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1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP___CXX03___MEMORY_SHARED_PTR_H
11#define _LIBCPP___CXX03___MEMORY_SHARED_PTR_H
12
13#include <__cxx03/__config>
14#include <__cxx03/__exception/exception.h>
15#include <__cxx03/__functional/binary_function.h>
16#include <__cxx03/__functional/operations.h>
17#include <__cxx03/__functional/reference_wrapper.h>
18#include <__cxx03/__fwd/ostream.h>
19#include <__cxx03/__iterator/access.h>
20#include <__cxx03/__memory/addressof.h>
21#include <__cxx03/__memory/allocation_guard.h>
22#include <__cxx03/__memory/allocator.h>
23#include <__cxx03/__memory/allocator_destructor.h>
24#include <__cxx03/__memory/allocator_traits.h>
25#include <__cxx03/__memory/auto_ptr.h>
26#include <__cxx03/__memory/compressed_pair.h>
27#include <__cxx03/__memory/construct_at.h>
28#include <__cxx03/__memory/pointer_traits.h>
29#include <__cxx03/__memory/uninitialized_algorithms.h>
30#include <__cxx03/__memory/unique_ptr.h>
31#include <__cxx03/__type_traits/add_lvalue_reference.h>
32#include <__cxx03/__type_traits/conditional.h>
33#include <__cxx03/__type_traits/conjunction.h>
34#include <__cxx03/__type_traits/disjunction.h>
35#include <__cxx03/__type_traits/is_array.h>
36#include <__cxx03/__type_traits/is_bounded_array.h>
37#include <__cxx03/__type_traits/is_constructible.h>
38#include <__cxx03/__type_traits/is_convertible.h>
39#include <__cxx03/__type_traits/is_reference.h>
40#include <__cxx03/__type_traits/is_unbounded_array.h>
41#include <__cxx03/__type_traits/nat.h>
42#include <__cxx03/__type_traits/negation.h>
43#include <__cxx03/__type_traits/remove_extent.h>
44#include <__cxx03/__type_traits/remove_reference.h>
45#include <__cxx03/__utility/declval.h>
46#include <__cxx03/__utility/forward.h>
47#include <__cxx03/__utility/move.h>
48#include <__cxx03/__utility/swap.h>
49#include <__cxx03/__verbose_abort>
50#include <__cxx03/cstddef>
51#include <__cxx03/new>
52#include <__cxx03/typeinfo>
53#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
54# include <__cxx03/__atomic/memory_order.h>
55#endif
56
57#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
58# pragma GCC system_header
59#endif
60
61_LIBCPP_PUSH_MACROS
62#include <__cxx03/__undef_macros>
63
64_LIBCPP_BEGIN_NAMESPACE_STD
65
66// NOTE: Relaxed and acq/rel atomics (for increment and decrement respectively)
67// should be sufficient for thread safety.
68// See https://llvm.org/PR22803
69#if defined(__clang__) && __has_builtin(__atomic_add_fetch) && defined(__ATOMIC_RELAXED) && defined(__ATOMIC_ACQ_REL)
70# define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
71#elif defined(_LIBCPP_COMPILER_GCC)
72# define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
73#endif
74
75template <class _ValueType>
76inline _LIBCPP_HIDE_FROM_ABI _ValueType __libcpp_relaxed_load(_ValueType const* __value) {
77#if !defined(_LIBCPP_HAS_NO_THREADS) && defined(__ATOMIC_RELAXED) && \
78 (__has_builtin(__atomic_load_n) || defined(_LIBCPP_COMPILER_GCC))
79 return __atomic_load_n(__value, __ATOMIC_RELAXED);
80#else
81 return *__value;
82#endif
83}
84
85template <class _ValueType>
86inline _LIBCPP_HIDE_FROM_ABI _ValueType __libcpp_acquire_load(_ValueType const* __value) {
87#if !defined(_LIBCPP_HAS_NO_THREADS) && defined(__ATOMIC_ACQUIRE) && \
88 (__has_builtin(__atomic_load_n) || defined(_LIBCPP_COMPILER_GCC))
89 return __atomic_load_n(__value, __ATOMIC_ACQUIRE);
90#else
91 return *__value;
92#endif
93}
94
95template <class _Tp>
96inline _LIBCPP_HIDE_FROM_ABI _Tp __libcpp_atomic_refcount_increment(_Tp& __t) _NOEXCEPT {
97#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
98 return __atomic_add_fetch(&__t, 1, __ATOMIC_RELAXED);
99#else
100 return __t += 1;
101#endif
102}
103
104template <class _Tp>
105inline _LIBCPP_HIDE_FROM_ABI _Tp __libcpp_atomic_refcount_decrement(_Tp& __t) _NOEXCEPT {
106#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
107 return __atomic_add_fetch(&__t, -1, __ATOMIC_ACQ_REL);
108#else
109 return __t -= 1;
110#endif
111}
112
113class _LIBCPP_EXPORTED_FROM_ABI bad_weak_ptr : public std::exception {
114public:
115 _LIBCPP_HIDE_FROM_ABI bad_weak_ptr() _NOEXCEPT = default;
116 _LIBCPP_HIDE_FROM_ABI bad_weak_ptr(const bad_weak_ptr&) _NOEXCEPT = default;
117 _LIBCPP_HIDE_FROM_ABI bad_weak_ptr& operator=(const bad_weak_ptr&) _NOEXCEPT = default;
118 ~bad_weak_ptr() _NOEXCEPT override;
119 const char* what() const _NOEXCEPT override;
120};
121
122_LIBCPP_NORETURN inline _LIBCPP_HIDE_FROM_ABI void __throw_bad_weak_ptr() {
123#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
124 throw bad_weak_ptr();
125#else
126 _LIBCPP_VERBOSE_ABORT("bad_weak_ptr was thrown in -fno-exceptions mode");
127#endif
128}
129
130template <class _Tp>
131class _LIBCPP_TEMPLATE_VIS weak_ptr;
132
133class _LIBCPP_EXPORTED_FROM_ABI __shared_count {
134 __shared_count(const __shared_count&);
135 __shared_count& operator=(const __shared_count&);
136
137protected:
138 long __shared_owners_;
139 virtual ~__shared_count();
140
141private:
142 virtual void __on_zero_shared() _NOEXCEPT = 0;
143
144public:
145 _LIBCPP_HIDE_FROM_ABI explicit __shared_count(long __refs = 0) _NOEXCEPT : __shared_owners_(__refs) {}
146
147#if defined(_LIBCPP_SHARED_PTR_DEFINE_LEGACY_INLINE_FUNCTIONS)
148 void __add_shared() noexcept;
149 bool __release_shared() noexcept;
150#else
151 _LIBCPP_HIDE_FROM_ABI void __add_shared() _NOEXCEPT { __libcpp_atomic_refcount_increment(__shared_owners_); }
152 _LIBCPP_HIDE_FROM_ABI bool __release_shared() _NOEXCEPT {
153 if (__libcpp_atomic_refcount_decrement(__shared_owners_) == -1) {
154 __on_zero_shared();
155 return true;
156 }
157 return false;
158 }
159#endif
160 _LIBCPP_HIDE_FROM_ABI long use_count() const _NOEXCEPT { return __libcpp_relaxed_load(&__shared_owners_) + 1; }
