp, class _Alloc> 249 const void* 250 __shared_ptr_pointer<_Tp, _Dp, _Alloc>::__get_deleter(const type_info& __t) const _NOEXCEPT 251 { 252 return __t == typeid(_Dp) ? _VSTD::addressof(__data_.first().second()) : nullptr; 253 } 254 255 #endif // _LIBCPP_HAS_NO_RTTI 256 257 template <class _Tp, class _Dp, class _Alloc> 258 void 259 __shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared() _NOEXCEPT 260 { 261 __data_.first().second()(__data_.first().first()); 262 __data_.first().second().~_Dp(); 263 } 264 265 template <class _Tp, class _Dp, class _Alloc> 266 void 267 __shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT 268 { 269 typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_pointer>::type _Al; 270 typedef allocator_traits<_Al> _ATraits; 271 typedef pointer_traits<typename _ATraits::pointer> _PTraits; 272 273 _Al __a(__data_.second()); 274 __data_.second().~_Alloc(); 275 __a.deallocate(_PTraits::pointer_to(*this), 1); 276 } 277 278 // This tag is used to instantiate an allocator type. The various shared_ptr control blocks 279 // detect that the allocator has been instantiated for this type and perform alternative 280 // initialization/destruction based on that. 281 struct __for_overwrite_tag {}; 282 283 template <class _Tp, class _Alloc> 284 struct __shared_ptr_emplace 285 : __shared_weak_count 286 { 287 template<class ..._Args> 288 _LIBCPP_HIDE_FROM_ABI 289 explicit __shared_ptr_emplace(_Alloc __a, _Args&& ...__args) 290 : __storage_(_VSTD::move(__a)) 291 { 292 #if _LIBCPP_STD_VER >= 20 293 if constexpr (is_same_v<typename _Alloc::value_type, __for_overwrite_tag>) { 294 static_assert(sizeof...(_Args) == 0, "No argument should be provided to the control block when using _for_overwrite"); 295 ::new ((void*)__get_elem()) _Tp; 296 } else { 297 using _TpAlloc = typename __allocator_traits_rebind<_Alloc, _Tp>::type; 298 _TpAlloc __tmp(*__get_alloc()); 299 allocator_traits<_TpAlloc>::construct(__tmp, __get_elem(), _VSTD::forward<_Args>(__args)...); 300 } 301 #else 302 ::new ((void*)__get_elem()) _Tp(_VSTD::forward<_Args>(__args)...); 303 #endif 304 } 305 306 _LIBCPP_HIDE_FROM_ABI 307 _Alloc* __get_alloc() _NOEXCEPT { return __storage_.__get_alloc(); } 308 309 _LIBCPP_HIDE_FROM_ABI 310 _Tp* __get_elem() _NOEXCEPT { return __storage_.__get_elem(); } 311 312 private: 313 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override { 314 #if _LIBCPP_STD_VER >= 20 315 if constexpr (is_same_v<typename _Alloc::value_type, __for_overwrite_tag>) { 316 __get_elem()->~_Tp(); 317 } else { 318 using _TpAlloc = typename __allocator_traits_rebind<_Alloc, _Tp>::type; 319 _TpAlloc __tmp(*__get_alloc()); 320 allocator_traits<_TpAlloc>::destroy(__tmp, __get_elem()); 321 } 322 #else 323 __get_elem()->~_Tp(); 324 #endif 325 } 326 327 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared_weak() _NOEXCEPT override { 328 using _ControlBlockAlloc = typename __allocator_traits_rebind<_Alloc, __shared_ptr_emplace>::type; 329 using _ControlBlockPointer = typename allocator_traits<_ControlBlockAlloc>::pointer; 330 _ControlBlockAlloc __tmp(*__get_alloc()); 331 __storage_.~_Storage(); 332 allocator_traits<_ControlBlockAlloc>::deallocate(__tmp, 333 pointer_traits<_ControlBlockPointer>::pointer_to(*this), 1); 334 } 335 336 // This class implements the control block for non-array shared pointers created 337 // through `std::allocate_shared` and `std::make_shared`. 338 // 339 // In previous versions of the library, we used a compressed pair to store 340 // both the _Alloc and the _Tp. This implies using EBO, which is incompatible 341 // with Allocator construction for _Tp. To allow implementing P0674 in C++20, 342 // we now use a properly aligned char buffer while making sure that we maintain 343 // the same layout that we had when we used a compressed pair. 344 using _CompressedPair = __compressed_pair<_Alloc, _Tp>; 345 struct _ALIGNAS_TYPE(_CompressedPair) _Storage { 346 char __blob_[sizeof(_CompressedPair)]; 347 348 _LIBCPP_HIDE_FROM_ABI explicit _Storage(_Alloc&& __a) { 349 ::new ((void*)__get_alloc()) _Alloc(_VSTD::move(__a)); 350 } 351 _LIBCPP_HIDE_FROM_ABI ~_Storage() { 352 __get_alloc()->~_Alloc(); 353 } 354 _LIBCPP_HIDE_FROM_ABI _Alloc* __get_alloc() _NOEXCEPT { 355 _CompressedPair *__as_pair = reinterpret_cast<_CompressedPair*>(__blob_); 356 typename _CompressedPair::_Base1* __first = _CompressedPair::__get_first_base(__as_pair); 357 _Alloc *__alloc = reinterpret_cast<_Alloc*>(__first); 358 return __alloc; 359 } 360 _LIBCPP_HIDE_FROM_ABI _LIBCPP_NO_CFI _Tp* __get_elem() _NOEXCEPT { 361 _CompressedPair *__as_pair = reinterpret_cast<_CompressedPair*>(__blob_); 362 typename _CompressedPair::_Base2* __second = _CompressedPair::__get_second_base(__as_pair); 363 _Tp *__elem = reinterpret_cast<_Tp*>(__second); 364 return __elem; 365 } 366 }; 367 368 static_assert(_LIBCPP_ALIGNOF(_Storage) == _LIBCPP_ALIGNOF(_CompressedPair), ""); 369 static_assert(sizeof(_Storage) == sizeof(_CompressedPair), ""); 370 _Storage __storage_; 371 }; 372 373 struct __shared_ptr_dummy_rebind_allocator_type; 374 template <> 375 class _LIBCPP_TEMPLATE_VIS allocator<__shared_ptr_dummy_rebind_allocator_type> 376 { 377 public: 378 template <class _Other> 379 struct rebind 380 { 381 typedef allocator<_Other> other; 382 }; 383 }; 384 385 template<class _Tp> class _LIBCPP_TEMPLATE_VIS enable_shared_from_this; 386 387 // http://eel.is/c++draft/util.sharedptr#util.smartptr.shared.general-6 388 // A pointer type Y* is said to be compatible with a pointer type T* 389 // when either Y* is convertible to T* or Y is U[N] and T is cv U[]. 390 #if _LIBCPP_STD_VER >= 17 391 template <class _Yp, class _Tp> 392 struct __bounded_convertible_to_unbounded : false_type {}; 393 394 template <class _Up, std::size_t _Np, class _Tp> 395 struct __bounded_convertible_to_unbounded<_Up[_Np], _Tp> 396 : is_same<__remove_cv_t<_Tp>, _Up[]> {}; 397 398 template <class _Yp, class _Tp> 399 struct __compatible_with 400 : _Or< 401 is_convertible<_Yp*, _Tp*>, 402 __bounded_convertible_to_unbounded<_Yp, _Tp> 403 > {}; 404 #else 405 template <class _Yp, class _Tp> 406 struct __compatible_with 407 : is_convertible<_Yp*, _Tp*> {}; 408 #endif // _LIBCPP_STD_VER >= 17 409 410 // Constructors that take raw pointers have a different set of "compatible" constraints 411 // http://eel.is/c++draft/util.sharedptr#util.smartptr.shared.const-9.1 412 // - If T is an array type, then either T is U[N] and Y(*)[N] is convertible to T*, 413 // or T is U[] and Y(*)[] is convertible to T*. 414 // - If T is not an array type, then Y* is convertible to T*. 415 #if _LIBCPP_STD_VER >= 17 416 template <class _Yp, class _Tp, class = void> 417 struct __raw_pointer_compatible_with : _And< 418 _Not<is_array<_Tp>>, 419 is_convertible<_Yp*, _Tp*> 420 > {}; 421 422 template <class _Yp, class _Up, std::size_t _Np> 423 struct __raw_pointer_compatible_with<_Yp, _Up[_Np], __enable_if_t< 424 is_convertible<_Yp(*)[_Np], _Up(*)[_Np]>::value> > 425 : true_type {}; 426 427 template <class _Yp, class _Up> 428 struct __raw_pointer_compatible_with<_Yp, _Up[], __enable_if_t< 429 is_convertible<_Yp(*)[], _Up(*)[]>::value> > 430 : true_type {}; 431 432 #else 433 template <class _Yp, class _Tp> 434 struct __raw_pointer_compatible_with 435 : is_convertible<_Yp*, _Tp*> {}; 436 #endif // _LIBCPP_STD_VER >= 17 437 438 439 template <class _Ptr, class = void> 440 struct __is_deletable : false_type { }; 441 template <class _Ptr> 442 struct __is_deletable<_Ptr, decltype(delete std::declval<_Ptr>())> : true_type { }; 443 444 template <class _Ptr, class = void> 445 struct __is_array_deletable : false_type { }; 446 template <class _Ptr> 447 struct __is_array_deletable<_Ptr, decltype(delete[] std::declval<_Ptr>())> : true_type { }; 448 449 template <class _Dp, class _Pt, 450 class = decltype(std::declval<_Dp>()(std::declval<_Pt>()))> 451 true_type __well_formed_deleter_test(int); 452 453 template <class, class> 454 false_type __well_formed_deleter_test(...); 455 456 template <class _Dp, class _Pt> 457 struct __well_formed_deleter : decltype(std::__well_formed_deleter_test<_Dp, _Pt>(0)) {}; 458 459 template<class _Dp, class _Yp, class _Tp> 460 struct __shared_ptr_deleter_ctor_reqs 461 { 462 static const bool value = __raw_pointer_compatible_with<_Yp, _Tp>::value && 463 is_move_constructible<_Dp>::value && 464 __well_formed_deleter<_Dp, _Yp*>::value; 465 }; 466 467 #if defined(_LIBCPP_ABI_ENABLE_SHARED_PTR_TRIVIAL_ABI) 468 # define _LIBCPP_SHARED_PTR_TRIVIAL_ABI __attribute__((__trivial_abi__)) 469 #else 470 # define _LIBCPP_SHARED_PTR_TRIVIAL_ABI 471 #endif 472 473 template<class _Tp> 474 class _LIBCPP_SHARED_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS shared_ptr 475 { 476 public: 477 #if _LIBCPP_STD_VER >= 17 478 typedef weak_ptr<_Tp> weak_type; 479 typedef remove_extent_t<_Tp> element_type; 480 #else 481 typedef _Tp element_type; 482 #endif 483 484 private: 485 element_type* __ptr_; 486 __shared_weak_count* __cntrl_; 487 488 public: 489 _LIBCPP_HIDE_FROM_ABI 490 _LIBCPP_CONSTEXPR shared_ptr() _NOEXCEPT 491 : __ptr_(nullptr), 492 __cntrl_(nullptr) 493 { } 494 495 _LIBCPP_HIDE_FROM_ABI 496 _LIBCPP_CONSTEXPR shared_ptr(nullptr_t) _NOEXCEPT 497 : __ptr_(nullptr), 498 __cntrl_(nullptr) 499 { } 500 501 template<class _Yp, class = __enable_if_t< 502 _And< 503 __raw_pointer_compatible_with<_Yp, _Tp> 504 // In C++03 we get errors when trying to do SFINAE with the 505 // delete operator, so we always pretend that it's deletable. 506 // The same happens on GCC. 507 #if !defined(_LIBCPP_CXX03_LANG) && !defined(_LIBCPP_COMPILER_GCC) 508 , _If<is_array<_Tp>::value, __is_array_deletable<_Yp*>, __is_deletable<_Yp*> > 509 #endif 510 >::value 511 > > 512 _LIBCPP_HIDE_FROM_ABI explicit shared_ptr(_Yp* __p) : __ptr_(__p) { 513 unique_ptr<_Yp> __hold(__p); 514 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT; 515 typedef __shared_ptr_pointer<_Yp*, __shared_ptr_default_delete<_Tp, _Yp>, _AllocT> _CntrlBlk; 516 __cntrl_ = new _CntrlBlk(__p, __shared_ptr_default_delete<_Tp, _Yp>(), _AllocT()); 517 __hold.release(); 518 __enable_weak_this(__p, __p); 519 } 520 521 template<class _Yp, class _Dp, class = __enable_if_t<__shared_ptr_deleter_ctor_reqs<_Dp, _Yp, _Tp>::value> > 522 _LIBCPP_HIDE_FROM_ABI 523 shared_ptr(_Yp* __p, _Dp __d) 524 : __ptr_(__p) 525 { 526 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 527 try 528 { 529 #endif // _LIBCPP_HAS_NO_EXCEPTIONS 530 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT; 531 typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT> _CntrlBlk; 532 #ifndef _LIBCPP_CXX03_LANG 533 __cntrl_ = new _CntrlBlk(__p, _VSTD::move(__d), _AllocT()); 534 #else 535 __cntrl_ = new _CntrlBlk(__p, __d, _AllocT()); 536 #endif // not _LIBCPP_CXX03_LANG 537 __enable_weak_this(__p, __p); 538 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 539 } 540 catch (...) 541 { 542 __d(__p); 543 throw; 544 } 545 #endif // _LIBCPP_HAS_NO_EXCEPTIONS 546 } 547 548 template<class _Yp, class _Dp, class _Alloc, class = __enable_if_t<__shared_ptr_deleter_ctor_reqs<_Dp, _Yp, _Tp>::value> > 549 _LIBCPP_HIDE_FROM_ABI 550 shared_ptr(_Yp* __p, _Dp __d, _Alloc __a) 551 : __ptr_(__p) 552 { 553 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 554 try 555 { 556 #endif // _LIBCPP_HAS_NO_EXCEPTIONS 557 typedef __shared_ptr_pointer<_Yp*, _Dp, _Alloc> _CntrlBlk; 558 typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2; 559 typedef __allocator_destructor<_A2> _D2; 560 _A2 __a2(__a); 561 unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1)); 562 ::new ((void*)_VSTD::addressof(*__hold2.get())) 563 #ifndef _LIBCPP_CXX03_LANG 564 _CntrlBlk(__p, _VSTD::move(__d), __a); 565 #else 566 _CntrlBlk(__p, __d, __a); 567 #endif // not _LIBCPP_CXX03_LANG 568 __cntrl_ = _VSTD::addressof(*__hold2.release()); 569 __enable_weak_this(__p, __p); 570 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 571 } 572 catch (...) 573 { 574 __d(__p); 575 throw; 576 } 577 #endif // _LIBCPP_HAS_NO_EXCEPTIONS 578 } 579 580 template<class _Dp> 581 _LIBCPP_HIDE_FROM_ABI 582 shared_ptr(nullptr_t __p, _Dp __d) 583 : __ptr_(nullptr) 584 { 585 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 586 try 587 { 588 #endif // _LIBCPP_HAS_NO_EXCEPTIONS 589 typedef typename __shared_ptr_default_allocator<_Tp>::type _AllocT; 590 typedef __shared_ptr_pointer<nullptr_t, _Dp, _AllocT> _CntrlBlk; 591 #ifndef _LIBCPP_CXX03_LANG 592 __cntrl_ = new _CntrlBlk(__p, _VSTD::move(__d), _AllocT()); 593 #else 594 __cntrl_ = new _CntrlBlk(__p, __d, _AllocT()); 595 #endif // not _LIBCPP_CXX03_LANG 596 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 597 } 598 catch (...) 599 { 600 __d(__p); 601 throw; 602 } 603 #endif // _LIBCPP_HAS_NO_EXCEPTIONS 604 } 605 606 template<class _Dp, class _Alloc> 607 _LIBCPP_HIDE_FROM_ABI 608 shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a) 609 : __ptr_(nullptr) 610 { 611 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 612 try 613 { 614 #endif // _LIBCPP_HAS_NO_EXCEPTIONS 615 typedef __shared_ptr_pointer<nullptr_t, _Dp, _Alloc> _CntrlBlk; 616 typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2; 617 typedef __allocator_destructor<_A2> _D2; 618 _A2 __a2(__a); 619 unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1)); 620 ::new ((void*)_VSTD::addressof(*__hold2.get())) 621 #ifndef _LIBCPP_CXX03_LANG 622 _CntrlBlk(__p, _VSTD::move(__d), __a); 623 #else 624 _CntrlBlk(__p, __d, __a); 625 #endif // not _LIBCPP_CXX03_LANG 626 __cntrl_ = _VSTD::addressof(*__hold2.release()); 627 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS 628 } 629 catch (...) 630 { 631 __d(__p); 632 throw; 633 } 634 #endif // _LIBCPP_HAS_NO_EXCEPTIONS 635 } 636 637 template<class _Yp> 638 _LIBCPP_HIDE_FROM_ABI 639 shared_ptr(const shared_ptr<_Yp>& __r, element_type *__p) _NOEXCEPT 640 : __ptr_(__p), 641 __cntrl_(__r.__cntrl_) 642 { 643 if (__cntrl_) 644 __cntrl_->__add_shared(); 645 } 646 647 // LWG-2996 648 // We don't backport because it is an evolutionary change. 649 #if _LIBCPP_STD_VER >= 20 650 template <class _Yp> 651 _LIBCPP_HIDE_FROM_ABI shared_ptr(shared_ptr<_Yp>&& __r, element_type* __p) noexcept 652 : __ptr_(__p), 653 __cntrl_(__r.__cntrl_) { 654 __r.__ptr_ = nullptr; 655 __r.__cntrl_ = nullptr; 656 } 657 #endif 658 659 _LIBCPP_HIDE_FROM_ABI 660 shared_ptr(const shared_ptr& __r) _NOEXCEPT 661 : __ptr_(__r.__ptr_), 662 __cntrl_(__r.__cntrl_) 663 { 664 if (__cntrl_) 665 __cntrl_->__add_shared(); 666 } 667 668 template<class _Yp, class = __enable_if_t<__compatible_with<_Yp, _Tp>::value> > 669 _LIBCPP_HIDE_FROM_ABI 670 shared_ptr(const shared_ptr<_Yp>& __r) _NOEXCEPT 671 : __ptr_(__r.__ptr_), 672 __cntrl_(__r.__cntrl_) 673 { 674 if (__cntrl_) 675 __cntrl_->__add_shared(); 676 } 677 678 _LIBCPP_HIDE_FROM_ABI 679 shared_ptr(shared_ptr&& __r) _NOEXCEPT 680 : __ptr_(__r.__ptr_), 681 __cntrl_(__r.__cntrl_) 682 { 683 __r.__ptr_ = nullptr; 684 __r.__cntrl_ = nullptr; 685 } 686 687 template<class _Yp, class = __enable_if_t<__compatible_with<_Yp, _Tp>::value> > 688 _LIBCPP_HIDE_FROM_ABI 689 shared_ptr(shared_ptr<_Yp>&& __r) _NOEXCEPT 690 : __ptr_(__r.__ptr_), 691 __cntrl_(__r.__cntrl_) 692 { 693 __r.__ptr_ = nullptr; 694 __r.__cntrl_ = nullptr; 695 } 696 697 template<class _Yp, class = __enable_if_t<__compatible_with<_Yp, _Tp>::value> > 698 _LIBCPP_HIDE_FROM_ABI 699 explicit shared_ptr(const weak_ptr<_Yp>& __r) 700 : __ptr_(__r.__ptr_), 701 __cntrl_(__r.__cntrl_ ? __r.__cntrl_->lock() : __r.