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