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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-exception7//8//===----------------------------------------------------------------------===//9 10#ifndef _LIBCPP___MEMORY_SHARED_PTR_H11#define _LIBCPP___MEMORY_SHARED_PTR_H12 13#include <__compare/compare_three_way.h>14#include <__compare/ordering.h>15#include <__config>16#include <__cstddef/nullptr_t.h>17#include <__cstddef/ptrdiff_t.h>18#include <__exception/exception.h>19#include <__functional/binary_function.h>20#include <__functional/operations.h>21#include <__functional/reference_wrapper.h>22#include <__fwd/ostream.h>23#include <__iterator/access.h>24#include <__memory/addressof.h>25#include <__memory/allocation_guard.h>26#include <__memory/allocator.h>27#include <__memory/allocator_destructor.h>28#include <__memory/allocator_traits.h>29#include <__memory/auto_ptr.h>30#include <__memory/compressed_pair.h>31#include <__memory/construct_at.h>32#include <__memory/destroy.h>33#include <__memory/pointer_traits.h>34#include <__memory/shared_count.h>35#include <__memory/uninitialized_algorithms.h>36#include <__memory/unique_ptr.h>37#include <__type_traits/add_reference.h>38#include <__type_traits/conditional.h>39#include <__type_traits/conjunction.h>40#include <__type_traits/disjunction.h>41#include <__type_traits/enable_if.h>42#include <__type_traits/integral_constant.h>43#include <__type_traits/is_array.h>44#include <__type_traits/is_constructible.h>45#include <__type_traits/is_convertible.h>46#include <__type_traits/is_function.h>47#include <__type_traits/is_reference.h>48#include <__type_traits/is_same.h>49#include <__type_traits/nat.h>50#include <__type_traits/negation.h>51#include <__type_traits/remove_cv.h>52#include <__type_traits/remove_extent.h>53#include <__type_traits/remove_reference.h>54#include <__utility/declval.h>55#include <__utility/exception_guard.h>56#include <__utility/forward.h>57#include <__utility/move.h>58#include <__utility/swap.h>59#include <__verbose_abort>60#include <typeinfo>61#if _LIBCPP_HAS_ATOMIC_HEADER62# include <__atomic/memory_order.h>63#endif64 65#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)66# pragma GCC system_header67#endif68 69_LIBCPP_PUSH_MACROS70#include <__undef_macros>71 72_LIBCPP_BEGIN_NAMESPACE_STD73 74class _LIBCPP_EXPORTED_FROM_ABI bad_weak_ptr : public std::exception {75public:76 _LIBCPP_HIDE_FROM_ABI bad_weak_ptr() _NOEXCEPT = default;77 _LIBCPP_HIDE_FROM_ABI bad_weak_ptr(const bad_weak_ptr&) _NOEXCEPT = default;78 _LIBCPP_HIDE_FROM_ABI bad_weak_ptr& operator=(const bad_weak_ptr&) _NOEXCEPT = default;79 ~bad_weak_ptr() _NOEXCEPT override;80 const char* what() const _NOEXCEPT override;81};82 83[[__noreturn__]] inline _LIBCPP_HIDE_FROM_ABI void __throw_bad_weak_ptr() {84#if _LIBCPP_HAS_EXCEPTIONS85 throw bad_weak_ptr();86#else87 _LIBCPP_VERBOSE_ABORT("bad_weak_ptr was thrown in -fno-exceptions mode");88#endif89}90 91template <class _Tp>92class weak_ptr;93 94template <class _Tp, class _Dp, class _Alloc>95class __shared_ptr_pointer : public __shared_weak_count {96 _LIBCPP_COMPRESSED_TRIPLE(_Tp, __ptr_, _Dp, __deleter_, _Alloc, __alloc_);97 98public:99 _LIBCPP_HIDE_FROM_ABI __shared_ptr_pointer(_Tp __p, _Dp __d, _Alloc __a)100 : __ptr_(__p), __deleter_(std::move(__d)), __alloc_(std::move(__a)) {}101 102#if _LIBCPP_HAS_RTTI103 _LIBCPP_HIDE_FROM_ABI_VIRTUAL const void* __get_deleter(const type_info&) const _NOEXCEPT override;104#endif105 106private:107 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override;108 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared_weak() _NOEXCEPT override;109};110 111#if _LIBCPP_HAS_RTTI112 113template <class _Tp, class _Dp, class _Alloc>114const void* __shared_ptr_pointer<_Tp, _Dp, _Alloc>::__get_deleter(const type_info& __t) const _NOEXCEPT {115 return __t == typeid(_Dp) ? std::addressof(__deleter_) : nullptr;116}117 118#endif // _LIBCPP_HAS_RTTI119 120template <class _Tp, class _Dp, class _Alloc>121void __shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared() _NOEXCEPT {122 __deleter_(__ptr_);123 __deleter_.~_Dp();124}125 126template <class _Tp, class _Dp, class _Alloc>127void __shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT {128 typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_pointer>::type _Al;129 typedef allocator_traits<_Al> _ATraits;130 typedef pointer_traits<typename _ATraits::pointer> _PTraits;131 132 _Al __a(__alloc_);133 __alloc_.~_Alloc();134 __a.deallocate(_PTraits::pointer_to(*this), 1);135}136 137// This tag is used to instantiate an allocator type. The various shared_ptr control blocks138// detect that the allocator has been instantiated for this type and perform alternative139// initialization/destruction based on that.140struct __for_overwrite_tag {};141 142template <class _Tp, class _Alloc>143struct __shared_ptr_emplace : __shared_weak_count {144 using __value_type _LIBCPP_NODEBUG = __remove_cv_t<_Tp>;145 146 template <class... _Args,147 class _Allocator = _Alloc,148 __enable_if_t<is_same<typename _Allocator::value_type, __for_overwrite_tag>::value, int> = 0>149 _LIBCPP_HIDE_FROM_ABI explicit __shared_ptr_emplace(_Alloc __a, _Args&&...) : __storage_(std::move(__a)) {150 static_assert(151 sizeof...(_Args) == 0, "No argument should be provided to the control block when using _for_overwrite");152 ::new (static_cast<void*>(__get_elem())) __value_type;153 }154 155 template <class... _Args,156 class _Allocator = _Alloc,157 __enable_if_t<!is_same<typename _Allocator::value_type, __for_overwrite_tag>::value, int> = 0>158 _LIBCPP_HIDE_FROM_ABI explicit __shared_ptr_emplace(_Alloc __a, _Args&&... __args) : __storage_(std::move(__a)) {159 using _TpAlloc = typename __allocator_traits_rebind<_Alloc, __value_type>::type;160 _TpAlloc __tmp(*__get_alloc());161 allocator_traits<_TpAlloc>::construct(__tmp, __get_elem(), std::forward<_Args>(__args)...);162 }163 164 _LIBCPP_HIDE_FROM_ABI _Alloc* __get_alloc() _NOEXCEPT { return __storage_.__get_alloc(); }165 166 _LIBCPP_HIDE_FROM_ABI __value_type* __get_elem() _NOEXCEPT { return __storage_.__get_elem(); }167 168private:169 template <class _Allocator = _Alloc,170 __enable_if_t<is_same<typename _Allocator::value_type, __for_overwrite_tag>::value, int> = 0>171 _LIBCPP_HIDE_FROM_ABI void __on_zero_shared_impl() _NOEXCEPT {172 __get_elem()->~__value_type();173 }174 175 template <class _Allocator = _Alloc,176 __enable_if_t<!is_same<typename _Allocator::value_type, __for_overwrite_tag>::value, int> = 0>177 _LIBCPP_HIDE_FROM_ABI void __on_zero_shared_impl() _NOEXCEPT {178 using _TpAlloc = typename __allocator_traits_rebind<_Allocator, __remove_cv_t<_Tp> >::type;179 _TpAlloc __tmp(*__get_alloc());180 allocator_traits<_TpAlloc>::destroy(__tmp, __get_elem());181 }182 183 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override { __on_zero_shared_impl(); }184 185 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared_weak() _NOEXCEPT override {186 using _ControlBlockAlloc = typename __allocator_traits_rebind<_Alloc, __shared_ptr_emplace>::type;187 using _ControlBlockPointer = typename allocator_traits<_ControlBlockAlloc>::pointer;188 _ControlBlockAlloc __tmp(*__get_alloc());189 __storage_.