__cntrl_) 702 { 703 if (__cntrl_ == nullptr) 704 __throw_bad_weak_ptr(); 705 } 706 707 #if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR) 708 template<class _Yp, class = __enable_if_t<is_convertible<_Yp*, element_type*>::value> > 709 _LIBCPP_HIDE_FROM_ABI 710 shared_ptr(auto_ptr<_Yp>&& __r) 711 : __ptr_(__r.get()) 712 { 713 typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<_Yp> > _CntrlBlk; 714 __cntrl_ = new _CntrlBlk(__r.get(), default_delete<_Yp>(), allocator<_Yp>()); 715 __enable_weak_this(__r.get(), __r.get()); 716 __r.release(); 717 } 718 #endif 719 720 template <class _Yp, class _Dp, class = __enable_if_t< 721 !is_lvalue_reference<_Dp>::value && 722 __compatible_with<_Yp, _Tp>::value && 723 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value 724 > > 725 _LIBCPP_HIDE_FROM_ABI 726 shared_ptr(unique_ptr<_Yp, _Dp>&& __r) 727 : __ptr_(__r.get()) 728 { 729 #if _LIBCPP_STD_VER >= 14 730 if (__ptr_ == nullptr) 731 __cntrl_ = nullptr; 732 else 733 #endif 734 { 735 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT; 736 typedef __shared_ptr_pointer<typename unique_ptr<_Yp, _Dp>::pointer, _Dp, _AllocT> _CntrlBlk; 737 __cntrl_ = new _CntrlBlk(__r.get(), std::move(__r.get_deleter()), _AllocT()); 738 __enable_weak_this(__r.get(), __r.get()); 739 } 740 __r.release(); 741 } 742 743 template <class _Yp, class _Dp, class = void, class = __enable_if_t< 744 is_lvalue_reference<_Dp>::value && 745 __compatible_with<_Yp, _Tp>::value && 746 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value 747 > > 748 _LIBCPP_HIDE_FROM_ABI 749 shared_ptr(unique_ptr<_Yp, _Dp>&& __r) 750 : __ptr_(__r.get()) 751 { 752 #if _LIBCPP_STD_VER >= 14 753 if (__ptr_ == nullptr) 754 __cntrl_ = nullptr; 755 else 756 #endif 757 { 758 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT; 759 typedef __shared_ptr_pointer<typename unique_ptr<_Yp, _Dp>::pointer, 760 reference_wrapper<__libcpp_remove_reference_t<_Dp> >, 761 _AllocT> _CntrlBlk; 762 __cntrl_ = new _CntrlBlk(__r.get(), _VSTD::ref(__r.get_deleter()), _AllocT()); 763 __enable_weak_this(__r.get(), __r.get()); 764 } 765 __r.release(); 766 } 767 768 _LIBCPP_HIDE_FROM_ABI 769 ~shared_ptr() 770 { 771 if (__cntrl_) 772 __cntrl_->__release_shared(); 773 } 774 775 _LIBCPP_HIDE_FROM_ABI 776 shared_ptr<_Tp>& operator=(const shared_ptr& __r) _NOEXCEPT 777 { 778 shared_ptr(__r).swap(*this); 779 return *this; 780 } 781 782 template<class _Yp, class = __enable_if_t<__compatible_with<_Yp, _Tp>::value> > 783 _LIBCPP_HIDE_FROM_ABI 784 shared_ptr<_Tp>& operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT 785 { 786 shared_ptr(__r).swap(*this); 787 return *this; 788 } 789 790 _LIBCPP_HIDE_FROM_ABI 791 shared_ptr<_Tp>& operator=(shared_ptr&& __r) _NOEXCEPT 792 { 793 shared_ptr(_VSTD::move(__r)).swap(*this); 794 return *this; 795 } 796 797 template<class _Yp, class = __enable_if_t<__compatible_with<_Yp, _Tp>::value> > 798 _LIBCPP_HIDE_FROM_ABI 799 shared_ptr<_Tp>& operator=(shared_ptr<_Yp>&& __r) 800 { 801 shared_ptr(_VSTD::move(__r)).swap(*this); 802 return *this; 803 } 804 805 #if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR) 806 template<class _Yp, class = __enable_if_t< 807 !is_array<_Yp>::value && 808 is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value 809 > > 810 _LIBCPP_HIDE_FROM_ABI 811 shared_ptr<_Tp>& operator=(auto_ptr<_Yp>&& __r) 812 { 813 shared_ptr(_VSTD::move(__r)).swap(*this); 814 return *this; 815 } 816 #endif 817 818 template <class _Yp, class _Dp, class = __enable_if_t<_And< 819 __compatible_with<_Yp, _Tp>, 820 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*> 821 >::value> > 822 _LIBCPP_HIDE_FROM_ABI 823 shared_ptr<_Tp>& operator=(unique_ptr<_Yp, _Dp>&& __r) 824 { 825 shared_ptr(_VSTD::move(__r)).swap(*this); 826 return *this; 827 } 828 829 _LIBCPP_HIDE_FROM_ABI 830 void swap(shared_ptr& __r) _NOEXCEPT 831 { 832 _VSTD::swap(__ptr_, __r.__ptr_); 833 _VSTD::swap(__cntrl_, __r.__cntrl_); 834 } 835 836 _LIBCPP_HIDE_FROM_ABI 837 void reset() _NOEXCEPT 838 { 839 shared_ptr().swap(*this); 840 } 841 842 template<class _Yp, class = __enable_if_t< 843 __raw_pointer_compatible_with<_Yp, _Tp>::value 844 > > 845 _LIBCPP_HIDE_FROM_ABI 846 void reset(_Yp* __p) 847 { 848 shared_ptr(__p).swap(*this); 849 } 850 851 template<class _Yp, class _Dp, class = __enable_if_t< 852 __shared_ptr_deleter_ctor_reqs<_Dp, _Yp, _Tp>::value> > 853 _LIBCPP_HIDE_FROM_ABI 854 void reset(_Yp* __p, _Dp __d) 855 { 856 shared_ptr(__p, __d).swap(*this); 857 } 858 859 template<class _Yp, class _Dp, class _Alloc, class = __enable_if_t< 860 __shared_ptr_deleter_ctor_reqs<_Dp, _Yp, _Tp>::value> > 861 _LIBCPP_HIDE_FROM_ABI 862 void reset(_Yp* __p, _Dp __d, _Alloc __a) 863 { 864 shared_ptr(__p, __d, __a).swap(*this); 865 } 866 867 _LIBCPP_HIDE_FROM_ABI 868 element_type* get() const _NOEXCEPT 869 { 870 return __ptr_; 871 } 872 873 _LIBCPP_HIDE_FROM_ABI 874 __add_lvalue_reference_t<element_type> operator*() const _NOEXCEPT 875 { 876 return *__ptr_; 877 } 878 879 _LIBCPP_HIDE_FROM_ABI 880 element_type* operator->() const _NOEXCEPT 881 { 882 static_assert(!is_array<_Tp>::value, 883 "std::shared_ptr<T>::operator-> is only valid when T is not an array type."); 884 return __ptr_; 885 } 886 887 _LIBCPP_HIDE_FROM_ABI 888 long use_count() const _NOEXCEPT 889 { 890 return __cntrl_ ? __cntrl_->use_count() : 0; 891 } 892 893 _LIBCPP_HIDE_FROM_ABI 894 bool unique() const _NOEXCEPT 895 { 896 return use_count() == 1; 897 } 898 899 _LIBCPP_HIDE_FROM_ABI 900 explicit operator bool() const _NOEXCEPT 901 { 902 return get() != nullptr; 903 } 904 905 template <class _Up> 906 _LIBCPP_HIDE_FROM_ABI 907 bool owner_before(shared_ptr<_Up> const& __p) const _NOEXCEPT 908 { 909 return __cntrl_ < __p.__cntrl_; 910 } 911 912 template <class _Up> 913 _LIBCPP_HIDE_FROM_ABI 914 bool owner_before(weak_ptr<_Up> const& __p) const _NOEXCEPT 915 { 916 return __cntrl_ < __p.__cntrl_; 917 } 918 919 _LIBCPP_HIDE_FROM_ABI 920 bool __owner_equivalent(const shared_ptr& __p) const 921 { 922 return __cntrl_ == __p.__cntrl_; 923 } 924 925 #if _LIBCPP_STD_VER >= 17 926 _LIBCPP_HIDE_FROM_ABI 927 __add_lvalue_reference_t<element_type> operator[](ptrdiff_t __i) const 928 { 929 static_assert(is_array<_Tp>::value, 930 "std::shared_ptr<T>::operator[] is only valid when T is an array type."); 931 return __ptr_[__i]; 932 } 933 #endif 934 935 #ifndef _LIBCPP_HAS_NO_RTTI 936 template <class _Dp> 937 _LIBCPP_HIDE_FROM_ABI 938 _Dp* __get_deleter() const _NOEXCEPT 939 { 940 return static_cast<_Dp*>(__cntrl_ 941 ? const_cast<void *>(__cntrl_->__get_deleter(typeid(_Dp))) 942 : nullptr); 943 } 944 #endif // _LIBCPP_HAS_NO_RTTI 945 946 template<class _Yp, class _CntrlBlk> 947 _LIBCPP_HIDE_FROM_ABI 948 static shared_ptr<_Tp> __create_with_control_block(_Yp* __p, _CntrlBlk* __cntrl) _NOEXCEPT 949 { 950 shared_ptr<_Tp> __r; 951 __r.__ptr_ = __p; 952 __r.__cntrl_ = __cntrl; 953 __r.__enable_weak_this(__r.__ptr_, __r.