161};
162
163class _LIBCPP_EXPORTED_FROM_ABI __shared_weak_count : private __shared_count {
164 long __shared_weak_owners_;
165
166public:
167 _LIBCPP_HIDE_FROM_ABI explicit __shared_weak_count(long __refs = 0) _NOEXCEPT
168 : __shared_count(__refs),
169 __shared_weak_owners_(__refs) {}
170
171protected:
172 ~__shared_weak_count() override;
173
174public:
175#if defined(_LIBCPP_SHARED_PTR_DEFINE_LEGACY_INLINE_FUNCTIONS)
176 void __add_shared() noexcept;
177 void __add_weak() noexcept;
178 void __release_shared() noexcept;
179#else
180 _LIBCPP_HIDE_FROM_ABI void __add_shared() _NOEXCEPT { __shared_count::__add_shared(); }
181 _LIBCPP_HIDE_FROM_ABI void __add_weak() _NOEXCEPT { __libcpp_atomic_refcount_increment(__shared_weak_owners_); }
182 _LIBCPP_HIDE_FROM_ABI void __release_shared() _NOEXCEPT {
183 if (__shared_count::__release_shared())
184 __release_weak();
185 }
186#endif
187 void __release_weak() _NOEXCEPT;
188 _LIBCPP_HIDE_FROM_ABI long use_count() const _NOEXCEPT { return __shared_count::use_count(); }
189 __shared_weak_count* lock() _NOEXCEPT;
190
191 virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
192
193private:
194 virtual void __on_zero_shared_weak() _NOEXCEPT = 0;
195};
196
197template <class _Tp, class _Dp, class _Alloc>
198class __shared_ptr_pointer : public __shared_weak_count {
199 __compressed_pair<__compressed_pair<_Tp, _Dp>, _Alloc> __data_;
200
201public:
202 _LIBCPP_HIDE_FROM_ABI __shared_ptr_pointer(_Tp __p, _Dp __d, _Alloc __a)
203 : __data_(__compressed_pair<_Tp, _Dp>(__p, std::move(__d)), std::move(__a)) {}
204
205#ifndef _LIBCPP_HAS_NO_RTTI
206 _LIBCPP_HIDE_FROM_ABI_VIRTUAL const void* __get_deleter(const type_info&) const _NOEXCEPT override;
207#endif
208
209private:
210 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override;
211 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared_weak() _NOEXCEPT override;
212};
213
214#ifndef _LIBCPP_HAS_NO_RTTI
215
216template <class _Tp, class _Dp, class _Alloc>
217const void* __shared_ptr_pointer<_Tp, _Dp, _Alloc>::__get_deleter(const type_info& __t) const _NOEXCEPT {
218 return __t == typeid(_Dp) ? std::addressof(__data_.first().second()) : nullptr;
219}
220
221#endif // _LIBCPP_HAS_NO_RTTI
222
223template <class _Tp, class _Dp, class _Alloc>
224void __shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared() _NOEXCEPT {
225 __data_.first().second()(__data_.first().first());
226 __data_.first().second().~_Dp();
227}
228
229template <class _Tp, class _Dp, class _Alloc>
230void __shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT {
231 typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_pointer>::type _Al;
232 typedef allocator_traits<_Al> _ATraits;
233 typedef pointer_traits<typename _ATraits::pointer> _PTraits;
234
235 _Al __a(__data_.second());
236 __data_.second().~_Alloc();
237 __a.deallocate(_PTraits::pointer_to(*this), 1);
238}
239
240// This tag is used to instantiate an allocator type. The various shared_ptr control blocks
241// detect that the allocator has been instantiated for this type and perform alternative
242// initialization/destruction based on that.
243struct __for_overwrite_tag {};
244
245template <class _Tp, class _Alloc>
246struct __shared_ptr_emplace : __shared_weak_count {
247 template <class... _Args,
248 class _Allocator = _Alloc,
249 __enable_if_t<is_same<typename _Allocator::value_type, __for_overwrite_tag>::value, int> = 0>
250 _LIBCPP_HIDE_FROM_ABI explicit __shared_ptr_emplace(_Alloc __a, _Args&&...) : __storage_(std::move(__a)) {
251 static_assert(
252 sizeof...(_Args) == 0, "No argument should be provided to the control block when using _for_overwrite");
253 ::new ((void*)__get_elem()) _Tp;
254 }
255
256 template <class... _Args,
257 class _Allocator = _Alloc,
258 __enable_if_t<!is_same<typename _Allocator::value_type, __for_overwrite_tag>::value, int> = 0>
259 _LIBCPP_HIDE_FROM_ABI explicit __shared_ptr_emplace(_Alloc __a, _Args&&... __args) : __storage_(std::move(__a)) {
260 using _TpAlloc = typename __allocator_traits_rebind<_Alloc, __remove_cv_t<_Tp> >::type;
261 _TpAlloc __tmp(*__get_alloc());
262 allocator_traits<_TpAlloc>::construct(__tmp, __get_elem(), std::forward<_Args>(__args)...);
263 }
264
265 _LIBCPP_HIDE_FROM_ABI _Alloc* __get_alloc() _NOEXCEPT { return __storage_.__get_alloc(); }
266
267 _LIBCPP_HIDE_FROM_ABI _Tp* __get_elem() _NOEXCEPT { return __storage_.__get_elem(); }
268
269private:
270 template <class _Allocator = _Alloc,
271 __enable_if_t<is_same<typename _Allocator::value_type, __for_overwrite_tag>::value, int> = 0>
272 _LIBCPP_HIDE_FROM_ABI void __on_zero_shared_impl() _NOEXCEPT {
273 __get_elem()->~_Tp();
274 }
275
276 template <class _Allocator = _Alloc,
277 __enable_if_t<!is_same<typename _Allocator::value_type, __for_overwrite_tag>::value, int> = 0>
278 _LIBCPP_HIDE_FROM_ABI void __on_zero_shared_impl() _NOEXCEPT {
279 using _TpAlloc = typename __allocator_traits_rebind<_Allocator, __remove_cv_t<_Tp> >::type;
280 _TpAlloc __tmp(*__get_alloc());
281 allocator_traits<_TpAlloc>::destroy(__tmp, __get_elem());
282 }
283
284 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override { __on_zero_shared_impl(); }
285
286 _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared_weak() _NOEXCEPT override {
287 using _ControlBlockAlloc = typename __allocator_traits_rebind<_Alloc, __shared_ptr_emplace>::type;
288 using _ControlBlockPointer = typename allocator_traits<_ControlBlockAlloc>::pointer;
289 _ControlBlockAlloc __tmp(*__get_alloc());
290 __storage_.~_Storage();
291 allocator_traits<_ControlBlockAlloc>::deallocate(__tmp, pointer_traits<_ControlBlockPointer>::pointer_to(*this), 1);
292 }
293
294 // This class implements the control block for non-array shared pointers created
295 // through `std::allocate_shared` and `std::make_shared`.
