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