__ptr_); 954 return __r; 955 } 956 957 private: 958 template <class _Yp, bool = is_function<_Yp>::value> 959 struct __shared_ptr_default_allocator 960 { 961 typedef allocator<_Yp> type; 962 }; 963 964 template <class _Yp> 965 struct __shared_ptr_default_allocator<_Yp, true> 966 { 967 typedef allocator<__shared_ptr_dummy_rebind_allocator_type> type; 968 }; 969 970 template <class _Yp, class _OrigPtr, class = __enable_if_t< 971 is_convertible<_OrigPtr*, const enable_shared_from_this<_Yp>*>::value 972 > > 973 _LIBCPP_HIDE_FROM_ABI 974 void __enable_weak_this(const enable_shared_from_this<_Yp>* __e, _OrigPtr* __ptr) _NOEXCEPT 975 { 976 typedef __remove_cv_t<_Yp> _RawYp; 977 if (__e && __e->__weak_this_.expired()) 978 { 979 __e->__weak_this_ = shared_ptr<_RawYp>(*this, 980 const_cast<_RawYp*>(static_cast<const _Yp*>(__ptr))); 981 } 982 } 983 984 _LIBCPP_HIDE_FROM_ABI void __enable_weak_this(...) _NOEXCEPT { } 985 986 template <class, class _Yp> 987 struct __shared_ptr_default_delete 988 : default_delete<_Yp> 989 { }; 990 991 template <class _Yp, class _Un, size_t _Sz> 992 struct __shared_ptr_default_delete<_Yp[_Sz], _Un> 993 : default_delete<_Yp[]> 994 { }; 995 996 template <class _Yp, class _Un> 997 struct __shared_ptr_default_delete<_Yp[], _Un> 998 : default_delete<_Yp[]> 999 { }; 1000 1001 template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr; 1002 template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr; 1003 }; 1004 1005 #if _LIBCPP_STD_VER >= 17 1006 template<class _Tp> 1007 shared_ptr(weak_ptr<_Tp>) -> shared_ptr<_Tp>; 1008 template<class _Tp, class _Dp> 1009 shared_ptr(unique_ptr<_Tp, _Dp>) -> shared_ptr<_Tp>; 1010 #endif 1011 1012 // 1013 // std::allocate_shared and std::make_shared 1014 // 1015 template<class _Tp, class _Alloc, class ..._Args, class = __enable_if_t<!is_array<_Tp>::value> > 1016 _LIBCPP_HIDE_FROM_ABI 1017 shared_ptr<_Tp> allocate_shared(const _Alloc& __a, _Args&& ...__args) 1018 { 1019 using _ControlBlock = __shared_ptr_emplace<_Tp, _Alloc>; 1020 using _ControlBlockAllocator = typename __allocator_traits_rebind<_Alloc, _ControlBlock>::type; 1021 __allocation_guard<_ControlBlockAllocator> __guard(__a, 1); 1022 ::new ((void*)_VSTD::addressof(*__guard.__get())) _ControlBlock(__a, _VSTD::forward<_Args>(__args)...); 1023 auto __control_block = __guard.__release_ptr(); 1024 return shared_ptr<_Tp>::__create_with_control_block((*__control_block).__get_elem(), _VSTD::addressof(*__control_block)); 1025 } 1026 1027 template<class _Tp, class ..._Args, class = __enable_if_t<!is_array<_Tp>::value> > 1028 _LIBCPP_HIDE_FROM_ABI 1029 shared_ptr<_Tp> make_shared(_Args&& ...__args) 1030 { 1031 return _VSTD::allocate_shared<_Tp>(allocator<_Tp>(), _VSTD::forward<_Args>(__args)...); 1032 } 1033 1034 #if _LIBCPP_STD_VER >= 20 1035 1036 template<class _Tp, class _Alloc, __enable_if_t<!is_array<_Tp>::value, int> = 0> 1037 _LIBCPP_HIDE_FROM_ABI 1038 shared_ptr<_Tp> allocate_shared_for_overwrite(const _Alloc& __a) 1039 { 1040 using _ForOverwriteAllocator = __allocator_traits_rebind_t<_Alloc, __for_overwrite_tag>; 1041 _ForOverwriteAllocator __alloc(__a); 1042 return std::allocate_shared<_Tp>(__alloc); 1043 } 1044 1045 template<class _Tp, __enable_if_t<!is_array<_Tp>::value, int> = 0> 1046 _LIBCPP_HIDE_FROM_ABI 1047 shared_ptr<_Tp> make_shared_for_overwrite() 1048 { 1049 return std::allocate_shared_for_overwrite<_Tp>(allocator<_Tp>()); 1050 } 1051 1052 #endif // _LIBCPP_STD_VER >= 20 1053 1054 #if _LIBCPP_STD_VER >= 17 1055 1056 template <size_t _Alignment> 1057 struct __sp_aligned_storage { 1058 alignas(_Alignment) char __storage[_Alignment]; 1059 }; 1060 1061 template <class _Tp, class _Alloc> 1062 struct __unbounded_array_control_block; 1063 1064 template <class _Tp, class _Alloc> 1065 struct __unbounded_array_control_block<_Tp[], _Alloc> : __shared_weak_count 1066 { 1067 _LIBCPP_HIDE_FROM_ABI constexpr 1068 _Tp* __get_data() noexcept { return __data_; } 1069 1070 _LIBCPP_HIDE_FROM_ABI 1071 explicit __unbounded_array_control_block(_Alloc const& __alloc, size_t __count, _Tp const& __arg) 1072 : __alloc_(__alloc), __count_(__count) 1073 { 1074 std::__uninitialized_allocator_fill_n_multidimensional(__alloc_, std::begin(__data_), __count_, __arg); 1075 } 1076 1077 _LIBCPP_HIDE_FROM_ABI 1078 explicit __unbounded_array_control_block(_Alloc const& __alloc, size_t __count) 1079 : __alloc_(__alloc), __count_(__count) 1080 { 1081 #if _LIBCPP_STD_VER >= 20 1082 if constexpr (is_same_v<typename _Alloc::value_type, __for_overwrite_tag>) { 1083 // We are purposefully not using an allocator-aware default construction because the spec says so. 1084 // There's currently no way of expressing default initialization in an allocator-aware manner anyway. 1085 std::uninitialized_default_construct_n(std::begin(__data_), __count_); 1086 } else { 1087 std::__uninitialized_allocator_value_construct_n_multidimensional(__alloc_, std::begin(__data_), __count_); 1088 } 1089 #else 1090 std::__uninitialized_allocator_value_construct_n_multidimensional(__alloc_, std::begin(__data_), __count_); 1091 #endif 1092 } 1093 1094 // Returns the number of bytes required to store a control block followed by the given number 1095 // of elements of _Tp, with the whole storage being aligned to a multiple of _Tp's alignment. 1096 _LIBCPP_HIDE_FROM_ABI 1097 static constexpr size_t __bytes_for(size_t __elements) { 1098 // When there's 0 elements, the control block alone is enough since it holds one element. 1099 // Otherwise, we allocate one fewer element than requested because the control block already 1100 // holds one. Also, we use the bitwise formula below to ensure that we allocate enough bytes 1101 // for the whole allocation to be a multiple of _Tp's alignment. That formula is taken from [1]. 1102 // 1103 // [1]: https://en.wikipedia.org/wiki/Data_structure_alignment#Computing_padding 1104 size_t __bytes = __elements == 0 ? sizeof(__unbounded_array_control_block) 1105 : (__elements - 1) * sizeof(_Tp) + sizeof(__unbounded_array_control_block); 1106 constexpr size_t __align = alignof(_Tp); 1107 return (__bytes + __align - 1) & ~(__align - 1); 1108 } 1109 1110 _LIBCPP_HIDE_FROM_ABI_VIRTUAL 1111 ~__unbounded_array_control_block() override { } // can't be `= default` because of the sometimes-non-trivial union member __data_ 1112 1113 private: 1114 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override { 1115 #if _LIBCPP_STD_VER >= 20 1116 if constexpr (is_same_v<typename _Alloc::value_type, __for_overwrite_tag>) { 1117 std::__reverse_destroy(__data_, __data_ + __count_); 1118 } else { 1119 __allocator_traits_rebind_t<_Alloc, _Tp> __value_alloc(__alloc_); 1120 std::__allocator_destroy_multidimensional(__value_alloc, __data_, __data_ + __count_); 1121 } 1122 #else 1123 __allocator_traits_rebind_t<_Alloc, _Tp> __value_alloc(__alloc_); 1124 std::__allocator_destroy_multidimensional(__value_alloc, __data_, __data_ + __count_); 1125 #endif 1126 } 1127 1128 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared_weak() _NOEXCEPT override { 1129 using _AlignedStorage = __sp_aligned_storage<alignof(__unbounded_array_control_block)>; 1130 using _StorageAlloc = __allocator_traits_rebind_t<_Alloc, _AlignedStorage>; 1131 using _PointerTraits = pointer_traits<typename allocator_traits<_StorageAlloc>::pointer>; 1132 1133 _StorageAlloc __tmp(__alloc_); 1134 __alloc_.~_Alloc(); 1135 size_t __size = __unbounded_array_control_block::__bytes_for(__count_); 1136 _AlignedStorage* __storage = reinterpret_cast<_AlignedStorage*>(this); 1137 allocator_traits<_StorageAlloc>::deallocate(__tmp, _PointerTraits::pointer_to(*__storage), __size); 1138 } 1139 1140 _LIBCPP_NO_UNIQUE_ADDRESS _Alloc __alloc_; 1141 size_t __count_; 1142 union { 1143 _Tp __data_[1]; 1144 }; 1145 }; 1146 1147 template<class _Array, class _Alloc, class... _Arg> 1148 _LIBCPP_HIDE_FROM_ABI 1149 shared_ptr<_Array> __allocate_shared_unbounded_array(const _Alloc& __a, size_t __n, _Arg&& ...__arg) 1150 { 1151 static_assert(__libcpp_is_unbounded_array<_Array>::value); 1152 // We compute the number of bytes necessary to hold the control block and the 1153 // array elements. Then, we allocate an array of properly-aligned dummy structs 1154 // large enough to hold the control block and array. This allows shifting the 1155 // burden of aligning memory properly from us to the allocator. 1156 using _ControlBlock = __unbounded_array_control_block<_Array, _Alloc>; 1157 using _AlignedStorage = __sp_aligned_storage<alignof(_ControlBlock)>; 1158 using _StorageAlloc = __allocator_traits_rebind_t<_Alloc, _AlignedStorage>; 1159 __allocation_guard<_StorageAlloc> __guard(__a, _ControlBlock::__bytes_for(__n) / sizeof(_AlignedStorage)); 1160 _ControlBlock* __control_block = reinterpret_cast<_ControlBlock*>(std::addressof(*__guard.