296 //
297 // In previous versions of the library, we used a compressed pair to store
298 // both the _Alloc and the _Tp. This implies using EBO, which is incompatible
299 // with Allocator construction for _Tp. To allow implementing P0674 in C++20,
300 // we now use a properly aligned char buffer while making sure that we maintain
301 // the same layout that we had when we used a compressed pair.
302 using _CompressedPair = __compressed_pair<_Alloc, _Tp>;
303 struct _ALIGNAS_TYPE(_CompressedPair) _Storage {
304 char __blob_[sizeof(_CompressedPair)];
305
306 _LIBCPP_HIDE_FROM_ABI explicit _Storage(_Alloc&& __a) { ::new ((void*)__get_alloc()) _Alloc(std::move(__a)); }
307 _LIBCPP_HIDE_FROM_ABI ~_Storage() { __get_alloc()->~_Alloc(); }
308 _LIBCPP_HIDE_FROM_ABI _Alloc* __get_alloc() _NOEXCEPT {
309 _CompressedPair* __as_pair = reinterpret_cast<_CompressedPair*>(__blob_);
310 typename _CompressedPair::_Base1* __first = _CompressedPair::__get_first_base(__as_pair);
311 _Alloc* __alloc = reinterpret_cast<_Alloc*>(__first);
312 return __alloc;
313 }
314 _LIBCPP_HIDE_FROM_ABI _LIBCPP_NO_CFI _Tp* __get_elem() _NOEXCEPT {
315 _CompressedPair* __as_pair = reinterpret_cast<_CompressedPair*>(__blob_);
316 typename _CompressedPair::_Base2* __second = _CompressedPair::__get_second_base(__as_pair);
317 _Tp* __elem = reinterpret_cast<_Tp*>(__second);
318 return __elem;
319 }
320 };
321
322 static_assert(_LIBCPP_ALIGNOF(_Storage) == _LIBCPP_ALIGNOF(_CompressedPair), "");
323 static_assert(sizeof(_Storage) == sizeof(_CompressedPair), "");
324 _Storage __storage_;
325};
326
327struct __shared_ptr_dummy_rebind_allocator_type;
328template <>
329class _LIBCPP_TEMPLATE_VIS allocator<__shared_ptr_dummy_rebind_allocator_type> {
330public:
331 template <class _Other>
332 struct rebind {
333 typedef allocator<_Other> other;
334 };
335};
336
337template <class _Tp>
338class _LIBCPP_TEMPLATE_VIS enable_shared_from_this;
339
340// http://eel.is/c++draft/util.sharedptr#util.smartptr.shared.general-6
341// A pointer type Y* is said to be compatible with a pointer type T*
342// when either Y* is convertible to T* or Y is U[N] and T is cv U[].
343template <class _Yp, class _Tp>
344struct __compatible_with : is_convertible<_Yp*, _Tp*> {};
345
346// Constructors that take raw pointers have a different set of "compatible" constraints
347// http://eel.is/c++draft/util.sharedptr#util.smartptr.shared.const-9.1
348// - If T is an array type, then either T is U[N] and Y(*)[N] is convertible to T*,
349// or T is U[] and Y(*)[] is convertible to T*.
350// - If T is not an array type, then Y* is convertible to T*.
351template <class _Yp, class _Tp>
352struct __raw_pointer_compatible_with : is_convertible<_Yp*, _Tp*> {};
353
354template <class _Ptr, class = void>
355struct __is_deletable : false_type {};
356template <class _Ptr>
357struct __is_deletable<_Ptr, decltype(delete std::declval<_Ptr>())> : true_type {};
358
359template <class _Ptr, class = void>
360struct __is_array_deletable : false_type {};
361template <class _Ptr>
362struct __is_array_deletable<_Ptr, decltype(delete[] std::declval<_Ptr>())> : true_type {};
363
364template <class _Dp, class _Pt, class = decltype(std::declval<_Dp>()(std::declval<_Pt>()))>
365true_type __well_formed_deleter_test(int);
366
367template <class, class>
368false_type __well_formed_deleter_test(...);
369
370template <class _Dp, class _Pt>
371struct __well_formed_deleter : decltype(std::__well_formed_deleter_test<_Dp, _Pt>(0)) {};
372
373template <class _Dp, class _Yp, class _Tp>
374struct __shared_ptr_deleter_ctor_reqs {
375 static const bool value = __raw_pointer_compatible_with<_Yp, _Tp>::value && is_move_constructible<_Dp>::value &&
376 __well_formed_deleter<_Dp, _Yp*>::value;
377};
378
379template <class _Dp>
380using __shared_ptr_nullptr_deleter_ctor_reqs = _And<is_move_constructible<_Dp>, __well_formed_deleter<_Dp, nullptr_t> >;
381
382#if defined(_LIBCPP_ABI_ENABLE_SHARED_PTR_TRIVIAL_ABI)
383# define _LIBCPP_SHARED_PTR_TRIVIAL_ABI __attribute__((__trivial_abi__))
384#else
385# define _LIBCPP_SHARED_PTR_TRIVIAL_ABI
386#endif
387
388template <class _Tp>
389class _LIBCPP_SHARED_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS shared_ptr {
390 struct __nullptr_sfinae_tag {};
391
392public:
393 typedef _Tp element_type;
394
395 // A shared_ptr contains only two raw pointers which point to the heap and move constructing already doesn't require
396 // any bookkeeping, so it's always trivially relocatable.