~_Storage();190 allocator_traits<_ControlBlockAlloc>::deallocate(__tmp, pointer_traits<_ControlBlockPointer>::pointer_to(*this), 1);191 }192 193 // TODO: It should be possible to refactor this to remove `_Storage` entirely.194 // This class implements the control block for non-array shared pointers created195 // through `std::allocate_shared` and `std::make_shared`.196 struct _Storage {197 struct _Data {198 _LIBCPP_COMPRESSED_PAIR(_Alloc, __alloc_, __value_type, __elem_);199 };200 201 _ALIGNAS_TYPE(_Data) char __buffer_[sizeof(_Data)];202 203 _LIBCPP_HIDE_FROM_ABI explicit _Storage(_Alloc&& __a) { ::new ((void*)__get_alloc()) _Alloc(std::move(__a)); }204 _LIBCPP_HIDE_FROM_ABI ~_Storage() { __get_alloc()->~_Alloc(); }205 206 _LIBCPP_HIDE_FROM_ABI _Alloc* __get_alloc() _NOEXCEPT {207 return std::addressof(reinterpret_cast<_Data*>(__buffer_)->__alloc_);208 }209 210 _LIBCPP_HIDE_FROM_ABI _LIBCPP_NO_CFI __value_type* __get_elem() _NOEXCEPT {211 return std::addressof(reinterpret_cast<_Data*>(__buffer_)->__elem_);212 }213 };214 215 _Storage __storage_;216};217 218struct __shared_ptr_dummy_rebind_allocator_type;219template <>220class allocator<__shared_ptr_dummy_rebind_allocator_type> {221public:222 template <class _Other>223 struct rebind {224 typedef allocator<_Other> other;225 };226};227 228template <class _Tp>229class enable_shared_from_this;230 231// http://eel.is/c++draft/util.sharedptr#util.smartptr.shared.general-6232// A pointer type Y* is said to be compatible with a pointer type T*233// when either Y* is convertible to T* or Y is U[N] and T is cv U[].234#if _LIBCPP_STD_VER >= 17235template <class _Yp, class _Tp>236struct __bounded_convertible_to_unbounded : false_type {};237 238template <class _Up, std::size_t _Np, class _Tp>239struct __bounded_convertible_to_unbounded<_Up[_Np], _Tp> : is_same<__remove_cv_t<_Tp>, _Up[]> {};240 241template <class _Yp, class _Tp>242struct __compatible_with : _Or< is_convertible<_Yp*, _Tp*>, __bounded_convertible_to_unbounded<_Yp, _Tp> > {};243#else244template <class _Yp, class _Tp>245struct __compatible_with : is_convertible<_Yp*, _Tp*> {};246#endif // _LIBCPP_STD_VER >= 17247 248// Constructors that take raw pointers have a different set of "compatible" constraints249// http://eel.is/c++draft/util.sharedptr#util.smartptr.shared.const-9.1250// - If T is an array type, then either T is U[N] and Y(*)[N] is convertible to T*,251// or T is U[] and Y(*)[] is convertible to T*.252// - If T is not an array type, then Y* is convertible to T*.253#if _LIBCPP_STD_VER >= 17254template <class _Yp, class _Tp, class = void>255struct __raw_pointer_compatible_with : _And< _Not<is_array<_Tp>>, is_convertible<_Yp*, _Tp*> > {};256 257template <class _Yp, class _Up, std::size_t _Np>258struct __raw_pointer_compatible_with<_Yp, _Up[_Np], __enable_if_t< is_convertible<_Yp (*)[_Np], _Up (*)[_Np]>::value> >259 : true_type {};260 261template <class _Yp, class _Up>262struct __raw_pointer_compatible_with<_Yp, _Up[], __enable_if_t< is_convertible<_Yp (*)[], _Up (*)[]>::value> >263 : true_type {};264 265#else266template <class _Yp, class _Tp>267struct __raw_pointer_compatible_with : is_convertible<_Yp*, _Tp*> {};268#endif // _LIBCPP_STD_VER >= 17269 270template <class _Ptr, class = void>271struct __is_deletable : false_type {};272template <class _Ptr>273struct __is_deletable<_Ptr, decltype(delete std::declval<_Ptr>())> : true_type {};274 275template <class _Ptr, class = void>276struct __is_array_deletable : false_type {};277template <class _Ptr>278struct __is_array_deletable<_Ptr, decltype(delete[] std::declval<_Ptr>())> : true_type {};279 280template <class _Dp, class _Pt, class = decltype(std::declval<_Dp>()(std::declval<_Pt>()))>281true_type __well_formed_deleter_test(int);282 283template <class, class>284false_type __well_formed_deleter_test(...);285 286template <class _Dp, class _Pt>287struct __well_formed_deleter : decltype(std::__well_formed_deleter_test<_Dp, _Pt>(0)) {};288 289template <class _Dp, class _Yp, class _Tp>290struct __shared_ptr_deleter_ctor_reqs {291 static const bool value = __raw_pointer_compatible_with<_Yp, _Tp>::value && is_move_constructible<_Dp>::value &&292 __well_formed_deleter<_Dp, _Yp*>::value;293};294 295template <class _Dp>296using __shared_ptr_nullptr_deleter_ctor_reqs _LIBCPP_NODEBUG =297 _And<is_move_constructible<_Dp>, __well_formed_deleter<_Dp, nullptr_t> >;298 299#if defined(_LIBCPP_ABI_ENABLE_SHARED_PTR_TRIVIAL_ABI)300# define _LIBCPP_SHARED_PTR_TRIVIAL_ABI __attribute__((__trivial_abi__))301#else302# define _LIBCPP_SHARED_PTR_TRIVIAL_ABI303#endif304 305template <class _Tp>306class _LIBCPP_SHARED_PTR_TRIVIAL_ABI shared_ptr {307 struct __nullptr_sfinae_tag {};308 309public:310#if _LIBCPP_STD_VER >= 17311 typedef weak_ptr<_Tp> weak_type;312 typedef remove_extent_t<_Tp> element_type;313#else314 typedef _Tp element_type;315#endif316 317 // A shared_ptr contains only two raw pointers which point to the heap and move constructing already doesn't require318 // any bookkeeping, so it's always trivially relocatable.319 using __trivially_relocatable _LIBCPP_NODEBUG = shared_ptr;320 321private:322 element_type* __ptr_;323 __shared_weak_count* __cntrl_;324 325public:326 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR shared_ptr() _NOEXCEPT : __ptr_(nullptr), __cntrl_(nullptr) {}327 328 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR shared_ptr(nullptr_t) _NOEXCEPT : __ptr_(nullptr), __cntrl_(nullptr) {}329 330 template <class _Yp,331 __enable_if_t< _And< __raw_pointer_compatible_with<_Yp, _Tp>332 // In C++03 we get errors when trying to do SFINAE with the333 // delete operator, so we always pretend that it's deletable.334 // The same happens on GCC.335#if !defined(_LIBCPP_CXX03_LANG) && !defined(_LIBCPP_COMPILER_GCC)336 ,337 _If<is_array<_Tp>::value, __is_array_deletable<_Yp*>, __is_deletable<_Yp*> >338#endif339 >::value,340 int> = 0>341 _LIBCPP_HIDE_FROM_ABI explicit shared_ptr(_Yp* __p) : __ptr_(__p) {342 unique_ptr<_Yp> __hold(__p);343 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;344 typedef __shared_ptr_pointer<_Yp*, __shared_ptr_default_delete<_Tp, _Yp>, _AllocT> _CntrlBlk;345 __cntrl_ = new _CntrlBlk(__p, __shared_ptr_default_delete<_Tp, _Yp>(), _AllocT());346 __hold.release();347 __enable_weak_this(__p, __p);348 }349 350 template <class _Yp, class _Dp, __enable_if_t<__shared_ptr_deleter_ctor_reqs<_Dp, _Yp, _Tp>::value, int> = 0>351 _LIBCPP_HIDE_FROM_ABI shared_ptr(_Yp* __p, _Dp __d) : __ptr_(__p) {352 auto __guard = std::__make_exception_guard([&] { __d(__p); });353 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;354 typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT> _CntrlBlk;355#ifndef _LIBCPP_CXX03_LANG356 __cntrl_ = new _CntrlBlk(__p, std::move(__d), _AllocT());357#else358 __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());359#endif // not _LIBCPP_CXX03_LANG360 __enable_weak_this(__p, __p);361 __guard.__complete();362 }363 364 template <class _Yp,365 class _Dp,366 class _Alloc,367 __enable_if_t<__shared_ptr_deleter_ctor_reqs<_Dp, _Yp, _Tp>::value, int> = 0>368 _LIBCPP_HIDE_FROM_ABI shared_ptr(_Yp* __p, _Dp __d, _Alloc __a) : __ptr_(__p) {369 auto __guard = std::__make_exception_guard([&] { __d(__p); });370 typedef __shared_ptr_pointer<_Yp*, _Dp, _Alloc> _CntrlBlk;371 typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;372 typedef __allocator_destructor<_A2> _D2;373 _A2 __a2(__a);374 unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));375 ::new ((void*)std::addressof(*__hold2.get()))376#ifndef _LIBCPP_CXX03_LANG377 _CntrlBlk(__p, std::move(__d), __a);378#else379 _CntrlBlk(__p, __d, __a);380#endif // not _LIBCPP_CXX03_LANG381 __cntrl_ = std::addressof(*__hold2.release());382 __enable_weak_this(__p, __p);383 __guard.