__get())); 1161 std::__construct_at(__control_block, __a, __n, std::forward<_Arg>(__arg)...); 1162 __guard.__release_ptr(); 1163 return shared_ptr<_Array>::__create_with_control_block(__control_block->__get_data(), __control_block); 1164 } 1165 1166 template <class _Tp, class _Alloc> 1167 struct __bounded_array_control_block; 1168 1169 template <class _Tp, size_t _Count, class _Alloc> 1170 struct __bounded_array_control_block<_Tp[_Count], _Alloc> 1171 : __shared_weak_count 1172 { 1173 _LIBCPP_HIDE_FROM_ABI constexpr 1174 _Tp* __get_data() noexcept { return __data_; } 1175 1176 _LIBCPP_HIDE_FROM_ABI 1177 explicit __bounded_array_control_block(_Alloc const& __alloc, _Tp const& __arg) : __alloc_(__alloc) { 1178 std::__uninitialized_allocator_fill_n_multidimensional(__alloc_, std::addressof(__data_[0]), _Count, __arg); 1179 } 1180 1181 _LIBCPP_HIDE_FROM_ABI 1182 explicit __bounded_array_control_block(_Alloc const& __alloc) : __alloc_(__alloc) { 1183 #if _LIBCPP_STD_VER >= 20 1184 if constexpr (is_same_v<typename _Alloc::value_type, __for_overwrite_tag>) { 1185 // We are purposefully not using an allocator-aware default construction because the spec says so. 1186 // There's currently no way of expressing default initialization in an allocator-aware manner anyway. 1187 std::uninitialized_default_construct_n(std::addressof(__data_[0]), _Count); 1188 } else { 1189 std::__uninitialized_allocator_value_construct_n_multidimensional(__alloc_, std::addressof(__data_[0]), _Count); 1190 } 1191 #else 1192 std::__uninitialized_allocator_value_construct_n_multidimensional(__alloc_, std::addressof(__data_[0]), _Count); 1193 #endif 1194 } 1195 1196 _LIBCPP_HIDE_FROM_ABI_VIRTUAL 1197 ~__bounded_array_control_block() override { } // can't be `= default` because of the sometimes-non-trivial union member __data_ 1198 1199 private: 1200 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override { 1201 #if _LIBCPP_STD_VER >= 20 1202 if constexpr (is_same_v<typename _Alloc::value_type, __for_overwrite_tag>) { 1203 std::__reverse_destroy(__data_, __data_ + _Count); 1204 } else { 1205 __allocator_traits_rebind_t<_Alloc, _Tp> __value_alloc(__alloc_); 1206 std::__allocator_destroy_multidimensional(__value_alloc, __data_, __data_ + _Count); 1207 } 1208 #else 1209 __allocator_traits_rebind_t<_Alloc, _Tp> __value_alloc(__alloc_); 1210 std::__allocator_destroy_multidimensional(__value_alloc, __data_, __data_ + _Count); 1211 #endif 1212 } 1213 1214 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared_weak() _NOEXCEPT override { 1215 using _ControlBlockAlloc = __allocator_traits_rebind_t<_Alloc, __bounded_array_control_block>; 1216 using _PointerTraits = pointer_traits<typename allocator_traits<_ControlBlockAlloc>::pointer>; 1217 1218 _ControlBlockAlloc __tmp(__alloc_); 1219 __alloc_.~_Alloc(); 1220 allocator_traits<_ControlBlockAlloc>::deallocate(__tmp, _PointerTraits::pointer_to(*this), sizeof(*this)); 1221 } 1222 1223 _LIBCPP_NO_UNIQUE_ADDRESS _Alloc __alloc_; 1224 union { 1225 _Tp __data_[_Count]; 1226 }; 1227 }; 1228 1229 template<class _Array, class _Alloc, class... _Arg> 1230 _LIBCPP_HIDE_FROM_ABI 1231 shared_ptr<_Array> __allocate_shared_bounded_array(const _Alloc& __a, _Arg&& ...__arg) 1232 { 1233 static_assert(__libcpp_is_bounded_array<_Array>::value); 1234 using _ControlBlock = __bounded_array_control_block<_Array, _Alloc>; 1235 using _ControlBlockAlloc = __allocator_traits_rebind_t<_Alloc, _ControlBlock>; 1236 1237 __allocation_guard<_ControlBlockAlloc> __guard(__a, 1); 1238 _ControlBlock* __control_block = reinterpret_cast<_ControlBlock*>(std::addressof(*__guard.__get())); 1239 std::__construct_at(__control_block, __a, std::forward<_Arg>(__arg)...); 1240 __guard.__release_ptr(); 1241 return shared_ptr<_Array>::__create_with_control_block(__control_block->__get_data(), __control_block); 1242 } 1243 1244 #endif // _LIBCPP_STD_VER >= 17 1245 1246 #if _LIBCPP_STD_VER >= 20 1247 1248 // bounded array variants 1249 template<class _Tp, class _Alloc, class = __enable_if_t<is_bounded_array<_Tp>::value>> 1250 _LIBCPP_HIDE_FROM_ABI 1251 shared_ptr<_Tp> allocate_shared(const _Alloc& __a) 1252 { 1253 return std::__allocate_shared_bounded_array<_Tp>(__a); 1254 } 1255 1256 template<class _Tp, class _Alloc, class = __enable_if_t<is_bounded_array<_Tp>::value>> 1257 _LIBCPP_HIDE_FROM_ABI 1258 shared_ptr<_Tp> allocate_shared(const _Alloc& __a, const remove_extent_t<_Tp>& __u) 1259 { 1260 return std::__allocate_shared_bounded_array<_Tp>(__a, __u); 1261 } 1262 1263 template<class _Tp, class _Alloc, __enable_if_t<is_bounded_array<_Tp>::value, int> = 0> 1264 _LIBCPP_HIDE_FROM_ABI 1265 shared_ptr<_Tp> allocate_shared_for_overwrite(const _Alloc& __a) 1266 { 1267 using _ForOverwriteAllocator = __allocator_traits_rebind_t<_Alloc, __for_overwrite_tag>; 1268 _ForOverwriteAllocator __alloc(__a); 1269 return std::__allocate_shared_bounded_array<_Tp>(__alloc); 1270 } 1271 1272 template<class _Tp, class = __enable_if_t<is_bounded_array<_Tp>::value>> 1273 _LIBCPP_HIDE_FROM_ABI 1274 shared_ptr<_Tp> make_shared() 1275 { 1276 return std::__allocate_shared_bounded_array<_Tp>(allocator<_Tp>()); 1277 } 1278 1279 template<class _Tp, class = __enable_if_t<is_bounded_array<_Tp>::value>> 1280 _LIBCPP_HIDE_FROM_ABI 1281 shared_ptr<_Tp> make_shared(const remove_extent_t<_Tp>& __u) 1282 { 1283 return std::__allocate_shared_bounded_array<_Tp>(allocator<_Tp>(), __u); 1284 } 1285 1286 template<class _Tp, __enable_if_t<is_bounded_array<_Tp>::value, int> = 0> 1287 _LIBCPP_HIDE_FROM_ABI 1288 shared_ptr<_Tp> make_shared_for_overwrite() 1289 { 1290 return std::__allocate_shared_bounded_array<_Tp>(allocator<__for_overwrite_tag>()); 1291 } 1292 1293 // unbounded array variants 1294 template<class _Tp, class _Alloc, class = __enable_if_t<is_unbounded_array<_Tp>::value>> 1295 _LIBCPP_HIDE_FROM_ABI 1296 shared_ptr<_Tp> allocate_shared(const _Alloc& __a, size_t __n) 1297 { 1298 return std::__allocate_shared_unbounded_array<_Tp>(__a, __n); 1299 } 1300 1301 template<class _Tp, class _Alloc, class = __enable_if_t<is_unbounded_array<_Tp>::value>> 1302 _LIBCPP_HIDE_FROM_ABI 1303 shared_ptr<_Tp> allocate_shared(const _Alloc& __a, size_t __n, const remove_extent_t<_Tp>& __u) 1304 { 1305 return std::__allocate_shared_unbounded_array<_Tp>(__a, __n, __u); 1306 } 1307 1308 template<class _Tp, class _Alloc, __enable_if_t<is_unbounded_array<_Tp>::value, int> = 0> 1309 _LIBCPP_HIDE_FROM_ABI 1310 shared_ptr<_Tp> allocate_shared_for_overwrite(const _Alloc& __a, size_t __n) 1311 { 1312 using _ForOverwriteAllocator = __allocator_traits_rebind_t<_Alloc, __for_overwrite_tag>; 1313 _ForOverwriteAllocator __alloc(__a); 1314 return std::__allocate_shared_unbounded_array<_Tp>(__alloc, __n); 1315 } 1316 1317 template<class _Tp, class = __enable_if_t<is_unbounded_array<_Tp>::value>> 1318 _LIBCPP_HIDE_FROM_ABI 1319 shared_ptr<_Tp> make_shared(size_t __n) 1320 { 1321 return std::__allocate_shared_unbounded_array<_Tp>(allocator<_Tp>(), __n); 1322 } 1323 1324 template<class _Tp, class = __enable_if_t<is_unbounded_array<_Tp>::value>> 1325 _LIBCPP_HIDE_FROM_ABI 1326 shared_ptr<_Tp> make_shared(size_t __n, const remove_extent_t<_Tp>& __u) 1327 { 1328 return std::__allocate_shared_unbounded_array<_Tp>(allocator<_Tp>(), __n, __u); 1329 } 1330 1331 template<class _Tp, __enable_if_t<is_unbounded_array<_Tp>::value, int> = 0> 1332 _LIBCPP_HIDE_FROM_ABI 1333 shared_ptr<_Tp> make_shared_for_overwrite(size_t __n) 1334 { 1335 return std::__allocate_shared_unbounded_array<_Tp>(allocator<__for_overwrite_tag>(), __n); 1336 } 1337 1338 #endif // _LIBCPP_STD_VER >= 20 1339 1340 template<class _Tp, class _Up> 1341 inline _LIBCPP_INLINE_VISIBILITY 1342 bool 1343 operator==(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT 1344 { 1345 return __x.get() == __y.get(); 1346 } 1347 1348 #if _LIBCPP_STD_VER <= 17 1349 1350 template<class _Tp, class _Up> 1351 inline _LIBCPP_INLINE_VISIBILITY 1352 bool 1353 operator!