397 using __trivially_relocatable = shared_ptr;
398
399private:
400 element_type* __ptr_;
401 __shared_weak_count* __cntrl_;
402
403public:
404 _LIBCPP_HIDE_FROM_ABI shared_ptr() _NOEXCEPT : __ptr_(nullptr), __cntrl_(nullptr) {}
405
406 _LIBCPP_HIDE_FROM_ABI shared_ptr(nullptr_t) _NOEXCEPT : __ptr_(nullptr), __cntrl_(nullptr) {}
407
408 template <class _Yp, __enable_if_t< _And< __raw_pointer_compatible_with<_Yp, _Tp> >::value, int> = 0>
409 _LIBCPP_HIDE_FROM_ABI explicit shared_ptr(_Yp* __p) : __ptr_(__p) {
410 unique_ptr<_Yp> __hold(__p);
411 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
412 typedef __shared_ptr_pointer<_Yp*, __shared_ptr_default_delete<_Tp, _Yp>, _AllocT> _CntrlBlk;
413 __cntrl_ = new _CntrlBlk(__p, __shared_ptr_default_delete<_Tp, _Yp>(), _AllocT());
414 __hold.release();
415 __enable_weak_this(__p, __p);
416 }
417
418 template <class _Yp, class _Dp, __enable_if_t<__shared_ptr_deleter_ctor_reqs<_Dp, _Yp, _Tp>::value, int> = 0>
419 _LIBCPP_HIDE_FROM_ABI shared_ptr(_Yp* __p, _Dp __d) : __ptr_(__p) {
420#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
421 try {
422#endif // _LIBCPP_HAS_NO_EXCEPTIONS
423 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
424 typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT> _CntrlBlk;
425 __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
426 __enable_weak_this(__p, __p);
427#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
428 } catch (...) {
429 __d(__p);
430 throw;
431 }
432#endif // _LIBCPP_HAS_NO_EXCEPTIONS
433 }
434
435 template <class _Yp,
436 class _Dp,
437 class _Alloc,
438 __enable_if_t<__shared_ptr_deleter_ctor_reqs<_Dp, _Yp, _Tp>::value, int> = 0>
439 _LIBCPP_HIDE_FROM_ABI shared_ptr(_Yp* __p, _Dp __d, _Alloc __a) : __ptr_(__p) {
440#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
441 try {
442#endif // _LIBCPP_HAS_NO_EXCEPTIONS
443 typedef __shared_ptr_pointer<_Yp*, _Dp, _Alloc> _CntrlBlk;
444 typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
445 typedef __allocator_destructor<_A2> _D2;
446 _A2 __a2(__a);
447 unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
448 ::new ((void*)std::addressof(*__hold2.get())) _CntrlBlk(__p, __d, __a);
449 __cntrl_ = std::addressof(*__hold2.release());
450 __enable_weak_this(__p, __p);
451#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
452 } catch (...) {
453 __d(__p);
454 throw;
455 }
456#endif // _LIBCPP_HAS_NO_EXCEPTIONS
457 }
458
459 template <class _Dp>
460 _LIBCPP_HIDE_FROM_ABI shared_ptr(
461 nullptr_t __p,
462 _Dp __d,
463 __enable_if_t<__shared_ptr_nullptr_deleter_ctor_reqs<_Dp>::value, __nullptr_sfinae_tag> = __nullptr_sfinae_tag())
464 : __ptr_(nullptr) {
465#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
466 try {
467#endif // _LIBCPP_HAS_NO_EXCEPTIONS
468 typedef typename __shared_ptr_default_allocator<_Tp>::type _AllocT;
469 typedef __shared_ptr_pointer<nullptr_t, _Dp, _AllocT> _CntrlBlk;
470 __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
471#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
472 } catch (...) {
473 __d(__p);
474 throw;
475 }
476#endif // _LIBCPP_HAS_NO_EXCEPTIONS
477 }
478
479 template <class _Dp, class _Alloc>
480 _LIBCPP_HIDE_FROM_ABI shared_ptr(
481 nullptr_t __p,
482 _Dp __d,
483 _Alloc __a,
484 __enable_if_t<__shared_ptr_nullptr_deleter_ctor_reqs<_Dp>::value, __nullptr_sfinae_tag> = __nullptr_sfinae_tag())
485 : __ptr_(nullptr) {
486#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
487 try {
488#endif // _LIBCPP_HAS_NO_EXCEPTIONS
489 typedef __shared_ptr_pointer<nullptr_t, _Dp, _Alloc> _CntrlBlk;
490 typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
491 typedef __allocator_destructor<_A2> _D2;
492 _A2 __a2(__a);
493 unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
494 ::new ((void*)std::addressof(*__hold2.get())) _CntrlBlk(__p, __d, __a);
495 __cntrl_ = std::addressof(*__hold2.release());
496#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
497 } catch (...) {
498 __d(__p);
499 throw;
500 }
501#endif // _LIBCPP_HAS_NO_EXCEPTIONS
502 }
503
504 template <class _Yp>
505 _LIBCPP_HIDE_FROM_ABI shared_ptr(const shared_ptr<_Yp>& __r, element_type* __p) _NOEXCEPT
506 : __ptr_(__p),
507 __cntrl_(__r.__cntrl_) {
508 if (__cntrl_)
509 __cntrl_->__add_shared();
510 }
511
512 _LIBCPP_HIDE_FROM_ABI shared_ptr(const shared_ptr& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) {
513 if (__cntrl_)
514 __cntrl_->__add_shared();
515 }
516
517 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>
518 _LIBCPP_HIDE_FROM_ABI shared_ptr(const shared_ptr<_Yp>& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) {
519 if (__cntrl_)
520 __cntrl_->__add_shared();
521 }
522
523 _LIBCPP_HIDE_FROM_ABI shared_ptr(shared_ptr&& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) {
524 __r.__ptr_ = nullptr;
525 __r.__cntrl_ = nullptr;
526 }
527
528 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>
529 _LIBCPP_HIDE_FROM_ABI shared_ptr(shared_ptr<_Yp>&& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) {
530 __r.__ptr_ = nullptr;
531 __r.__cntrl_ = nullptr;
532 }
533
534 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>
535 _LIBCPP_HIDE_FROM_ABI explicit shared_ptr(const weak_ptr<_Yp>& __r)
536 : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_ ? __r.__cntrl_->lock() : __r.__cntrl_) {
537 if (__cntrl_ == nullptr)
538 __throw_bad_weak_ptr();
539 }
540
541 template <class _Yp, __enable_if_t<is_convertible<_Yp*, element_type*>::value, int> = 0>
542 _LIBCPP_HIDE_FROM_ABI shared_ptr(auto_ptr<_Yp>&& __r) : __ptr_(__r.get()) {
543 typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<__remove_cv_t<_Yp> > > _CntrlBlk;
544 __cntrl_ = new _CntrlBlk(__r.get(), default_delete<_Yp>(), allocator<__remove_cv_t<_Yp> >());
545 __enable_weak_this(__r.get(), __r.get());
546 __r.release();
547 }
548
549 template <class _Yp,
550 class _Dp,
551 __enable_if_t<!is_lvalue_reference<_Dp>::value && __compatible_with<_Yp, _Tp>::value &&
552 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
553 int> = 0>
554 _LIBCPP_HIDE_FROM_ABI shared_ptr(unique_ptr<_Yp, _Dp>&& __r) : __ptr_(__r.get()) {
555 {
556 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
557 typedef __shared_ptr_pointer<typename unique_ptr<_Yp, _Dp>::pointer, _Dp, _AllocT> _CntrlBlk;