__complete();384 }385 386 template <class _Dp>387 _LIBCPP_HIDE_FROM_ABI shared_ptr(388 nullptr_t __p,389 _Dp __d,390 __enable_if_t<__shared_ptr_nullptr_deleter_ctor_reqs<_Dp>::value, __nullptr_sfinae_tag> = __nullptr_sfinae_tag())391 : __ptr_(nullptr) {392 auto __guard = std::__make_exception_guard([&] { __d(__p); });393 typedef typename __shared_ptr_default_allocator<_Tp>::type _AllocT;394 typedef __shared_ptr_pointer<nullptr_t, _Dp, _AllocT> _CntrlBlk;395#ifndef _LIBCPP_CXX03_LANG396 __cntrl_ = new _CntrlBlk(__p, std::move(__d), _AllocT());397#else398 __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());399#endif // not _LIBCPP_CXX03_LANG400 __guard.__complete();401 }402 403 template <class _Dp, class _Alloc>404 _LIBCPP_HIDE_FROM_ABI shared_ptr(405 nullptr_t __p,406 _Dp __d,407 _Alloc __a,408 __enable_if_t<__shared_ptr_nullptr_deleter_ctor_reqs<_Dp>::value, __nullptr_sfinae_tag> = __nullptr_sfinae_tag())409 : __ptr_(nullptr) {410 auto __guard = std::__make_exception_guard([&] { __d(__p); });411 typedef __shared_ptr_pointer<nullptr_t, _Dp, _Alloc> _CntrlBlk;412 typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;413 typedef __allocator_destructor<_A2> _D2;414 _A2 __a2(__a);415 unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));416 ::new ((void*)std::addressof(*__hold2.get()))417#ifndef _LIBCPP_CXX03_LANG418 _CntrlBlk(__p, std::move(__d), __a);419#else420 _CntrlBlk(__p, __d, __a);421#endif // not _LIBCPP_CXX03_LANG422 __cntrl_ = std::addressof(*__hold2.release());423 __guard.__complete();424 }425 426 template <class _Yp>427 _LIBCPP_HIDE_FROM_ABI shared_ptr(const shared_ptr<_Yp>& __r, element_type* __p) _NOEXCEPT428 : __ptr_(__p),429 __cntrl_(__r.__cntrl_) {430 if (__cntrl_)431 __cntrl_->__add_shared();432 }433 434// LWG-2996435// We don't backport because it is an evolutionary change.436#if _LIBCPP_STD_VER >= 20437 template <class _Yp>438 _LIBCPP_HIDE_FROM_ABI shared_ptr(shared_ptr<_Yp>&& __r, element_type* __p) noexcept439 : __ptr_(__p), __cntrl_(__r.__cntrl_) {440 __r.__ptr_ = nullptr;441 __r.__cntrl_ = nullptr;442 }443#endif444 445 _LIBCPP_HIDE_FROM_ABI shared_ptr(const shared_ptr& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) {446 if (__cntrl_)447 __cntrl_->__add_shared();448 }449 450 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>451 _LIBCPP_HIDE_FROM_ABI shared_ptr(const shared_ptr<_Yp>& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) {452 if (__cntrl_)453 __cntrl_->__add_shared();454 }455 456 _LIBCPP_HIDE_FROM_ABI shared_ptr(shared_ptr&& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) {457 __r.__ptr_ = nullptr;458 __r.__cntrl_ = nullptr;459 }460 461 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>462 _LIBCPP_HIDE_FROM_ABI shared_ptr(shared_ptr<_Yp>&& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) {463 __r.__ptr_ = nullptr;464 __r.__cntrl_ = nullptr;465 }466 467 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>468 _LIBCPP_HIDE_FROM_ABI explicit shared_ptr(const weak_ptr<_Yp>& __r)469 : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_ ? __r.__cntrl_->lock() : __r.__cntrl_) {470 if (__cntrl_ == nullptr)471 std::__throw_bad_weak_ptr();472 }473 474#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)475 template <class _Yp, __enable_if_t<is_convertible<_Yp*, element_type*>::value, int> = 0>476 _LIBCPP_HIDE_FROM_ABI shared_ptr(auto_ptr<_Yp>&& __r) : __ptr_(__r.get()) {477 typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<__remove_cv_t<_Yp> > > _CntrlBlk;478 __cntrl_ = new _CntrlBlk(__r.get(), default_delete<_Yp>(), allocator<__remove_cv_t<_Yp> >());479 __enable_weak_this(__r.get(), __r.get());480 __r.release();481 }482#endif483 484 template <class _Yp,485 class _Dp,486 __enable_if_t<__compatible_with<_Yp, _Tp>::value &&487 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,488 int> = 0>489 _LIBCPP_HIDE_FROM_ABI shared_ptr(unique_ptr<_Yp, _Dp>&& __r) : __ptr_(__r.get()) {490 using _AllocT = typename __shared_ptr_default_allocator<_Yp>::type;491 using _Deleter = _If<is_lvalue_reference<_Dp>::value, reference_wrapper<__libcpp_remove_reference_t<_Dp> >, _Dp>;492 using _CntrlBlk = __shared_ptr_pointer<typename unique_ptr<_Yp, _Dp>::pointer, _Deleter, _AllocT>;493 494 __cntrl_ = __ptr_ ? new _CntrlBlk(__r.get(), std::forward<_Dp>(__r.get_deleter()), _AllocT()) : nullptr;495 __enable_weak_this(__r.get(), __r.get());496 __r.release();497 }498 499 _LIBCPP_HIDE_FROM_ABI ~shared_ptr() {500 if (__cntrl_)501 __cntrl_->__release_shared();502 }503 504 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(const shared_ptr& __r) _NOEXCEPT {505 shared_ptr(__r).swap(*this);506 return *this;507 }508 509 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>510 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT {511 shared_ptr(__r).swap(*this);512 return *this;513 }514 515 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(shared_ptr&& __r) _NOEXCEPT {516 shared_ptr(std::move(__r)).swap(*this);517 return *this;518 }519 520 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>521 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(shared_ptr<_Yp>&& __r) {522 shared_ptr(std::move(__r)).swap(*this);523 return *this;524 }525 526#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)527 template <class _Yp,528 __enable_if_t<!is_array<_Yp>::value && is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,529 int> = 0>530 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(auto_ptr<_Yp>&& __r) {531 shared_ptr(std::move(__r)).swap(*this);532 return *this;533 }534#endif535 536 template <class _Yp,537 class _Dp,538 __enable_if_t<_And< __compatible_with<_Yp, _Tp>,539 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*> >::value,540 int> = 0>541 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(unique_ptr<_Yp, _Dp>&& __r) {542 shared_ptr(std::move(__r)).swap(*this);543 return *this;544 }545 546 _LIBCPP_HIDE_FROM_ABI void swap(shared_ptr& __r) _NOEXCEPT {547 std::swap(__ptr_, __r.__ptr_);548 std::swap(__cntrl_, __r.__cntrl_);549 }550 551 _LIBCPP_HIDE_FROM_ABI void reset() _NOEXCEPT { shared_ptr().swap(*this); }552 553 template <class _Yp, __enable_if_t<__raw_pointer_compatible_with<_Yp, _Tp>::value, int> = 0>554 _LIBCPP_HIDE_FROM_ABI void reset(_Yp* __p) {555 shared_ptr(__p).swap(*this);556 }557 558 template <class _Yp, class _Dp, __enable_if_t<__shared_ptr_deleter_ctor_reqs<_Dp, _Yp, _Tp>::value, int> = 0>559 _LIBCPP_HIDE_FROM_ABI void reset(_Yp* __p, _Dp __d) {560 shared_ptr(__p, __d).swap(*this);561 }562 563 template <class _Yp,564 class _Dp,565 class _Alloc,566 __enable_if_t<__shared_ptr_deleter_ctor_reqs<_Dp, _Yp, _Tp>::value, int> = 0>567 _LIBCPP_HIDE_FROM_ABI void reset(_Yp* __p, _Dp __d, _Alloc __a) {568 shared_ptr(__p, __d, __a).swap(*this);569 }570 571 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI element_type* get() const _NOEXCEPT { return __ptr_; }572 573 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI __add_lvalue_reference_t<element_type> operator*() const _NOEXCEPT {574 return *__ptr_;575 }576 577 _LIBCPP_HIDE_FROM_ABI element_type* operator->() const _NOEXCEPT {578 static_assert(!is_array<_Tp>::value, "std::shared_ptr<T>::operator-> is only valid when T is not an array type.");579 return __ptr_;580 }581 582 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI long use_count() const _NOEXCEPT {583 return __cntrl_ ? __cntrl_->use_count() : 0;584 }585 586#if _LIBCPP_STD_VER < 20 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_SHARED_PTR_UNIQUE)587 [[__nodiscard__]] _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_HIDE_FROM_ABI bool unique() const _NOEXCEPT {588 return use_count() == 1;589 }590#endif591 592 _LIBCPP_HIDE_FROM_ABI explicit operator bool() const _NOEXCEPT { return get() != nullptr; }593 594 template <class _Up>595 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI bool owner_before(shared_ptr<_Up> const& __p) const _NOEXCEPT {596 return __cntrl_ < __p.