=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT 1354 { 1355 return !(__x == __y); 1356 } 1357 1358 template<class _Tp, class _Up> 1359 inline _LIBCPP_INLINE_VISIBILITY 1360 bool 1361 operator<(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT 1362 { 1363 #if _LIBCPP_STD_VER <= 11 1364 typedef typename common_type<_Tp*, _Up*>::type _Vp; 1365 return less<_Vp>()(__x.get(), __y.get()); 1366 #else 1367 return less<>()(__x.get(), __y.get()); 1368 #endif 1369 1370 } 1371 1372 template<class _Tp, class _Up> 1373 inline _LIBCPP_INLINE_VISIBILITY 1374 bool 1375 operator>(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT 1376 { 1377 return __y < __x; 1378 } 1379 1380 template<class _Tp, class _Up> 1381 inline _LIBCPP_INLINE_VISIBILITY 1382 bool 1383 operator<=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT 1384 { 1385 return !(__y < __x); 1386 } 1387 1388 template<class _Tp, class _Up> 1389 inline _LIBCPP_INLINE_VISIBILITY 1390 bool 1391 operator>=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT 1392 { 1393 return !(__x < __y); 1394 } 1395 1396 #endif // _LIBCPP_STD_VER <= 17 1397 1398 #if _LIBCPP_STD_VER >= 20 1399 template<class _Tp, class _Up> 1400 _LIBCPP_HIDE_FROM_ABI strong_ordering 1401 operator<=>(shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) noexcept 1402 { 1403 return compare_three_way()(__x.get(), __y.get()); 1404 } 1405 #endif 1406 1407 template<class _Tp> 1408 inline _LIBCPP_INLINE_VISIBILITY 1409 bool 1410 operator==(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT 1411 { 1412 return !__x; 1413 } 1414 1415 #if _LIBCPP_STD_VER <= 17 1416 1417 template<class _Tp> 1418 inline _LIBCPP_INLINE_VISIBILITY 1419 bool 1420 operator==(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT 1421 { 1422 return !__x; 1423 } 1424 1425 template<class _Tp> 1426 inline _LIBCPP_INLINE_VISIBILITY 1427 bool 1428 operator!=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT 1429 { 1430 return static_cast<bool>(__x); 1431 } 1432 1433 template<class _Tp> 1434 inline _LIBCPP_INLINE_VISIBILITY 1435 bool 1436 operator!=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT 1437 { 1438 return static_cast<bool>(__x); 1439 } 1440 1441 template<class _Tp> 1442 inline _LIBCPP_INLINE_VISIBILITY 1443 bool 1444 operator<(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT 1445 { 1446 return less<_Tp*>()(__x.get(), nullptr); 1447 } 1448 1449 template<class _Tp> 1450 inline _LIBCPP_INLINE_VISIBILITY 1451 bool 1452 operator<(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT 1453 { 1454 return less<_Tp*>()(nullptr, __x.get()); 1455 } 1456 1457 template<class _Tp> 1458 inline _LIBCPP_INLINE_VISIBILITY 1459 bool 1460 operator>(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT 1461 { 1462 return nullptr < __x; 1463 } 1464 1465 template<class _Tp> 1466 inline _LIBCPP_INLINE_VISIBILITY 1467 bool 1468 operator>(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT 1469 { 1470 return __x < nullptr; 1471 } 1472 1473 template<class _Tp> 1474 inline _LIBCPP_INLINE_VISIBILITY 1475 bool 1476 operator<=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT 1477 { 1478 return !(nullptr < __x); 1479 } 1480 1481 template<class _Tp> 1482 inline _LIBCPP_INLINE_VISIBILITY 1483 bool 1484 operator<=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT 1485 { 1486 return !(__x < nullptr); 1487 } 1488 1489 template<class _Tp> 1490 inline _LIBCPP_INLINE_VISIBILITY 1491 bool 1492 operator>=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT 1493 { 1494 return !(__x < nullptr); 1495 } 1496 1497 template<class _Tp> 1498 inline _LIBCPP_INLINE_VISIBILITY 1499 bool 1500 operator>=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT 1501 { 1502 return !(nullptr < __x); 1503 } 1504 1505 #endif // _LIBCPP_STD_VER <= 17 1506 1507 #if _LIBCPP_STD_VER >= 20 1508 template<class _Tp> 1509 _LIBCPP_HIDE_FROM_ABI strong_ordering 1510 operator<=>(shared_ptr<_Tp> const& __x, nullptr_t) noexcept 1511 { 1512 return compare_three_way()(__x.get(), static_cast<typename shared_ptr<_Tp>::element_type*>(nullptr)); 1513 } 1514 #endif 1515 1516 template<class _Tp> 1517 inline _LIBCPP_INLINE_VISIBILITY 1518 void 1519 swap(shared_ptr<_Tp>& __x, shared_ptr<_Tp>& __y) _NOEXCEPT 1520 { 1521 __x.swap(__y); 1522 } 1523 1524 template<class _Tp, class _Up> 1525 inline _LIBCPP_INLINE_VISIBILITY 1526 shared_ptr<_Tp> 1527 static_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT 1528 { 1529 return shared_ptr<_Tp>(__r, 1530 static_cast< 1531 typename shared_ptr<_Tp>::element_type*>(__r.get())); 1532 } 1533 1534 // LWG-2996 1535 // We don't backport because it is an evolutionary change. 1536 #if _LIBCPP_STD_VER >= 20 1537 template <class _Tp, class _Up> 1538 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> static_pointer_cast(shared_ptr<_Up>&& __r) noexcept { 1539 return shared_ptr<_Tp>(std::move(__r), static_cast<typename shared_ptr<_Tp>::element_type*>(__r.get())); 1540 } 1541 #endif 1542 1543 template<class _Tp, class _Up> 1544 inline _LIBCPP_INLINE_VISIBILITY 1545 shared_ptr<_Tp> 1546 dynamic_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT 1547 { 1548 typedef typename shared_ptr<_Tp>::element_type _ET; 1549 _ET* __p = dynamic_cast<_ET*>(__r.get()); 1550 return __p ? shared_ptr<_Tp>(__r, __p) : shared_ptr<_Tp>(); 1551 } 1552 1553 // LWG-2996 1554 // We don't backport because it is an evolutionary change. 1555 #if _LIBCPP_STD_VER >= 20 1556 template <class _Tp, class _Up> 1557 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> dynamic_pointer_cast(shared_ptr<_Up>&& __r) noexcept { 1558 auto* __p = dynamic_cast<typename shared_ptr<_Tp>::element_type*>(__r.get()); 1559 return __p ? shared_ptr<_Tp>(std::move(__r), __p) : shared_ptr<_Tp>(); 1560 } 1561 #endif 1562 1563 template<class _Tp, class _Up> 1564 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> 1565 const_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT 1566 { 1567 typedef typename shared_ptr<_Tp>::element_type _RTp; 1568 return shared_ptr<_Tp>(__r, const_cast<_RTp*>(__r.get())); 1569 } 1570 1571 // LWG-2996 1572 // We don't backport because it is an evolutionary change. 1573 #if _LIBCPP_STD_VER >= 20 1574 template <class _Tp, class _Up> 1575 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> const_pointer_cast(shared_ptr<_Up>&& __r) noexcept { 1576 return shared_ptr<_Tp>(std::move(__r), const_cast<typename shared_ptr<_Tp>::element_type*>(__r.get())); 1577 } 1578 #endif 1579 1580 template<class _Tp, class _Up> 1581 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> 1582 reinterpret_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT 1583 { 1584 return shared_ptr<_Tp>(__r, 1585 reinterpret_cast< 1586 typename shared_ptr<_Tp>::element_type*>(__r.get())); 1587 } 1588 1589 // LWG-2996 1590 // We don't backport because it is an evolutionary change. 