558 __cntrl_ = new _CntrlBlk(__r.get(), std::move(__r.get_deleter()), _AllocT());
559 __enable_weak_this(__r.get(), __r.get());
560 }
561 __r.release();
562 }
563
564 template <class _Yp,
565 class _Dp,
566 class = void,
567 __enable_if_t<is_lvalue_reference<_Dp>::value && __compatible_with<_Yp, _Tp>::value &&
568 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
569 int> = 0>
570 _LIBCPP_HIDE_FROM_ABI shared_ptr(unique_ptr<_Yp, _Dp>&& __r) : __ptr_(__r.get()) {
571 {
572 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
573 typedef __shared_ptr_pointer<typename unique_ptr<_Yp, _Dp>::pointer,
574 reference_wrapper<__libcpp_remove_reference_t<_Dp> >,
575 _AllocT>
576 _CntrlBlk;
577 __cntrl_ = new _CntrlBlk(__r.get(), std::ref(__r.get_deleter()), _AllocT());
578 __enable_weak_this(__r.get(), __r.get());
579 }
580 __r.release();
581 }
582
583 _LIBCPP_HIDE_FROM_ABI ~shared_ptr() {
584 if (__cntrl_)
585 __cntrl_->__release_shared();
586 }
587
588 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(const shared_ptr& __r) _NOEXCEPT {
589 shared_ptr(__r).swap(*this);
590 return *this;
591 }
592
593 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>
594 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT {
595 shared_ptr(__r).swap(*this);
596 return *this;
597 }
598
599 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(shared_ptr&& __r) _NOEXCEPT {
600 shared_ptr(std::move(__r)).swap(*this);
601 return *this;
602 }
603
604 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>
605 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(shared_ptr<_Yp>&& __r) {
606 shared_ptr(std::move(__r)).swap(*this);
607 return *this;
608 }
609
610 template <class _Yp,
611 __enable_if_t<!is_array<_Yp>::value && is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
612 int> = 0>
613 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(auto_ptr<_Yp>&& __r) {
614 shared_ptr(std::move(__r)).swap(*this);
615 return *this;
616 }
617
618 template <class _Yp,
619 class _Dp,
620 __enable_if_t<_And< __compatible_with<_Yp, _Tp>,
621 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*> >::value,
622 int> = 0>
623 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>& operator=(unique_ptr<_Yp, _Dp>&& __r) {
624 shared_ptr(std::move(__r)).swap(*this);
625 return *this;
626 }
627
628 _LIBCPP_HIDE_FROM_ABI void swap(shared_ptr& __r) _NOEXCEPT {
629 std::swap(__ptr_, __r.__ptr_);
630 std::swap(__cntrl_, __r.__cntrl_);
631 }
632
633 _LIBCPP_HIDE_FROM_ABI void reset() _NOEXCEPT { shared_ptr().swap(*this); }
634
635 template <class _Yp, __enable_if_t<__raw_pointer_compatible_with<_Yp, _Tp>::value, int> = 0>
636 _LIBCPP_HIDE_FROM_ABI void reset(_Yp* __p) {
637 shared_ptr(__p).swap(*this);
638 }
639
640 template <class _Yp, class _Dp, __enable_if_t<__shared_ptr_deleter_ctor_reqs<_Dp, _Yp, _Tp>::value, int> = 0>
641 _LIBCPP_HIDE_FROM_ABI void reset(_Yp* __p, _Dp __d) {
642 shared_ptr(__p, __d).swap(*this);
643 }
644
645 template <class _Yp,
646 class _Dp,
647 class _Alloc,
648 __enable_if_t<__shared_ptr_deleter_ctor_reqs<_Dp, _Yp, _Tp>::value, int> = 0>
649 _LIBCPP_HIDE_FROM_ABI void reset(_Yp* __p, _Dp __d, _Alloc __a) {
650 shared_ptr(__p, __d, __a).swap(*this);
651 }
652
653 _LIBCPP_HIDE_FROM_ABI element_type* get() const _NOEXCEPT { return __ptr_; }
654
655 _LIBCPP_HIDE_FROM_ABI __add_lvalue_reference_t<element_type> operator*() const _NOEXCEPT { return *__ptr_; }
656
657 _LIBCPP_HIDE_FROM_ABI element_type* operator->() const _NOEXCEPT {
658 static_assert(!is_array<_Tp>::value, "std::shared_ptr<T>::operator-> is only valid when T is not an array type.");
659 return __ptr_;
660 }
661
662 _LIBCPP_HIDE_FROM_ABI long use_count() const _NOEXCEPT { return __cntrl_ ? __cntrl_->use_count() : 0; }
663
664 _LIBCPP_HIDE_FROM_ABI bool unique() const _NOEXCEPT { return use_count() == 1; }
665
666 _LIBCPP_HIDE_FROM_ABI explicit operator bool() const _NOEXCEPT { return get() != nullptr; }
667
668 template <class _Up>
669 _LIBCPP_HIDE_FROM_ABI bool owner_before(shared_ptr<_Up> const& __p) const _NOEXCEPT {
670 return __cntrl_ < __p.__cntrl_;
671 }
672
673 template <class _Up>
674 _LIBCPP_HIDE_FROM_ABI bool owner_before(weak_ptr<_Up> const& __p) const _NOEXCEPT {
675 return __cntrl_ < __p.__cntrl_;
676 }
677
678 _LIBCPP_HIDE_FROM_ABI bool __owner_equivalent(const shared_ptr& __p) const { return __cntrl_ == __p.__cntrl_; }
679
680#ifndef _LIBCPP_HAS_NO_RTTI
681 template <class _Dp>
682 _LIBCPP_HIDE_FROM_ABI _Dp* __get_deleter() const _NOEXCEPT {
683 return static_cast<_Dp*>(__cntrl_ ? const_cast<void*>(__cntrl_->__get_deleter(typeid(_Dp))) : nullptr);
684 }
685#endif // _LIBCPP_HAS_NO_RTTI
686
687 template <class _Yp, class _CntrlBlk>
688 _LIBCPP_HIDE_FROM_ABI static shared_ptr<_Tp> __create_with_control_block(_Yp* __p, _CntrlBlk* __cntrl) _NOEXCEPT {
689 shared_ptr<_Tp> __r;
690 __r.__ptr_ = __p;
691 __r.__cntrl_ = __cntrl;
692 __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
693 return __r;
694 }
695
696private:
697 template <class _Yp, bool = is_function<_Yp>::value>
698 struct __shared_ptr_default_allocator {
699 typedef allocator<__remove_cv_t<_Yp> > type;
700 };
701
702 template <class _Yp>
703 struct __shared_ptr_default_allocator<_Yp, true> {
704 typedef allocator<__shared_ptr_dummy_rebind_allocator_type> type;
705 };
706
707 template <class _Yp,
708 class _OrigPtr,
709 __enable_if_t<is_convertible<_OrigPtr*, const enable_shared_from_this<_Yp>*>::value, int> = 0>
710 _LIBCPP_HIDE_FROM_ABI void __enable_weak_this(const enable_shared_from_this<_Yp>* __e, _OrigPtr* __ptr) _NOEXCEPT {
711 typedef __remove_cv_t<_Yp> _RawYp;
712 if (__e && __e->__weak_this_.expired()) {
713 __e->__weak_this_ = shared_ptr<_RawYp>(*this, const_cast<_RawYp*>(static_cast<const _Yp*>(__ptr)));
714 }
715 }
716
717 _LIBCPP_HIDE_FROM_ABI void __enable_weak_this(...) _NOEXCEPT {}
718
719 template <class, class _Yp>
720 struct __shared_ptr_default_delete : default_delete<_Yp> {};
721
722 template <class _Yp, class _Un, size_t _Sz>
723 struct __shared_ptr_default_delete<_Yp[_Sz], _Un> : default_delete<_Yp[]> {};
724
725 template <class _Yp, class _Un>
726 struct __shared_ptr_default_delete<_Yp[], _Un> : default_delete<_Yp[]> {};
727
728 template <class _Up>