__cntrl_;597 }598 599 template <class _Up>600 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI bool owner_before(weak_ptr<_Up> const& __p) const _NOEXCEPT {601 return __cntrl_ < __p.__cntrl_;602 }603 604 _LIBCPP_HIDE_FROM_ABI bool __owner_equivalent(const shared_ptr& __p) const { return __cntrl_ == __p.__cntrl_; }605 606#if _LIBCPP_STD_VER >= 17607 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI __add_lvalue_reference_t<element_type> operator[](ptrdiff_t __i) const {608 static_assert(is_array<_Tp>::value, "std::shared_ptr<T>::operator[] is only valid when T is an array type.");609 return __ptr_[__i];610 }611#endif612 613#if _LIBCPP_HAS_RTTI614 template <class _Dp>615 _LIBCPP_HIDE_FROM_ABI _Dp* __get_deleter() const _NOEXCEPT {616 return static_cast<_Dp*>(__cntrl_ ? const_cast<void*>(__cntrl_->__get_deleter(typeid(_Dp))) : nullptr);617 }618#endif // _LIBCPP_HAS_RTTI619 620 template <class _Yp, class _CntrlBlk>621 _LIBCPP_HIDE_FROM_ABI static shared_ptr<_Tp> __create_with_control_block(_Yp* __p, _CntrlBlk* __cntrl) _NOEXCEPT {622 shared_ptr<_Tp> __r;623 __r.__ptr_ = __p;624 __r.__cntrl_ = __cntrl;625 __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);626 return __r;627 }628 629private:630 template <class _Yp, bool = is_function<_Yp>::value>631 struct __shared_ptr_default_allocator {632 typedef allocator<__remove_cv_t<_Yp> > type;633 };634 635 template <class _Yp>636 struct __shared_ptr_default_allocator<_Yp, true> {637 typedef allocator<__shared_ptr_dummy_rebind_allocator_type> type;638 };639 640 template <class _Yp,641 class _OrigPtr,642 __enable_if_t<is_convertible<_OrigPtr*, const enable_shared_from_this<_Yp>*>::value, int> = 0>643 _LIBCPP_HIDE_FROM_ABI void __enable_weak_this(const enable_shared_from_this<_Yp>* __e, _OrigPtr* __ptr) _NOEXCEPT {644 typedef __remove_cv_t<_Yp> _RawYp;645 if (__e && __e->__weak_this_.expired()) {646 __e->__weak_this_ = shared_ptr<_RawYp>(*this, const_cast<_RawYp*>(static_cast<const _Yp*>(__ptr)));647 }648 }649 650 _LIBCPP_HIDE_FROM_ABI void __enable_weak_this(...) _NOEXCEPT {}651 652 template <class, class _Yp>653 struct __shared_ptr_default_delete : default_delete<_Yp> {};654 655 template <class _Yp, class _Un, size_t _Sz>656 struct __shared_ptr_default_delete<_Yp[_Sz], _Un> : default_delete<_Yp[]> {};657 658 template <class _Yp, class _Un>659 struct __shared_ptr_default_delete<_Yp[], _Un> : default_delete<_Yp[]> {};660 661 template <class _Up>662 friend class shared_ptr;663 template <class _Up>664 friend class weak_ptr;665};666 667#if _LIBCPP_STD_VER >= 17668template <class _Tp>669shared_ptr(weak_ptr<_Tp>) -> shared_ptr<_Tp>;670template <class _Tp, class _Dp>671shared_ptr(unique_ptr<_Tp, _Dp>) -> shared_ptr<_Tp>;672#endif673 674//675// std::allocate_shared and std::make_shared676//677template <class _Tp, class _Alloc, class... _Args, __enable_if_t<!is_array<_Tp>::value, int> = 0>678[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> allocate_shared(const _Alloc& __a, _Args&&... __args) {679 using _ControlBlock = __shared_ptr_emplace<_Tp, _Alloc>;680 using _ControlBlockAllocator = typename __allocator_traits_rebind<_Alloc, _ControlBlock>::type;681 __allocation_guard<_ControlBlockAllocator> __guard(__a, 1);682 ::new ((void*)std::addressof(*__guard.__get())) _ControlBlock(__a, std::forward<_Args>(__args)...);683 auto __control_block = __guard.__release_ptr();684 return shared_ptr<_Tp>::__create_with_control_block(685 (*__control_block).__get_elem(), std::addressof(*__control_block));686}687 688template <class _Tp, class... _Args, __enable_if_t<!is_array<_Tp>::value, int> = 0>689[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> make_shared(_Args&&... __args) {690 return std::allocate_shared<_Tp>(allocator<__remove_cv_t<_Tp> >(), std::forward<_Args>(__args)...);691}692 693#if _LIBCPP_STD_VER >= 20694 695template <class _Tp, class _Alloc, __enable_if_t<!is_array<_Tp>::value, int> = 0>696[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> allocate_shared_for_overwrite(const _Alloc& __a) {697 using _ForOverwriteAllocator = __allocator_traits_rebind_t<_Alloc, __for_overwrite_tag>;698 _ForOverwriteAllocator __alloc(__a);699 return std::allocate_shared<_Tp>(__alloc);700}701 702template <class _Tp, __enable_if_t<!is_array<_Tp>::value, int> = 0>703[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> make_shared_for_overwrite() {704 return std::allocate_shared_for_overwrite<_Tp>(allocator<__remove_cv_t<_Tp>>());705}706 707#endif // _LIBCPP_STD_VER >= 20708 709#if _LIBCPP_STD_VER >= 17710 711template <size_t _Alignment>712struct __sp_aligned_storage {713 alignas(_Alignment) char __storage[_Alignment];714};715 716template <class _Tp, class _Alloc>717struct __unbounded_array_control_block;718 719template <class _Tp, class _Alloc>720struct __unbounded_array_control_block<_Tp[], _Alloc> : __shared_weak_count {721 _LIBCPP_HIDE_FROM_ABI constexpr _Tp* __get_data() noexcept { return __data_; }722 723 _LIBCPP_HIDE_FROM_ABI explicit __unbounded_array_control_block(724 _Alloc const& __alloc, size_t __count, _Tp const& __arg)725 : __alloc_(__alloc), __count_(__count) {726 std::__uninitialized_allocator_fill_n_multidimensional(__alloc_, std::begin(__data_), __count_, __arg);727 }728 729 _LIBCPP_HIDE_FROM_ABI explicit __unbounded_array_control_block(_Alloc const& __alloc, size_t __count)730 : __alloc_(__alloc), __count_(__count) {731# if _LIBCPP_STD_VER >= 20732 if constexpr (is_same_v<typename _Alloc::value_type, __for_overwrite_tag>) {733 // We are purposefully not using an allocator-aware default construction because the spec says so.734 // There's currently no way of expressing default initialization in an allocator-aware manner anyway.735 std::uninitialized_default_construct_n(std::begin(__data_), __count_);736 } else {737 std::__uninitialized_allocator_value_construct_n_multidimensional(__alloc_, std::begin(__data_), __count_);738 }739# else740 std::__uninitialized_allocator_value_construct_n_multidimensional(__alloc_, std::begin(__data_), __count_);741# endif742 }743 744 // Returns the number of bytes required to store a control block followed by the given number745 // of elements of _Tp, with the whole storage being aligned to a multiple of _Tp's alignment.746 _LIBCPP_HIDE_FROM_ABI static constexpr size_t __bytes_for(size_t __elements) {747 // When there's 0 elements, the control block alone is enough since it holds one element.748 // Otherwise, we allocate one fewer element than requested because the control block already749 // holds one. Also, we use the bitwise formula below to ensure that we allocate enough bytes750 // for the whole allocation to be a multiple of _Tp's alignment. That formula is taken from [1].751 //752 // [1]: https://en.wikipedia.org/wiki/Data_structure_alignment#Computing_padding753 size_t __bytes = __elements == 0 ? sizeof(__unbounded_array_control_block)754 : (__elements - 1) * sizeof(_Tp) + sizeof(__unbounded_array_control_block);755 constexpr size_t __align = alignof(_Tp);756 return (__bytes + __align - 1) & ~(__align - 1);757 }758 759 _LIBCPP_HIDE_FROM_ABI_VIRTUAL760 ~__unbounded_array_control_block() override {761 } // can't be `= default` because of the sometimes-non-trivial union member __data_762 763private:764 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override {765# if _LIBCPP_STD_VER >= 20766 if constexpr (is_same_v<typename _Alloc::value_type, __for_overwrite_tag>) {767 std::__reverse_destroy(__data_, __data_ + __count_);768 } else {769 __allocator_traits_rebind_t<_Alloc, _Tp> __value_alloc(__alloc_);770 std::__allocator_destroy_multidimensional(__value_alloc, __data_, __data_ + __count_);771 }772# else773 __allocator_traits_rebind_t<_Alloc, _Tp> __value_alloc(__alloc_);774 std::__allocator_destroy_multidimensional(__value_alloc, __data_, __data_ + __count_);775# endif776 }777 778 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared_weak() _NOEXCEPT override {779 using _AlignedStorage = __sp_aligned_storage<alignof(__unbounded_array_control_block)>;780 using _StorageAlloc = __allocator_traits_rebind_t<_Alloc, _AlignedStorage>;781 using _PointerTraits = pointer_traits<typename allocator_traits<_StorageAlloc>::pointer>;782 783 _StorageAlloc __tmp(__alloc_);784 __alloc_.