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