729 friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
730 template <class _Up>
731 friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
732};
733
734//
735// std::allocate_shared and std::make_shared
736//
737template <class _Tp, class _Alloc, class... _Args, __enable_if_t<!is_array<_Tp>::value, int> = 0>
738_LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> allocate_shared(const _Alloc& __a, _Args&&... __args) {
739 using _ControlBlock = __shared_ptr_emplace<_Tp, _Alloc>;
740 using _ControlBlockAllocator = typename __allocator_traits_rebind<_Alloc, _ControlBlock>::type;
741 __allocation_guard<_ControlBlockAllocator> __guard(__a, 1);
742 ::new ((void*)std::addressof(*__guard.__get())) _ControlBlock(__a, std::forward<_Args>(__args)...);
743 auto __control_block = __guard.__release_ptr();
744 return shared_ptr<_Tp>::__create_with_control_block(
745 (*__control_block).__get_elem(), std::addressof(*__control_block));
746}
747
748template <class _Tp, class... _Args, __enable_if_t<!is_array<_Tp>::value, int> = 0>
749_LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> make_shared(_Args&&... __args) {
750 return std::allocate_shared<_Tp>(allocator<__remove_cv_t<_Tp> >(), std::forward<_Args>(__args)...);
751}
752
753template <class _Tp, class _Up>
754inline _LIBCPP_HIDE_FROM_ABI bool operator==(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT {
755 return __x.get() == __y.get();
756}
757
758template <class _Tp, class _Up>
759inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT {
760 return !(__x == __y);
761}
762
763template <class _Tp, class _Up>
764inline _LIBCPP_HIDE_FROM_ABI bool operator<(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT {
765 typedef typename common_type<_Tp*, _Up*>::type _Vp;
766 return less<_Vp>()(__x.get(), __y.get());
767}
768
769template <class _Tp, class _Up>
770inline _LIBCPP_HIDE_FROM_ABI bool operator>(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT {
771 return __y < __x;
772}
773
774template <class _Tp, class _Up>
775inline _LIBCPP_HIDE_FROM_ABI bool operator<=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT {
776 return !(__y < __x);
777}
778
779template <class _Tp, class _Up>
780inline _LIBCPP_HIDE_FROM_ABI bool operator>=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT {
781 return !(__x < __y);
782}
783
784template <class _Tp>
785inline _LIBCPP_HIDE_FROM_ABI bool operator==(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT {
786 return !__x;
787}
788
789template <class _Tp>
790inline _LIBCPP_HIDE_FROM_ABI bool operator==(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT {
791 return !__x;
792}
793
794template <class _Tp>
795inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT {
796 return static_cast<bool>(__x);
797}
798
799template <class _Tp>
800inline _LIBCPP_HIDE_FROM_ABI bool operator!=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT {
801 return static_cast<bool>(__x);
802}
803
804template <class _Tp>
805inline _LIBCPP_HIDE_FROM_ABI bool operator<(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT {
806 return less<typename shared_ptr<_Tp>::element_type*>()(__x.get(), nullptr);
807}
808
809template <class _Tp>
810inline _LIBCPP_HIDE_FROM_ABI bool operator<(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT {
811 return less<typename shared_ptr<_Tp>::element_type*>()(nullptr, __x.get());
812}
813
814template <class _Tp>
815inline _LIBCPP_HIDE_FROM_ABI bool operator>(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT {
816 return nullptr < __x;
817}
818
819template <class _Tp>
820inline _LIBCPP_HIDE_FROM_ABI bool operator>(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT {
821 return __x < nullptr;
822}
823
824template <class _Tp>
825inline _LIBCPP_HIDE_FROM_ABI bool operator<=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT {
826 return !(nullptr < __x);
827}
828
829template <class _Tp>
830inline _LIBCPP_HIDE_FROM_ABI bool operator<=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT {
831 return !(__x < nullptr);
832}
833
834template <class _Tp>
835inline _LIBCPP_HIDE_FROM_ABI bool operator>=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT {
836 return !(__x < nullptr);
837}
838
839template <class _Tp>
840inline _LIBCPP_HIDE_FROM_ABI bool operator>=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT {
841 return !(nullptr < __x);
842}
843
844template <class _Tp>
845inline _LIBCPP_HIDE_FROM_ABI void swap(shared_ptr<_Tp>& __x, shared_ptr<_Tp>& __y) _NOEXCEPT {
846 __x.swap(__y);
847}
848
849template <class _Tp, class _Up>
850inline _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> static_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT {
851 return shared_ptr<_Tp>(__r, static_cast< typename shared_ptr<_Tp>::element_type*>(__r.get()));
852}
853
854template <class _Tp, class _Up>
855inline _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> dynamic_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT {
856 typedef typename shared_ptr<_Tp>::element_type _ET;
857 _ET* __p = dynamic_cast<_ET*>(__r.get());
858 return __p ? shared_ptr<_Tp>(__r, __p) : shared_ptr<_Tp>();
859}
860
861template <class _Tp, class _Up>
862_LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> const_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT {
863 typedef typename shared_ptr<_Tp>::element_type _RTp;
864 return shared_ptr<_Tp>(__r, const_cast<_RTp*>(__r.get()));
865}
866
867template <class _Tp, class _Up>
868_LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> reinterpret_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT {
869 return shared_ptr<_Tp>(__r, reinterpret_cast< typename shared_ptr<_Tp>::element_type*>(__r.get()));
870}
871
872#ifndef _LIBCPP_HAS_NO_RTTI
873
874template <class _Dp, class _Tp>
875inline _LIBCPP_HIDE_FROM_ABI _Dp* get_deleter(const shared_ptr<_Tp>& __p) _NOEXCEPT {
876 return __p.template __get_deleter<_Dp>();
877}
878
879#endif // _LIBCPP_HAS_NO_RTTI
880
881template <class _Tp>
882class _LIBCPP_SHARED_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS weak_ptr {
883public:
884 typedef _Tp element_type;
885
886 // A weak_ptr contains only two raw pointers which point to the heap and move constructing already doesn't require
887 // any bookkeeping, so it's always trivially relocatable.