~_Alloc();785 size_t __size = __unbounded_array_control_block::__bytes_for(__count_);786 _AlignedStorage* __storage = reinterpret_cast<_AlignedStorage*>(this);787 allocator_traits<_StorageAlloc>::deallocate(788 __tmp, _PointerTraits::pointer_to(*__storage), __size / sizeof(_AlignedStorage));789 }790 791 _LIBCPP_NO_UNIQUE_ADDRESS _Alloc __alloc_;792 size_t __count_;793 union {794 _Tp __data_[1];795 };796};797 798template <class _Array, class _Alloc, class... _Arg>799_LIBCPP_HIDE_FROM_ABI shared_ptr<_Array>800__allocate_shared_unbounded_array(const _Alloc& __a, size_t __n, _Arg&&... __arg) {801 static_assert(__is_unbounded_array_v<_Array>);802 // We compute the number of bytes necessary to hold the control block and the803 // array elements. Then, we allocate an array of properly-aligned dummy structs804 // large enough to hold the control block and array. This allows shifting the805 // burden of aligning memory properly from us to the allocator.806 using _ControlBlock = __unbounded_array_control_block<_Array, _Alloc>;807 using _AlignedStorage = __sp_aligned_storage<alignof(_ControlBlock)>;808 using _StorageAlloc = __allocator_traits_rebind_t<_Alloc, _AlignedStorage>;809 __allocation_guard<_StorageAlloc> __guard(__a, _ControlBlock::__bytes_for(__n) / sizeof(_AlignedStorage));810 _ControlBlock* __control_block = reinterpret_cast<_ControlBlock*>(std::addressof(*__guard.__get()));811 std::__construct_at(__control_block, __a, __n, std::forward<_Arg>(__arg)...);812 __guard.__release_ptr();813 return shared_ptr<_Array>::__create_with_control_block(__control_block->__get_data(), __control_block);814}815 816template <class _Tp, class _Alloc>817struct __bounded_array_control_block;818 819template <class _Tp, size_t _Count, class _Alloc>820struct __bounded_array_control_block<_Tp[_Count], _Alloc> : __shared_weak_count {821 _LIBCPP_HIDE_FROM_ABI constexpr _Tp* __get_data() noexcept { return __data_; }822 823 _LIBCPP_HIDE_FROM_ABI explicit __bounded_array_control_block(_Alloc const& __alloc, _Tp const& __arg)824 : __alloc_(__alloc) {825 std::__uninitialized_allocator_fill_n_multidimensional(__alloc_, std::addressof(__data_[0]), _Count, __arg);826 }827 828 _LIBCPP_HIDE_FROM_ABI explicit __bounded_array_control_block(_Alloc const& __alloc) : __alloc_(__alloc) {829# if _LIBCPP_STD_VER >= 20830 if constexpr (is_same_v<typename _Alloc::value_type, __for_overwrite_tag>) {831 // We are purposefully not using an allocator-aware default construction because the spec says so.832 // There's currently no way of expressing default initialization in an allocator-aware manner anyway.833 std::uninitialized_default_construct_n(std::addressof(__data_[0]), _Count);834 } else {835 std::__uninitialized_allocator_value_construct_n_multidimensional(__alloc_, std::addressof(__data_[0]), _Count);836 }837# else838 std::__uninitialized_allocator_value_construct_n_multidimensional(__alloc_, std::addressof(__data_[0]), _Count);839# endif840 }841 842 _LIBCPP_HIDE_FROM_ABI_VIRTUAL843 ~__bounded_array_control_block() override {844 } // can't be `= default` because of the sometimes-non-trivial union member __data_845 846private:847 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override {848# if _LIBCPP_STD_VER >= 20849 if constexpr (is_same_v<typename _Alloc::value_type, __for_overwrite_tag>) {850 std::__reverse_destroy(__data_, __data_ + _Count);851 } else {852 __allocator_traits_rebind_t<_Alloc, _Tp> __value_alloc(__alloc_);853 std::__allocator_destroy_multidimensional(__value_alloc, __data_, __data_ + _Count);854 }855# else856 __allocator_traits_rebind_t<_Alloc, _Tp> __value_alloc(__alloc_);857 std::__allocator_destroy_multidimensional(__value_alloc, __data_, __data_ + _Count);858# endif859 }860 861 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared_weak() _NOEXCEPT override {862 using _ControlBlockAlloc = __allocator_traits_rebind_t<_Alloc, __bounded_array_control_block>;863 using _PointerTraits = pointer_traits<typename allocator_traits<_ControlBlockAlloc>::pointer>;864 865 _ControlBlockAlloc __tmp(__alloc_);866 __alloc_.~_Alloc();867 allocator_traits<_ControlBlockAlloc>::deallocate(__tmp, _PointerTraits::pointer_to(*this), 1);868 }869 870 _LIBCPP_NO_UNIQUE_ADDRESS _Alloc __alloc_;871 union {872 _Tp __data_[_Count];873 };874};875 876template <class _Array, class _Alloc, class... _Arg>877_LIBCPP_HIDE_FROM_ABI shared_ptr<_Array> __allocate_shared_bounded_array(const _Alloc& __a, _Arg&&... __arg) {878 static_assert(__is_bounded_array_v<_Array>);879 using _ControlBlock = __bounded_array_control_block<_Array, _Alloc>;880 using _ControlBlockAlloc = __allocator_traits_rebind_t<_Alloc, _ControlBlock>;881 882 __allocation_guard<_ControlBlockAlloc> __guard(__a, 1);883 _ControlBlock* __control_block = reinterpret_cast<_ControlBlock*>(std::addressof(*__guard.__get()));884 std::__construct_at(__control_block, __a, std::forward<_Arg>(__arg)...);885 __guard.__release_ptr();886 return shared_ptr<_Array>::__create_with_control_block(__control_block->__get_data(), __control_block);887}888 889#endif // _LIBCPP_STD_VER >= 17890 891#if _LIBCPP_STD_VER >= 20892 893// bounded array variants894template <class _Tp, class _Alloc, __enable_if_t<is_bounded_array<_Tp>::value, int> = 0>895[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> allocate_shared(const _Alloc& __a) {896 return std::__allocate_shared_bounded_array<_Tp>(__a);897}898 899template <class _Tp, class _Alloc, __enable_if_t<is_bounded_array<_Tp>::value, int> = 0>900[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>901allocate_shared(const _Alloc& __a, const remove_extent_t<_Tp>& __u) {902 return std::__allocate_shared_bounded_array<_Tp>(__a, __u);903}904 905template <class _Tp, class _Alloc, __enable_if_t<is_bounded_array<_Tp>::value, int> = 0>906[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> allocate_shared_for_overwrite(const _Alloc& __a) {907 using _ForOverwriteAllocator = __allocator_traits_rebind_t<_Alloc, __for_overwrite_tag>;908 _ForOverwriteAllocator __alloc(__a);909 return std::__allocate_shared_bounded_array<_Tp>(__alloc);910}911 912template <class _Tp, __enable_if_t<is_bounded_array<_Tp>::value, int> = 0>913[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> make_shared() {914 return std::__allocate_shared_bounded_array<_Tp>(allocator<_Tp>());915}916 917template <class _Tp, __enable_if_t<is_bounded_array<_Tp>::value, int> = 0>918[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> make_shared(const remove_extent_t<_Tp>& __u) {919 return std::__allocate_shared_bounded_array<_Tp>(allocator<_Tp>(), __u);920}921 922template <class _Tp, __enable_if_t<is_bounded_array<_Tp>::value, int> = 0>923[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> make_shared_for_overwrite() {924 