1591 #if _LIBCPP_STD_VER >= 20 1592 template <class _Tp, class _Up> 1593 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> reinterpret_pointer_cast(shared_ptr<_Up>&& __r) noexcept { 1594 return shared_ptr<_Tp>(std::move(__r), reinterpret_cast<typename shared_ptr<_Tp>::element_type*>(__r.get())); 1595 } 1596 #endif 1597 1598 #ifndef _LIBCPP_HAS_NO_RTTI 1599 1600 template<class _Dp, class _Tp> 1601 inline _LIBCPP_INLINE_VISIBILITY 1602 _Dp* 1603 get_deleter(const shared_ptr<_Tp>& __p) _NOEXCEPT 1604 { 1605 return __p.template __get_deleter<_Dp>(); 1606 } 1607 1608 #endif // _LIBCPP_HAS_NO_RTTI 1609 1610 template<class _Tp> 1611 class _LIBCPP_SHARED_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS weak_ptr 1612 { 1613 public: 1614 #if _LIBCPP_STD_VER >= 17 1615 typedef remove_extent_t<_Tp> element_type; 1616 #else 1617 typedef _Tp element_type; 1618 #endif 1619 1620 private: 1621 element_type* __ptr_; 1622 __shared_weak_count* __cntrl_; 1623 1624 public: 1625 _LIBCPP_INLINE_VISIBILITY 1626 _LIBCPP_CONSTEXPR weak_ptr() _NOEXCEPT; 1627 template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(shared_ptr<_Yp> const& __r, 1628 typename enable_if<__compatible_with<_Yp, _Tp>::value, __nat*>::type = 0) 1629 _NOEXCEPT; 1630 _LIBCPP_INLINE_VISIBILITY 1631 weak_ptr(weak_ptr const& __r) _NOEXCEPT; 1632 template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp> const& __r, 1633 typename enable_if<__compatible_with<_Yp, _Tp>::value, __nat*>::type = 0) 1634 _NOEXCEPT; 1635 1636 _LIBCPP_INLINE_VISIBILITY 1637 weak_ptr(weak_ptr&& __r) _NOEXCEPT; 1638 template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp>&& __r, 1639 typename enable_if<__compatible_with<_Yp, _Tp>::value, __nat*>::type = 0) 1640 _NOEXCEPT; 1641 _LIBCPP_HIDE_FROM_ABI ~weak_ptr(); 1642 1643 _LIBCPP_INLINE_VISIBILITY 1644 weak_ptr& operator=(weak_ptr const& __r) _NOEXCEPT; 1645 template<class _Yp> 1646 typename enable_if 1647 < 1648 __compatible_with<_Yp, _Tp>::value, 1649 weak_ptr& 1650 >::type 1651 _LIBCPP_INLINE_VISIBILITY 1652 operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT; 1653 1654 _LIBCPP_INLINE_VISIBILITY 1655 weak_ptr& operator=(weak_ptr&& __r) _NOEXCEPT; 1656 template<class _Yp> 1657 typename enable_if 1658 < 1659 __compatible_with<_Yp, _Tp>::value, 1660 weak_ptr& 1661 >::type 1662 _LIBCPP_INLINE_VISIBILITY 1663 operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT; 1664 1665 template<class _Yp> 1666 typename enable_if 1667 < 1668 __compatible_with<_Yp, _Tp>::value, 1669 weak_ptr& 1670 >::type 1671 _LIBCPP_INLINE_VISIBILITY 1672 operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT; 1673 1674 _LIBCPP_INLINE_VISIBILITY 1675 void swap(weak_ptr& __r) _NOEXCEPT; 1676 _LIBCPP_INLINE_VISIBILITY 1677 void reset() _NOEXCEPT; 1678 1679 _LIBCPP_INLINE_VISIBILITY 1680 long use_count() const _NOEXCEPT 1681 {return __cntrl_ ? __cntrl_->use_count() : 0;} 1682 _LIBCPP_INLINE_VISIBILITY 1683 bool expired() const _NOEXCEPT 1684 {return __cntrl_ == nullptr || __cntrl_->use_count() == 0;} 1685 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> lock() const _NOEXCEPT; 1686 template<class _Up> 1687 _LIBCPP_INLINE_VISIBILITY 1688 bool owner_before(const shared_ptr<_Up>& __r) const _NOEXCEPT 1689 {return __cntrl_ < __r.__cntrl_;} 1690 template<class _Up> 1691 _LIBCPP_INLINE_VISIBILITY 1692 bool owner_before(const weak_ptr<_Up>& __r) const _NOEXCEPT 1693 {return __cntrl_ < __r.__cntrl_;} 1694 1695 template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr; 1696 template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr; 1697 }; 1698 1699 #if _LIBCPP_STD_VER >= 17 1700 template<class _Tp> 1701 weak_ptr(shared_ptr<_Tp>) -> weak_ptr<_Tp>; 1702 #endif 1703 1704 template<class _Tp> 1705 inline 1706 _LIBCPP_CONSTEXPR 1707 weak_ptr<_Tp>::weak_ptr() _NOEXCEPT 1708 : __ptr_(nullptr), 1709 __cntrl_(nullptr) 1710 { 1711 } 1712 1713 template<class _Tp> 1714 inline 1715 weak_ptr<_Tp>::weak_ptr(weak_ptr const& __r) _NOEXCEPT 1716 : __ptr_(__r.__ptr_), 1717 __cntrl_(__r.__cntrl_) 1718 { 1719 if (__cntrl_) 1720 __cntrl_->__add_weak(); 1721 } 1722 1723 template<class _Tp> 1724 template<class _Yp> 1725 inline 1726 weak_ptr<_Tp>::weak_ptr(shared_ptr<_Yp> const& __r, 1727 typename enable_if<__compatible_with<_Yp, _Tp>::value, __nat*>::type) 1728 _NOEXCEPT 1729 : __ptr_(__r.__ptr_), 1730 __cntrl_(__r.__cntrl_) 1731 { 1732 if (__cntrl_) 1733 __cntrl_->__add_weak(); 1734 } 1735 1736 template<class _Tp> 1737 template<class _Yp> 1738 inline 1739 weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp> const& __r, 1740 typename enable_if<__compatible_with<_Yp, _Tp>::value, __nat*>::type) 1741 _NOEXCEPT 1742 : __ptr_(__r.__ptr_), 1743 __cntrl_(__r.__cntrl_) 1744 { 1745 if (__cntrl_) 1746 __cntrl_->__add_weak(); 1747 } 1748 1749 template<class _Tp> 1750 inline 1751 weak_ptr<_Tp>::weak_ptr(weak_ptr&& __r) _NOEXCEPT 1752 : __ptr_(__r.__ptr_), 1753 __cntrl_(__r.__cntrl_) 1754 { 1755 __r.__ptr_ = nullptr; 1756 __r.__cntrl_ = nullptr; 1757 } 1758 1759 template<class _Tp> 1760 template<class _Yp> 1761 inline 1762 weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp>&& __r, 1763 typename enable_if<__compatible_with<_Yp, _Tp>::value, __nat*>::type) 1764 _NOEXCEPT 1765 : __ptr_(__r.__ptr_), 1766 __cntrl_(__r.__cntrl_) 1767 { 1768 __r.__ptr_ = nullptr; 1769 __r.__cntrl_ = nullptr; 1770 } 1771 1772 template<class _Tp> 1773 weak_ptr<_Tp>::~weak_ptr() 1774 { 1775 if (__cntrl_) 1776 __cntrl_->__release_weak(); 1777 } 1778 1779 template<class _Tp> 1780 inline 1781 weak_ptr<_Tp>& 1782 weak_ptr<_Tp>::operator=(weak_ptr const& __r) _NOEXCEPT 1783 { 1784 weak_ptr(__r).swap(*this); 1785 return *this; 1786 } 1787 1788 template<class _Tp> 1789 template<class _Yp> 1790 inline 1791 typename enable_if 1792 < 1793 __compatible_with<_Yp, _Tp>::value, 1794 weak_ptr<_Tp>& 1795 >::type 1796 weak_ptr<_Tp>::operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT 1797 { 1798 weak_ptr(__r).swap(*this); 1799 return *this; 1800 } 1801 1802 template<class _Tp> 1803 inline 1804 weak_ptr<_Tp>& 1805 weak_ptr<_Tp>::operator=(weak_ptr&& __r) _NOEXCEPT 1806 { 1807 weak_ptr(_VSTD::move(__r)).swap(*this); 1808 return *this; 1809 } 1810 1811 template<class _Tp> 1812 template<class _Yp> 1813 inline 1814 typename enable_if 1815 < 1816 __compatible_with<_Yp, _Tp>::value, 1817 weak_ptr<_Tp>& 1818 >::type 1819 weak_ptr<_Tp>::operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT 1820 { 1821 weak_ptr(_VSTD::move(__r)).swap(*this); 1822 return *this; 1823 } 1824 1825 template<class _Tp> 1826 template<class _Yp> 1827 inline 1828 typename enable_if 1829 < 1830 __compatible_with<_Yp, _Tp>::value, 1831 weak_ptr<_Tp>& 1832 >::type 1833 weak_ptr<_Tp>::operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT 1834 { 1835 weak_ptr(__r).swap(*this); 1836 return *this; 1837 } 1838 1839 template<class _Tp> 1840 inline 1841 void 1842 weak_ptr<_Tp>::swap(weak_ptr& __r) _NOEXCEPT 1843 { 1844 _VSTD::swap(__ptr_, __r.__ptr_); 1845 _VSTD::swap(__cntrl_, __r.__cntrl_); 1846 } 1847 1848 template<class _Tp> 1849 inline _LIBCPP_INLINE_VISIBILITY 1850 void 1851 swap(weak_ptr<_Tp>& __x, weak_ptr<_Tp>& __y) _NOEXCEPT 1852 { 1853 __x.swap(__y); 1854 } 1855 1856 template<class _Tp> 1857 inline 1858 void 1859 weak_ptr<_Tp>::reset() _NOEXCEPT 1860 { 1861 weak_ptr().swap(*this); 1862 } 1863 1864 template<class _Tp> 1865 shared_ptr<_Tp> 1866 weak_ptr<_Tp>::lock() const _NOEXCEPT 1867 { 1868 shared_ptr<_Tp> __r; 1869 __r.__cntrl_ = __cntrl_ ? __cntrl_->lock() : __cntrl_; 1870 if (__r.__cntrl_) 1871 __r.