888 using __trivially_relocatable = weak_ptr;
889
890private:
891 element_type* __ptr_;
892 __shared_weak_count* __cntrl_;
893
894public:
895 _LIBCPP_HIDE_FROM_ABI weak_ptr() _NOEXCEPT;
896
897 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>
898 _LIBCPP_HIDE_FROM_ABI weak_ptr(shared_ptr<_Yp> const& __r) _NOEXCEPT;
899
900 _LIBCPP_HIDE_FROM_ABI weak_ptr(weak_ptr const& __r) _NOEXCEPT;
901
902 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>
903 _LIBCPP_HIDE_FROM_ABI weak_ptr(weak_ptr<_Yp> const& __r) _NOEXCEPT;
904
905 _LIBCPP_HIDE_FROM_ABI weak_ptr(weak_ptr&& __r) _NOEXCEPT;
906
907 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>
908 _LIBCPP_HIDE_FROM_ABI weak_ptr(weak_ptr<_Yp>&& __r) _NOEXCEPT;
909
910 _LIBCPP_HIDE_FROM_ABI ~weak_ptr();
911
912 _LIBCPP_HIDE_FROM_ABI weak_ptr& operator=(weak_ptr const& __r) _NOEXCEPT;
913 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>
914 _LIBCPP_HIDE_FROM_ABI weak_ptr& operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT;
915
916 _LIBCPP_HIDE_FROM_ABI weak_ptr& operator=(weak_ptr&& __r) _NOEXCEPT;
917 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>
918 _LIBCPP_HIDE_FROM_ABI weak_ptr& operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT;
919
920 template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> = 0>
921 _LIBCPP_HIDE_FROM_ABI weak_ptr& operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT;
922
923 _LIBCPP_HIDE_FROM_ABI void swap(weak_ptr& __r) _NOEXCEPT;
924 _LIBCPP_HIDE_FROM_ABI void reset() _NOEXCEPT;
925
926 _LIBCPP_HIDE_FROM_ABI long use_count() const _NOEXCEPT { return __cntrl_ ? __cntrl_->use_count() : 0; }
927 _LIBCPP_HIDE_FROM_ABI bool expired() const _NOEXCEPT { return __cntrl_ == nullptr || __cntrl_->use_count() == 0; }
928 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> lock() const _NOEXCEPT;
929 template <class _Up>
930 _LIBCPP_HIDE_FROM_ABI bool owner_before(const shared_ptr<_Up>& __r) const _NOEXCEPT {
931 return __cntrl_ < __r.__cntrl_;
932 }
933 template <class _Up>
934 _LIBCPP_HIDE_FROM_ABI bool owner_before(const weak_ptr<_Up>& __r) const _NOEXCEPT {
935 return __cntrl_ < __r.__cntrl_;
936 }
937
938 template <class _Up>
939 friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
940 template <class _Up>
941 friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
942};
943
944template <class _Tp>
945inline weak_ptr<_Tp>::weak_ptr() _NOEXCEPT : __ptr_(nullptr), __cntrl_(nullptr) {}
946
947template <class _Tp>
948inline weak_ptr<_Tp>::weak_ptr(weak_ptr const& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) {
949 if (__cntrl_)
950 __cntrl_->__add_weak();
951}
952
953template <class _Tp>
954template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> >
955inline weak_ptr<_Tp>::weak_ptr(shared_ptr<_Yp> const& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) {
956 if (__cntrl_)
957 __cntrl_->__add_weak();
958}
959
960template <class _Tp>
961template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> >
962inline weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp> const& __r) _NOEXCEPT : __ptr_(nullptr), __cntrl_(nullptr) {
963 shared_ptr<_Yp> __s = __r.lock();
964 *this = weak_ptr<_Tp>(__s);
965}
966
967template <class _Tp>
968inline weak_ptr<_Tp>::weak_ptr(weak_ptr&& __r) _NOEXCEPT : __ptr_(__r.__ptr_), __cntrl_(__r.__cntrl_) {
969 __r.__ptr_ = nullptr;
970 __r.__cntrl_ = nullptr;
971}
972
973template <class _Tp>
974template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> >
975inline weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp>&& __r) _NOEXCEPT : __ptr_(nullptr), __cntrl_(nullptr) {
976 shared_ptr<_Yp> __s = __r.lock();
977 *this = weak_ptr<_Tp>(__s);
978 __r.reset();
979}
980
981template <class _Tp>
982weak_ptr<_Tp>::~weak_ptr() {
983 if (__cntrl_)
984 __cntrl_->__release_weak();
985}
986
987template <class _Tp>
988inline weak_ptr<_Tp>& weak_ptr<_Tp>::operator=(weak_ptr const& __r) _NOEXCEPT {
989 weak_ptr(__r).swap(*this);
990 return *this;
991}
992
993template <class _Tp>
994template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> >
995inline weak_ptr<_Tp>& weak_ptr<_Tp>::operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT {
996 weak_ptr(__r).swap(*this);
997 return *this;
998}
999
1000template <class _Tp>
1001inline weak_ptr<_Tp>& weak_ptr<_Tp>::operator=(weak_ptr&& __r) _NOEXCEPT {
1002 weak_ptr(std::move(__r)).swap(*this);
1003 return *this;
1004}
1005
1006template <class _Tp>
1007template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> >
1008inline weak_ptr<_Tp>& weak_ptr<_Tp>::operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT {
1009 weak_ptr(std::move(__r)).swap(*this);
1010 return *this;
1011}
1012
1013template <class _Tp>
1014template <class _Yp, __enable_if_t<__compatible_with<_Yp, _Tp>::value, int> >
1015inline weak_ptr<_Tp>& weak_ptr<_Tp>::operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT {
1016 weak_ptr(__r).swap(*this);
1017 return *this;
1018}
1019
1020template <class _Tp>
1021inline void weak_ptr<_Tp>::swap(weak_ptr& __r) _NOEXCEPT {
1022 std::swap(__ptr_, __r.__ptr_);
1023 std::swap(__cntrl_, __r.__cntrl_);
1024}
1025
1026template <class _Tp>
1027inline _LIBCPP_HIDE_FROM_ABI void swap(weak_ptr<_Tp>& __x, weak_ptr<_Tp>& __y) _NOEXCEPT {
1028 __x.swap(__y);
1029}
1030
1031template <class _Tp>
1032inline void weak_ptr<_Tp>::reset() _NOEXCEPT {
1033 weak_ptr().swap(*this);
1034}
1035
1036template <class _Tp>
1037shared_ptr<_Tp> weak_ptr<_Tp>::lock() const _NOEXCEPT {
1038 shared_ptr<_Tp> __r;
1039 __r.__cntrl_ = __cntrl_ ? __cntrl_->lock() : __cntrl_;
1040 if (__r.__cntrl_)
1041 __r.__ptr_ = __ptr_;
1042 return __r;
1043}
1044
1045template <class _Tp>
1046struct owner_less;
1047
1048template <class _Tp>
1049struct _LIBCPP_TEMPLATE_VIS owner_less<shared_ptr<_Tp> > : __binary_function<shared_ptr<_Tp>, shared_ptr<_Tp>, bool> {
1050 _LIBCPP_HIDE_FROM_ABI bool operator()(shared_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT {
1051 return __x.owner_before(__y);
1052 }
1053 _LIBCPP_HIDE_FROM_ABI bool operator()(shared_ptr<_Tp> const& __x, weak_ptr<_Tp> const& __y) const _NOEXCEPT {
1054 return __x.owner_before(__y);
1055 }
1056 _LIBCPP_HIDE_FROM_ABI bool operator()(weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT {
1057 return __x.owner_before(__y);
1058 }
1059};
1060
1061template <class _Tp>
1062struct _LIBCPP_TEMPLATE_VIS owner_less<weak_ptr<_Tp> > : __binary_function<weak_ptr<_Tp>, weak_ptr<_Tp>, bool> {
1063 _LIBCPP_HIDE_FROM_ABI bool operator()(weak_ptr<_Tp> const& __x, weak_ptr<_Tp> const& __y) const _NOEXCEPT {
1064 return __x.owner_before(__y);
1065 }
1066 _LIBCPP_HIDE_FROM_ABI bool operator()(shared_ptr<_Tp> const& __x, weak_ptr<_Tp> const& __y) const _NOEXCEPT {
1067 return __x.owner_before(__y);
1068 }
1069 _LIBCPP_HIDE_FROM_ABI bool operator()(weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT {
1070 return __x.owner_before(__y);
1071 }
1072};
1073
1074template <class _Tp>
1075class _LIBCPP_TEMPLATE_VIS enable_shared_from_this {
1076 mutable weak_ptr<_Tp> __weak_this_;
1077
1078protected:
1079 _LIBCPP_HIDE_FROM_ABI enable_shared_from_this() _NOEXCEPT {}
1080 _LIBCPP_HIDE_FROM_ABI enable_shared_from_this(enable_shared_from_this const&) _NOEXCEPT {}
1081 _LIBCPP_HIDE_FROM_ABI enable_shared_from_this& operator=(enable_shared_from_this const&) _NOEXCEPT { return *this; }
1082 _LIBCPP_HIDE_FROM_ABI ~enable_shared_from_this() {}
1083
1084public:
1085 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> shared_from_this() { return shared_ptr<_Tp>(__weak_this_); }
1086 _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp const> shared_from_this() const { return shared_ptr<const _Tp>(__weak_this_); }
1087
1088 template <class _Up>
1089 friend class shared_ptr;
1090};
1091
1092template <class _Tp>
1093struct _LIBCPP_TEMPLATE_VIS hash;
1094
1095template <class _Tp>
1096struct _LIBCPP_TEMPLATE_VIS hash<shared_ptr<_Tp> > {
1097 typedef shared_ptr<_Tp> argument_type;
1098 typedef size_t result_type;
1099
1100 _LIBCPP_HIDE_FROM_ABI size_t operator()(const shared_ptr<_Tp>& __ptr) const _NOEXCEPT {
1101 return hash<typename shared_ptr<_Tp>::element_type*>()(__ptr.get());
1102 }
1103};
1104
1105template <class _CharT, class _Traits, class _Yp>
1106inline _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>&
1107operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p);
1108
1109#if !defined(_LIBCPP_HAS_NO_THREADS)
1110
1111class _LIBCPP_EXPORTED_FROM_ABI __sp_mut {
1112 void* __lx_;
1113
1114public:
1115 void lock() _NOEXCEPT;
1116 void unlock() _NOEXCEPT;
1117
1118private:
1119 __sp_mut(void*) _NOEXCEPT;
1120 __sp_mut(const __sp_mut&);
1121 __sp_mut& operator=(const __sp_mut&);
1122
1123 friend _LIBCPP_EXPORTED_FROM_ABI __sp_mut& __get_sp_mut(const void*);
1124};
1125
1126_LIBCPP_EXPORTED_FROM_ABI __sp_mut& __get_sp_mut(const void*);
1127
1128template <class _Tp>
1129inline _LIBCPP_HIDE_FROM_ABI bool atomic_is_lock_free(const shared_ptr<_Tp>*) {
1130 return false;
1131}
1132
1133template <class _Tp>
1134_LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> atomic_load(const shared_ptr<_Tp>* __p) {
1135 __sp_mut& __m = std::__get_sp_mut(__p);
1136 __m.lock();
1137 shared_ptr<_Tp> __q = *__p;
1138 __m.unlock();
1139 return __q;
1140}
1141
1142template <class _Tp>
1143inline _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> atomic_load_explicit(const shared_ptr<_Tp>* __p, memory_order) {
1144 return std::atomic_load(__p);
1145}
1146
1147template <class _Tp>
1148_LIBCPP_HIDE_FROM_ABI void atomic_store(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r) {
1149 __sp_mut& __m = std::__get_sp_mut(__p);
1150 __m.lock();
1151 __p->swap(__r);
1152 __m.unlock();
1153}
1154
1155template <class _Tp>
1156inline _LIBCPP_HIDE_FROM_ABI void atomic_store_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order) {
1157 std::atomic_store(__p, __r);
1158}
1159
1160template <class _Tp>
1161_LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp> atomic_exchange(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r) {
1162 __sp_mut& __m = std::__get_sp_mut(__p);
1163 __m.lock();
1164 __p->swap(__r);
1165 __m.unlock();
1166 return __r;
1167}
1168
1169template <class _Tp>
1170inline _LIBCPP_HIDE_FROM_ABI shared_ptr<_Tp>
1171atomic_exchange_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order) {
1172 return std::atomic_exchange(__p, __r);
1173}
1174
1175template <class _Tp>
1176_LIBCPP_HIDE_FROM_ABI bool
1177atomic_compare_exchange_strong(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w) {
1178 shared_ptr<_Tp> __temp;
1179 __sp_mut& __m = std::__get_sp_mut(__p);
1180 __m.lock();
1181 if (__p->__owner_equivalent(*__v)) {
1182 std::swap(__temp, *__p);
1183 *__p = __w;
1184 __m.unlock();
1185 return true;
1186 }
1187 std::swap(__temp, *__v);
1188 *__v = *__p;
1189 __m.unlock();
1190 return false;
1191}
1192
1193template <class _Tp>
1194inline _LIBCPP_HIDE_FROM_ABI bool
1195atomic_compare_exchange_weak(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w) {
1196 return std::atomic_compare_exchange_strong(__p, __v, __w);
1197}
1198
1199template <class _Tp>
1200inline _LIBCPP_HIDE_FROM_ABI bool atomic_compare_exchange_strong_explicit(
1201 shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w, memory_order, memory_order) {
1202 return std::atomic_compare_exchange_strong(__p, __v, __w);
1203}
1204
1205template <class _Tp>
1206inline _LIBCPP_HIDE_FROM_ABI bool atomic_compare_exchange_weak_explicit(
1207 shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w, memory_order, memory_order) {
1208 return std::atomic_compare_exchange_weak(__p, __v, __w);
1209}
1210
1211#endif // !defined(_LIBCPP_HAS_NO_THREADS)
1212
1213_LIBCPP_END_NAMESPACE_STD
1214
1215_LIBCPP_POP_MACROS
1216
1217#endif // _LIBCPP___CXX03___MEMORY_SHARED_PTR_H
1218

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source code of libcxx/include/__cxx03/__memory/shared_ptr.h