return std::__allocate_shared_bounded_array<_Tp>(allocator<__for_overwrite_tag>());925}926 927// unbounded array variants928template <class _Tp, class _Alloc, __enable_if_t<is_unbounded_array<_Tp>::value, int> = 0>929[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> allocate_shared(const _Alloc& __a, size_t __n) {930 return std::__allocate_shared_unbounded_array<_Tp>(__a, __n);931}932 933template <class _Tp, class _Alloc, __enable_if_t<is_unbounded_array<_Tp>::value, int> = 0>934[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>935allocate_shared(const _Alloc& __a, size_t __n, const remove_extent_t<_Tp>& __u) {936 return std::__allocate_shared_unbounded_array<_Tp>(__a, __n, __u);937}938 939template <class _Tp, class _Alloc, __enable_if_t<is_unbounded_array<_Tp>::value, int> = 0>940[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> allocate_shared_for_overwrite(const _Alloc& __a, size_t __n) {941 using _ForOverwriteAllocator = __allocator_traits_rebind_t<_Alloc, __for_overwrite_tag>;942 _ForOverwriteAllocator __alloc(__a);943 return std::__allocate_shared_unbounded_array<_Tp>(__alloc, __n);944}945 946template <class _Tp, __enable_if_t<is_unbounded_array<_Tp>::value, int> = 0>947[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> make_shared(size_t __n) {948 return std::__allocate_shared_unbounded_array<_Tp>(allocator<_Tp>(), __n);949}950 951template <class _Tp, __enable_if_t<is_unbounded_array<_Tp>::value, int> = 0>952[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> make_shared(size_t __n, const remove_extent_t<_Tp>& __u) {953 return std::__allocate_shared_unbounded_array<_Tp>(allocator<_Tp>(), __n, __u);954}955 956template <class _Tp, __enable_if_t<is_unbounded_array<_Tp>::value, int> = 0>957[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> make_shared_for_overwrite(size_t __n) {958 return std::__allocate_shared_unbounded_array<_Tp>(allocator<__for_overwrite_tag>(), __n);959}960 961#endif // _LIBCPP_STD_VER >= 20962 963template <class _Tp, class _Up>964inline _LIBCPP_HIDE_FROM_ABI bool operator==(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT {965 return __x.get() == __y.get();966}967 968#if _LIBCPP_STD_VER <= 17969 970template <class _Tp, class _Up>971inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT {972 return !(__x == __y);973}974 975template <class _Tp, class _Up>976inline _LIBCPP_HIDE_FROM_ABI bool operator<(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT {977# if _LIBCPP_STD_VER <= 11978 typedef typename common_type<_Tp*, _Up*>::type _Vp;979 return less<_Vp>()(__x.get(), __y.get());980# else981 return less<>()(__x.get(), __y.get());982# endif983}984 985template <class _Tp, class _Up>986inline _LIBCPP_HIDE_FROM_ABI bool operator>(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT {987 return __y < __x;988}989 990template <class _Tp, class _Up>991inline _LIBCPP_HIDE_FROM_ABI bool operator<=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT {992 return !(__y < __x);993}994 995template <class _Tp, class _Up>996inline _LIBCPP_HIDE_FROM_ABI bool operator>=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT {997 return !(__x < __y);998}999 1000#endif // _LIBCPP_STD_VER <= 171001 1002#if _LIBCPP_STD_VER >= 201003template <class _Tp, class _Up>1004_LIBCPP_HIDE_FROM_ABI strong_ordering operator<=>(shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) noexcept {1005 return compare_three_way()(__x.get(), __y.get());1006}1007#endif1008 1009template <class _Tp>1010inline _LIBCPP_HIDE_FROM_ABI bool operator==(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT {1011 return !__x;1012}1013 1014#if _LIBCPP_STD_VER <= 171015 1016template <class _Tp>1017inline _LIBCPP_HIDE_FROM_ABI bool operator==(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT {1018 return !__x;1019}1020 1021template <class _Tp>1022inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT {1023 return static_cast<bool>(__x);1024}1025 1026template <class _Tp>1027inline _LIBCPP_HIDE_FROM_ABI bool operator!=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT {1028 return static_cast<bool>(__x);1029}1030 1031template <class _Tp>1032inline _LIBCPP_HIDE_FROM_ABI bool operator<(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT {1033 return less<typename shared_ptr<_Tp>::element_type*>()(__x.get(), nullptr);1034}1035 1036template <class _Tp>1037inline _LIBCPP_HIDE_FROM_ABI bool operator<(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT {1038 return less<typename shared_ptr<_Tp>::element_type*>()(nullptr, __x.get());1039}1040 1041template <class _Tp>1042inline _LIBCPP_HIDE_FROM_ABI bool operator>(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT {1043 return nullptr < __x;1044}1045 1046template <class _Tp>1047inline _LIBCPP_HIDE_FROM_ABI bool operator>(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT {1048 return __x < nullptr;1049}1050 1051template <class _Tp>1052inline _LIBCPP_HIDE_FROM_ABI bool operator<=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT {1053 return !(nullptr < __x);1054}1055 1056template <class _Tp>1057inline _LIBCPP_HIDE_FROM_ABI bool operator<=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT {1058 return !(__x < nullptr);1059}1060 1061template <class _Tp>1062inline _LIBCPP_HIDE_FROM_ABI bool operator>=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT {1063 return !(__x < nullptr);1064}1065 1066template <class _Tp>1067inline _LIBCPP_HIDE_FROM_ABI bool operator>=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT {1068 return !(nullptr < __x);1069}1070 1071#endif // _LIBCPP_STD_VER <= 171072 1073#if _LIBCPP_STD_VER >= 201074template <class _Tp>1075_LIBCPP_HIDE_FROM_ABI strong_ordering operator<=>(shared_ptr<_Tp> const& __x, nullptr_t) noexcept {1076 return compare_three_way()(__x.get(), static_cast<typename shared_ptr<_Tp>::element_type*>(nullptr));1077}1078#endif1079 1080template <class _Tp>1081inline _LIBCPP_HIDE_FROM_ABI void swap(shared_ptr<_Tp>& __x, shared_ptr<_Tp>& __y) _NOEXCEPT {1082 __x.swap(__y);1083}1084 1085template <class _Tp, class _Up>1086[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>1087static_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT {1088 return shared_ptr<_Tp>(__r, static_cast< typename shared_ptr<_Tp>::element_type*>(__r.get()));1089}1090 1091// LWG-29961092// We don't backport because it is an evolutionary change.1093#if _LIBCPP_STD_VER >= 201094template <class _Tp, class _Up>1095[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> static_pointer_cast(shared_ptr<_Up>&& __r) noexcept {1096 return shared_ptr<_Tp>(std::move(__r), static_cast<typename shared_ptr<_Tp>::element_type*>(__r.get()));1097}1098#endif1099 1100template <class _Tp, class _Up>1101[[__nodiscard__]] inline1102 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> dynamic_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT {1103 typedef typename shared_ptr<_Tp>::element_type _ET;1104 _ET* __p = dynamic_cast<_ET*>(__r.get());1105 return __p ? shared_ptr<_Tp>(__r, __p) : shared_ptr<_Tp>();1106}1107 1108// LWG-29961109// We don't backport because it is an evolutionary change.1110#if _LIBCPP_STD_VER >= 201111template <class _Tp, class _Up>1112[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> dynamic_pointer_cast(shared_ptr<_Up>&& __r) noexcept {1113 auto* __p = dynamic_cast<typename shared_ptr<_Tp>::element_type*>(__r.get());1114 return __p ? shared_ptr<_Tp>(std::move(__r), __p) : shared_ptr<_Tp>();1115}1116#endif1117 1118template <class _Tp, class _Up>1119[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> const_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT {1120 typedef typename shared_ptr<_Tp>::element_type _RTp;1121 return shared_ptr<_Tp>(__r, const_cast<_RTp*>(__r.get()));1122}1123 1124// LWG-29961125// We don't backport because it is an evolutionary change.1126#if _LIBCPP_STD_VER >= 201127template <class _Tp, class _Up>1128[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> const_pointer_cast(shared_ptr<_Up>&& __r) noexcept {1129 return shared_ptr<_Tp>(std::move(__r), const_cast<typename shared_ptr<_Tp>::element_type*>(__r.get()));1130}1131#endif1132 1133template <class _Tp, class _Up>1134[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> reinterpret_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT {1135 return shared_ptr<_Tp>(__r, reinterpret_cast< typename shared_ptr<_Tp>::element_type*>(__r.get()));1136}1137 1138// LWG-29961139// We don't backport because it is an evolutionary change.1140#if _LIBCPP_STD_VER >= 201141template <class _Tp, class _Up>1142[[nodiscard]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> reinterpret_pointer_cast(shared_ptr<_Up>&& __r) noexcept {1143 return shared_ptr<_Tp>(std::move(__r), reinterpret_cast<typename shared_ptr<_Tp>::element_type*>(__r.get()));1144}1145#endif1146 1147#if _LIBCPP_HAS_RTTI1148 1149template <class _Dp, class _Tp>1150[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _Dp* get_deleter(const shared_ptr<_Tp>& __p) _NOEXCEPT {1151 return __p.template __get_deleter<_Dp>();1152}1153 1154#endif // _LIBCPP_HAS_RTTI1155 1156template <class _Tp>1157class _LIBCPP_SHARED_PTR_TRIVIAL_ABI weak_ptr {1158public:1159#if _LIBCPP_STD_VER >= 171160 typedef remove_extent_t<_Tp> element_type;1161#else1162 typedef _Tp element_type;1163#endif1164 1165 // A weak_ptr contains only two raw pointers which point to the heap and move constructing already doesn't require1166 // any bookkeeping, so it's always trivially relocatable.1167 using __trivially_relocatable _LIBCPP_NODEBUG = weak_ptr;1168 1169private:1170 element_type* __ptr_;1171 __shared_weak_count* __cntrl_;1172 1173public:1174 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR weak_ptr() _NOEXCEPT;1175 1176 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>1177 _LIBCPP_HIDE_FROM_ABI weak_ptr(shared_ptr<_Yp> const& __r) _NOEXCEPT;1178 1179 _LIBCPP_HIDE_FROM_ABI weak_ptr(weak_ptr const& __r) _NOEXCEPT;1180 1181 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>1182 _LIBCPP_HIDE_FROM_ABI weak_ptr(weak_ptr<_Yp> const& __r) _NOEXCEPT;1183 1184 _LIBCPP_HIDE_FROM_ABI weak_ptr(weak_ptr&& __r) _NOEXCEPT;1185 1186 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>1187 _LIBCPP_HIDE_FROM_ABI weak_ptr(weak_ptr<_Yp>&& __r) _NOEXCEPT;1188 1189 _LIBCPP_HIDE_FROM_ABI ~weak_ptr();1190 1191 _LIBCPP_HIDE_FROM_ABI weak_ptr& operator=(weak_ptr const& __r) _NOEXCEPT;1192 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>1193 _LIBCPP_HIDE_FROM_ABI weak_ptr& operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT;1194 1195 _LIBCPP_HIDE_FROM_ABI weak_ptr& operator=(weak_ptr&& __r) _NOEXCEPT;1196 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>1197 _LIBCPP_HIDE_FROM_ABI weak_ptr& operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT;1198 1199 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>1200 _LIBCPP_HIDE_FROM_ABI weak_ptr& operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT;1201 1202 _LIBCPP_HIDE_FROM_ABI void swap(weak_ptr& __r) _NOEXCEPT;1203 _LIBCPP_HIDE_FROM_ABI void reset() _NOEXCEPT;1204 1205 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI long use_count() const _NOEXCEPT {1206 return __cntrl_ ? __cntrl_->use_count() : 0;1207 }1208 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI bool expired() const _NOEXCEPT {1209 return __cntrl_ == nullptr || __cntrl_->use_count() == 0;1210 }1211 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> lock() const _NOEXCEPT;1212 template <class _Up>1213 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI bool owner_before(const shared_ptr<_Up>& __r) const _NOEXCEPT {1214 return __cntrl_ < __r.__cntrl_;1215 }1216 template <class _Up>1217 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI bool owner_before(const weak_ptr<_Up>& __r) const _NOEXCEPT {1218 return __cntrl_ < __r.__cntrl_;1219 }1220 1221 template <class _Up>1222 friend class weak_ptr;1223 template <class _Up>1224 friend class shared_ptr;1225};1226 1227#if _LIBCPP_STD_VER >= 171228template <class _Tp>1229weak_ptr(shared_ptr<_Tp>) -> weak_ptr<_Tp>;1230#endif1231 1232template <class _Tp>1233inline _LIBCPP_CONSTEXPR weak_ptr<_Tp>::weak_ptr() _NOEXCEPT : __ptr_(nullptr), __cntrl_(nullptr) {}1234 1235template <class _Tp>1236inline weak_ptr<_Tp>::weak_ptr(weak_ptr const& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) {1237 if (__cntrl_)1238 __cntrl_->__add_weak();1239}1240 1241template <class _Tp>1242template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> >1243inline weak_ptr<_Tp>::weak_ptr(shared_ptr<_Yp> const& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) {1244 if (__cntrl_)1245 __cntrl_->__add_weak();1246}1247 1248template <class _Tp>1249template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> >1250inline weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp> const& __r) _NOEXCEPT : __ptr_(nullptr), __cntrl_(nullptr) {1251 shared_ptr<_Yp> __s = __r.lock();1252 *this = weak_ptr<_Tp>(__s);1253}1254 1255template <class _Tp>1256inline weak_ptr<_Tp>::weak_ptr(weak_ptr&& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) {1257 __r.__ptr_ = nullptr;1258 __r.__cntrl_ = nullptr;1259}1260 1261template <class _Tp>1262template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> >1263inline weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp>&& __r) _NOEXCEPT : __ptr_(nullptr), __cntrl_(nullptr) {1264 shared_ptr<_Yp> __s = __r.lock();1265 *this = weak_ptr<_Tp>(__s);1266 __r.reset();1267}1268 1269template <class _Tp>1270weak_ptr<_Tp>::~weak_ptr() {1271 if (__cntrl_)1272 __cntrl_->__release_weak();1273}1274 1275template <class _Tp>1276inline weak_ptr<_Tp>& weak_ptr<_Tp>::operator=(weak_ptr const& __r) _NOEXCEPT {1277 weak_ptr(__r).swap(*this);1278 return *this;1279}1280 1281template <class _Tp>1282template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> >1283inline weak_ptr<_Tp>& weak_ptr<_Tp>::operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT {1284 weak_ptr(__r).swap(*this);1285 return *this;1286}1287 1288template <class _Tp>1289inline weak_ptr<_Tp>& weak_ptr<_Tp>::operator=(weak_ptr&& __r) _NOEXCEPT {1290 weak_ptr(std::move(__r)).swap(*this);1291 return *this;1292}1293 1294template <class _Tp>1295template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> >1296inline weak_ptr<_Tp>& weak_ptr<_Tp>::operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT {1297 weak_ptr(std::move(__r)).swap(*this);1298 return *this;1299}1300 1301template <class _Tp>1302template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> >1303inline weak_ptr<_Tp>& weak_ptr<_Tp>::operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT {1304 weak_ptr(__r).swap(*this);1305 return *this;1306}1307 1308template <class _Tp>1309inline void weak_ptr<_Tp>::swap(weak_ptr& __r) _NOEXCEPT {1310 std::swap(__ptr_, __r.__ptr_);1311 std::swap(__cntrl_, __r.__cntrl_);1312}1313 1314template <class _Tp>1315inline _LIBCPP_HIDE_FROM_ABI void swap(weak_ptr<_Tp>& __x, weak_ptr<_Tp>& __y) _NOEXCEPT {1316 __x.swap(__y);1317}1318 1319template <class _Tp>1320inline void weak_ptr<_Tp>::reset() _NOEXCEPT {1321 weak_ptr().swap(*this);1322}1323 1324template <class _Tp>1325shared_ptr<_Tp> weak_ptr<_Tp>::lock() const _NOEXCEPT {1326 shared_ptr<_Tp> __r;1327 __r.