__ptr_ = __ptr_; 1872 return __r; 1873 } 1874 1875 #if _LIBCPP_STD_VER >= 17 1876 template <class _Tp = void> struct owner_less; 1877 #else 1878 template <class _Tp> struct owner_less; 1879 #endif 1880 1881 1882 template <class _Tp> 1883 struct _LIBCPP_TEMPLATE_VIS owner_less<shared_ptr<_Tp> > 1884 : __binary_function<shared_ptr<_Tp>, shared_ptr<_Tp>, bool> 1885 { 1886 _LIBCPP_INLINE_VISIBILITY 1887 bool operator()(shared_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT 1888 {return __x.owner_before(__y);} 1889 _LIBCPP_INLINE_VISIBILITY 1890 bool operator()(shared_ptr<_Tp> const& __x, weak_ptr<_Tp> const& __y) const _NOEXCEPT 1891 {return __x.owner_before(__y);} 1892 _LIBCPP_INLINE_VISIBILITY 1893 bool operator()( weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT 1894 {return __x.owner_before(__y);} 1895 }; 1896 1897 template <class _Tp> 1898 struct _LIBCPP_TEMPLATE_VIS owner_less<weak_ptr<_Tp> > 1899 : __binary_function<weak_ptr<_Tp>, weak_ptr<_Tp>, bool> 1900 { 1901 _LIBCPP_INLINE_VISIBILITY 1902 bool operator()( weak_ptr<_Tp> const& __x, weak_ptr<_Tp> const& __y) const _NOEXCEPT 1903 {return __x.owner_before(__y);} 1904 _LIBCPP_INLINE_VISIBILITY 1905 bool operator()(shared_ptr<_Tp> const& __x, weak_ptr<_Tp> const& __y) const _NOEXCEPT 1906 {return __x.owner_before(__y);} 1907 _LIBCPP_INLINE_VISIBILITY 1908 bool operator()( weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT 1909 {return __x.owner_before(__y);} 1910 }; 1911 1912 #if _LIBCPP_STD_VER >= 17 1913 template <> 1914 struct _LIBCPP_TEMPLATE_VIS owner_less<void> 1915 { 1916 template <class _Tp, class _Up> 1917 _LIBCPP_INLINE_VISIBILITY 1918 bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT 1919 {return __x.owner_before(__y);} 1920 template <class _Tp, class _Up> 1921 _LIBCPP_INLINE_VISIBILITY 1922 bool operator()( shared_ptr<_Tp> const& __x, weak_ptr<_Up> const& __y) const _NOEXCEPT 1923 {return __x.owner_before(__y);} 1924 template <class _Tp, class _Up> 1925 _LIBCPP_INLINE_VISIBILITY 1926 bool operator()( weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT 1927 {return __x.owner_before(__y);} 1928 template <class _Tp, class _Up> 1929 _LIBCPP_INLINE_VISIBILITY 1930 bool operator()( weak_ptr<_Tp> const& __x, weak_ptr<_Up> const& __y) const _NOEXCEPT 1931 {return __x.owner_before(__y);} 1932 typedef void is_transparent; 1933 }; 1934 #endif 1935 1936 template<class _Tp> 1937 class _LIBCPP_TEMPLATE_VIS enable_shared_from_this 1938 { 1939 mutable weak_ptr<_Tp> __weak_this_; 1940 protected: 1941 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR 1942 enable_shared_from_this() _NOEXCEPT {} 1943 _LIBCPP_INLINE_VISIBILITY 1944 enable_shared_from_this(enable_shared_from_this const&) _NOEXCEPT {} 1945 _LIBCPP_INLINE_VISIBILITY 1946 enable_shared_from_this& operator=(enable_shared_from_this const&) _NOEXCEPT 1947 {return *this;} 1948 _LIBCPP_INLINE_VISIBILITY 1949 ~enable_shared_from_this() {} 1950 public: 1951 _LIBCPP_INLINE_VISIBILITY 1952 shared_ptr<_Tp> shared_from_this() 1953 {return shared_ptr<_Tp>(__weak_this_);} 1954 _LIBCPP_INLINE_VISIBILITY 1955 shared_ptr<_Tp const> shared_from_this() const 1956 {return shared_ptr<const _Tp>(__weak_this_);} 1957 1958 #if _LIBCPP_STD_VER >= 17 1959 _LIBCPP_INLINE_VISIBILITY 1960 weak_ptr<_Tp> weak_from_this() _NOEXCEPT 1961 { return __weak_this_; } 1962 1963 _LIBCPP_INLINE_VISIBILITY 1964 weak_ptr<const _Tp> weak_from_this() const _NOEXCEPT 1965 { return __weak_this_; } 1966 #endif // _LIBCPP_STD_VER >= 17 1967 1968 template <class _Up> friend class shared_ptr; 1969 }; 1970 1971 template <class _Tp> struct _LIBCPP_TEMPLATE_VIS hash; 1972 1973 template <class _Tp> 1974 struct _LIBCPP_TEMPLATE_VIS hash<shared_ptr<_Tp> > 1975 { 1976 #if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_BINDER_TYPEDEFS) 1977 _LIBCPP_DEPRECATED_IN_CXX17 typedef shared_ptr<_Tp> argument_type; 1978 _LIBCPP_DEPRECATED_IN_CXX17 typedef size_t result_type; 1979 #endif 1980 1981 _LIBCPP_INLINE_VISIBILITY 1982 size_t operator()(const shared_ptr<_Tp>& __ptr) const _NOEXCEPT 1983 { 1984 return hash<typename shared_ptr<_Tp>::element_type*>()(__ptr.get()); 1985 } 1986 }; 1987 1988 template<class _CharT, class _Traits, class _Yp> 1989 inline _LIBCPP_INLINE_VISIBILITY 1990 basic_ostream<_CharT, _Traits>& 1991 operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p); 1992 1993 1994 #if !defined(_LIBCPP_HAS_NO_THREADS) 1995 1996 class _LIBCPP_EXPORTED_FROM_ABI __sp_mut 1997 { 1998 void* __lx_; 1999 public: 2000 void lock() _NOEXCEPT; 2001 void unlock() _NOEXCEPT; 2002 2003 private: 2004 _LIBCPP_CONSTEXPR __sp_mut(void*) _NOEXCEPT; 2005 __sp_mut(const __sp_mut&); 2006 __sp_mut& operator=(const __sp_mut&); 2007 2008 friend _LIBCPP_EXPORTED_FROM_ABI __sp_mut& __get_sp_mut(const void*); 2009 }; 2010 2011 _LIBCPP_EXPORTED_FROM_ABI _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR 2012 __sp_mut& __get_sp_mut(const void*); 2013 2014 template <class _Tp> 2015 inline _LIBCPP_INLINE_VISIBILITY 2016 bool 2017 atomic_is_lock_free(const shared_ptr<_Tp>*) 2018 { 2019 return false; 2020 } 2021 2022 template <class _Tp> 2023 _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR 2024 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> 2025 atomic_load(const shared_ptr<_Tp>* __p) 2026 { 2027 __sp_mut& __m = std::__get_sp_mut(__p); 2028 __m.lock(); 2029 shared_ptr<_Tp> __q = *__p; 2030 __m.unlock(); 2031 return __q; 2032 } 2033 2034 template <class _Tp> 2035 inline _LIBCPP_INLINE_VISIBILITY 2036 _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR 2037 shared_ptr<_Tp> 2038 atomic_load_explicit(const shared_ptr<_Tp>* __p, memory_order) 2039 { 2040 return std::atomic_load(__p); 2041 } 2042 2043 template <class _Tp> 2044 _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR 2045 _LIBCPP_HIDE_FROM_ABI void 2046 atomic_store(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r) 2047 { 2048 __sp_mut& __m = std::__get_sp_mut(__p); 2049 __m.lock(); 2050 __p->swap(__r); 2051 __m.unlock(); 2052 } 2053 2054 template <class _Tp> 2055 inline _LIBCPP_INLINE_VISIBILITY 2056 _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR 2057 void 2058 atomic_store_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order) 2059 { 2060 std::atomic_store(__p, __r); 2061 } 2062 2063 template <class _Tp> 2064 _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR 2065 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> 2066 atomic_exchange(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r) 2067 { 2068 __sp_mut& __m = std::__get_sp_mut(__p); 2069 __m.lock(); 2070 __p->swap(__r); 2071 __m.unlock(); 2072 return __r; 2073 } 2074 2075 template <class _Tp> 2076 inline _LIBCPP_INLINE_VISIBILITY 2077 _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR 2078 shared_ptr<_Tp> 2079 atomic_exchange_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order) 2080 { 2081 return std::atomic_exchange(__p, __r); 2082 } 2083 2084 template <class _Tp> 2085 _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR 2086 _LIBCPP_HIDE_FROM_ABI bool 2087 atomic_compare_exchange_strong(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w) 2088 { 2089 shared_ptr<_Tp> __temp; 2090 __sp_mut& __m = std::__get_sp_mut(__p); 2091 __m.lock(); 2092 if (__p->__owner_equivalent(*__v)) 2093 { 2094 _VSTD::swap(__temp, *__p); 2095 *__p = __w; 2096 __m.unlock(); 2097 return true; 2098 } 2099 _VSTD::swap(__temp, *__v); 2100 *__v = *__p; 2101 __m.unlock(); 2102 return false; 2103 } 2104 2105 template <class _Tp> 2106 inline _LIBCPP_INLINE_VISIBILITY 2107 _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR 2108 bool 2109 atomic_compare_exchange_weak(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w) 2110 { 2111 return std::atomic_compare_exchange_strong(__p, __v, __w); 2112 } 2113 2114 template <class _Tp> 2115 inline _LIBCPP_INLINE_VISIBILITY 2116 _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR 2117 bool 2118 atomic_compare_exchange_strong_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, 2119 shared_ptr<_Tp> __w, memory_order, memory_order) 2120 { 2121 return std::atomic_compare_exchange_strong(__p, __v, __w); 2122 } 2123 2124 template <class _Tp> 2125 inline _LIBCPP_INLINE_VISIBILITY 2126 _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR 2127 bool 2128 atomic_compare_exchange_weak_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, 2129 shared_ptr<_Tp> __w, memory_order, memory_order) 2130 { 2131 return std::atomic_compare_exchange_weak(__p, __v, __w); 2132 } 2133 2134 #endif // !defined(_LIBCPP_HAS_NO_THREADS) 2135 2136 _LIBCPP_END_NAMESPACE_STD 2137 2138 #endif // _LIBCPP___MEMORY_SHARED_PTR_H 2139