__cntrl_ = __cntrl_ ? __cntrl_->lock() : __cntrl_;1328 if (__r.__cntrl_)1329 __r.__ptr_ = __ptr_;1330 return __r;1331}1332 1333#if _LIBCPP_STD_VER >= 171334template <class _Tp = void>1335struct owner_less;1336#else1337template <class _Tp>1338struct owner_less;1339#endif1340 1341template <class _Tp>1342struct owner_less<shared_ptr<_Tp> > : __binary_function<shared_ptr<_Tp>, shared_ptr<_Tp>, bool> {1343 _LIBCPP_HIDE_FROM_ABI bool operator()(shared_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT {1344 return __x.owner_before(__y);1345 }1346 _LIBCPP_HIDE_FROM_ABI bool operator()(shared_ptr<_Tp> const& __x, weak_ptr<_Tp> const& __y) const _NOEXCEPT {1347 return __x.owner_before(__y);1348 }1349 _LIBCPP_HIDE_FROM_ABI bool operator()(weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT {1350 return __x.owner_before(__y);1351 }1352};1353 1354template <class _Tp>1355struct owner_less<weak_ptr<_Tp> > : __binary_function<weak_ptr<_Tp>, weak_ptr<_Tp>, bool> {1356 _LIBCPP_HIDE_FROM_ABI bool operator()(weak_ptr<_Tp> const& __x, weak_ptr<_Tp> const& __y) const _NOEXCEPT {1357 return __x.owner_before(__y);1358 }1359 _LIBCPP_HIDE_FROM_ABI bool operator()(shared_ptr<_Tp> const& __x, weak_ptr<_Tp> const& __y) const _NOEXCEPT {1360 return __x.owner_before(__y);1361 }1362 _LIBCPP_HIDE_FROM_ABI bool operator()(weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT {1363 return __x.owner_before(__y);1364 }1365};1366 1367#if _LIBCPP_STD_VER >= 171368template <>1369struct owner_less<void> {1370 template <class _Tp, class _Up>1371 _LIBCPP_HIDE_FROM_ABI bool operator()(shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT {1372 return __x.owner_before(__y);1373 }1374 template <class _Tp, class _Up>1375 _LIBCPP_HIDE_FROM_ABI bool operator()(shared_ptr<_Tp> const& __x, weak_ptr<_Up> const& __y) const _NOEXCEPT {1376 return __x.owner_before(__y);1377 }1378 template <class _Tp, class _Up>1379 _LIBCPP_HIDE_FROM_ABI bool operator()(weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT {1380 return __x.owner_before(__y);1381 }1382 template <class _Tp, class _Up>1383 _LIBCPP_HIDE_FROM_ABI bool operator()(weak_ptr<_Tp> const& __x, weak_ptr<_Up> const& __y) const _NOEXCEPT {1384 return __x.owner_before(__y);1385 }1386 typedef void is_transparent;1387};1388#endif1389 1390template <class _Tp>1391class enable_shared_from_this {1392 mutable weak_ptr<_Tp> __weak_this_;1393 1394protected:1395 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR enable_shared_from_this() _NOEXCEPT {}1396 _LIBCPP_HIDE_FROM_ABI enable_shared_from_this(enable_shared_from_this const&) _NOEXCEPT {}1397 _LIBCPP_HIDE_FROM_ABI enable_shared_from_this& operator=(enable_shared_from_this const&) _NOEXCEPT { return *this; }1398 _LIBCPP_HIDE_FROM_ABI ~enable_shared_from_this() {}1399 1400public:1401 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> shared_from_this() { return shared_ptr<_Tp>(__weak_this_); }1402 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp const> shared_from_this() const {1403 return shared_ptr<const _Tp>(__weak_this_);1404 }1405 1406#if _LIBCPP_STD_VER >= 171407 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI weak_ptr<_Tp> weak_from_this() _NOEXCEPT { return __weak_this_; }1408 1409 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI weak_ptr<const _Tp> weak_from_this() const _NOEXCEPT { return __weak_this_; }1410#endif // _LIBCPP_STD_VER >= 171411 1412 template <class _Up>1413 friend class shared_ptr;1414};1415 1416template <class _Tp>1417struct hash;1418 1419template <class _Tp>1420struct hash<shared_ptr<_Tp> > {1421#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_BINDER_TYPEDEFS)1422 _LIBCPP_DEPRECATED_IN_CXX17 typedef shared_ptr<_Tp> argument_type;1423 _LIBCPP_DEPRECATED_IN_CXX17 typedef size_t result_type;1424#endif1425 1426 _LIBCPP_HIDE_FROM_ABI size_t operator()(const shared_ptr<_Tp>& __ptr) const _NOEXCEPT {1427 return hash<typename shared_ptr<_Tp>::element_type*>()(__ptr.get());1428 }1429};1430 1431template <class _CharT, class _Traits, class _Yp>1432inline _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>&1433operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p);1434 1435#if _LIBCPP_HAS_THREADS1436 1437class _LIBCPP_EXPORTED_FROM_ABI __sp_mut {1438 void* __lx_;1439 1440public:1441 void lock() _NOEXCEPT;1442 void unlock() _NOEXCEPT;1443 1444private:1445 _LIBCPP_CONSTEXPR __sp_mut(void*) _NOEXCEPT;1446 __sp_mut(const __sp_mut&);1447 __sp_mut& operator=(const __sp_mut&);1448 1449 friend _LIBCPP_EXPORTED_FROM_ABI __sp_mut& __get_sp_mut(const void*);1450};1451 1452_LIBCPP_EXPORTED_FROM_ABI __sp_mut& __get_sp_mut(const void*);1453 1454template <class _Tp>1455inline _LIBCPP_HIDE_FROM_ABI bool atomic_is_lock_free(const shared_ptr<_Tp>*) {1456 return false;1457}1458 1459template <class _Tp>1460_LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> atomic_load(const shared_ptr<_Tp>* __p) {1461 __sp_mut& __m = std::__get_sp_mut(__p);1462 __m.lock();1463 shared_ptr<_Tp> __q = *__p;1464 __m.unlock();1465 return __q;1466}1467 1468template <class _Tp>1469inline _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> atomic_load_explicit(const shared_ptr<_Tp>* __p, memory_order) {1470 return std::atomic_load(__p);1471}1472 1473template <class _Tp>1474_LIBCPP_HIDE_FROM_ABI void atomic_store(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r) {1475 __sp_mut& __m = std::__get_sp_mut(__p);1476 __m.lock();1477 __p->swap(__r);1478 __m.unlock();1479}1480 1481template <class _Tp>1482inline _LIBCPP_HIDE_FROM_ABI void atomic_store_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order) {1483 std::atomic_store(__p, __r);1484}1485 1486template <class _Tp>1487_LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> atomic_exchange(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r) {1488 __sp_mut& __m = std::__get_sp_mut(__p);1489 __m.lock();1490 __p->swap(__r);1491 __m.unlock();1492 return __r;1493}1494 1495template <class _Tp>1496inline _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>1497atomic_exchange_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order) {1498 return std::atomic_exchange(__p, __r);1499}1500 1501template <class _Tp>1502_LIBCPP_HIDE_FROM_ABI bool1503atomic_compare_exchange_strong(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w) {1504 shared_ptr<_Tp> __temp;1505 __sp_mut& __m = std::__get_sp_mut(__p);1506 __m.lock();1507 if (__p->__owner_equivalent(*__v)) {1508 std::swap(__temp, *__p);1509 *__p = __w;1510 __m.unlock();1511 return true;1512 }1513 std::swap(__temp, *__v);1514 *__v = *__p;1515 __m.unlock();1516 return false;1517}1518 1519template <class _Tp>1520inline _LIBCPP_HIDE_FROM_ABI bool1521atomic_compare_exchange_weak(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w) {1522 return std::atomic_compare_exchange_strong(__p, __v, __w);1523}1524 1525template <class _Tp>1526inline _LIBCPP_HIDE_FROM_ABI bool atomic_compare_exchange_strong_explicit(1527 shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w, memory_order, memory_order) {1528 return std::atomic_compare_exchange_strong(__p, __v, __w);1529}1530 1531template <class _Tp>1532inline _LIBCPP_HIDE_FROM_ABI bool atomic_compare_exchange_weak_explicit(1533 shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w, memory_order, memory_order) {1534 return std::atomic_compare_exchange_weak(__p, __v, __w);1535}1536 1537#endif // _LIBCPP_HAS_THREADS1538 1539_LIBCPP_END_NAMESPACE_STD1540 1541_LIBCPP_POP_MACROS1542 1543#endif // _LIBCPP___MEMORY_SHARED_PTR_H1544