Inherits std::__shared_ptr< _Tp, _Lp >.

Public Types
using	element_type = typename __shared_ptr< _Tp >::element_type

using	weak_type = weak_ptr< _Tp >

Public Member Functions
constexpr	shared_ptr () noexcept

template<typename _Yp , typename = _Constructible<_Yp*>>
	shared_ptr (_Yp *__p)

template<typename _Yp , typename _Deleter , typename = _Constructible<_Yp*, _Deleter>>
	shared_ptr (_Yp *__p, _Deleter __d)

template<typename _Yp , typename _Deleter , typename _Alloc , typename = _Constructible<_Yp*, _Deleter, _Alloc>>
	shared_ptr (_Yp *__p, _Deleter __d, _Alloc __a)

template<typename _Yp , typename = _Constructible<auto_ptr<_Yp>>>
	shared_ptr (auto_ptr< _Yp > &&__r)

	shared_ptr (const shared_ptr &) noexcept=default

template<typename _Yp , typename = _Constructible<const shared_ptr<_Yp>&>>
	shared_ptr (const shared_ptr< _Yp > &__r) noexcept

template<typename _Yp >
	shared_ptr (const shared_ptr< _Yp > &__r, element_type *__p) noexcept

template<typename _Yp , typename = _Constructible<const weak_ptr<_Yp>&>>
	shared_ptr (const weak_ptr< _Yp > &__r)

template<typename _Deleter >
	shared_ptr (nullptr_t __p, _Deleter __d)

template<typename _Deleter , typename _Alloc >
	shared_ptr (nullptr_t __p, _Deleter __d, _Alloc __a)

constexpr	shared_ptr (nullptr_t) noexcept

	shared_ptr (shared_ptr &&__r) noexcept

template<typename _Yp , typename = _Constructible<shared_ptr<_Yp>>>
	shared_ptr (shared_ptr< _Yp > &&__r) noexcept

template<typename _Yp >
	shared_ptr (shared_ptr< _Yp > &&__r, element_type *__p) noexcept

template<typename _Tp1 , typename >
	shared_ptr (std::auto_ptr< _Tp1 > &&__r)

template<typename _Yp , typename _Del , typename = _Constructible<unique_ptr<_Yp, _Del>>>
	shared_ptr (unique_ptr< _Yp, _Del > &&__r)

element_type *	get () const noexcept

	operator bool () const noexcept

element_type &	operator* () const noexcept

element_type *	operator-> () const noexcept

template<typename _Yp >
_Assignable< auto_ptr< _Yp > >	operator= (auto_ptr< _Yp > &&__r)

shared_ptr &	operator= (const shared_ptr &) noexcept=default

template<typename _Yp >
_Assignable< const shared_ptr< _Yp > & >	operator= (const shared_ptr< _Yp > &__r) noexcept

shared_ptr &	operator= (shared_ptr &&__r) noexcept

template<class _Yp >
_Assignable< shared_ptr< _Yp > >	operator= (shared_ptr< _Yp > &&__r) noexcept

template<typename _Yp , typename _Del >
_Assignable< unique_ptr< _Yp, _Del > >	operator= (unique_ptr< _Yp, _Del > &&__r)

void	reset () noexcept

template<typename _Yp >
_SafeConv< _Yp >	reset (_Yp *__p)

template<typename _Yp , typename _Deleter >
_SafeConv< _Yp >	reset (_Yp *__p, _Deleter __d)

template<typename _Yp , typename _Deleter , typename _Alloc >
_SafeConv< _Yp >	reset (_Yp *__p, _Deleter __d, _Alloc __a)

void	swap (__shared_ptr< _Tp, _Lp > &__other) noexcept

bool	unique () const noexcept

long	use_count () const noexcept


template<typename _Tp1 >
bool	owner_before (__shared_ptr< _Tp1, _Lp > const &__rhs) const noexcept

template<typename _Tp1 >
bool	owner_before (__weak_ptr< _Tp1, _Lp > const &__rhs) const noexcept

Friends
template<typename _Yp , typename _Alloc >
shared_ptr< _BoundedArray< _Yp > >	allocate_shared (const _Alloc &)

template<typename _Yp , typename _Alloc , typename... _Args>
shared_ptr< _NonArray< _Yp > >	allocate_shared (const _Alloc &, _Args &&...)

template<typename _Yp , typename _Alloc >
shared_ptr< _BoundedArray< _Yp > >	allocate_shared (const _Alloc &, const remove_extent_t< _Yp > &)

template<typename _Yp , typename _Alloc >
shared_ptr< _UnboundedArray< _Yp > >	allocate_shared (const _Alloc &, size_t)

template<typename _Yp , typename _Alloc >
shared_ptr< _UnboundedArray< _Yp > >	allocate_shared (const _Alloc &, size_t, const remove_extent_t< _Yp > &)

template<typename _Yp , typename _Alloc >
shared_ptr< _NotUnboundedArray< _Yp > >	allocate_shared_for_overwrite (const _Alloc &)

template<typename _Yp , typename _Alloc >
shared_ptr< _UnboundedArray< _Yp > >	allocate_shared_for_overwrite (const _Alloc &, size_t)

template<typename _Yp >
shared_ptr< _BoundedArray< _Yp > >	make_shared ()

template<typename _Yp , typename... _Args>
shared_ptr< _NonArray< _Yp > >	make_shared (_Args &&...)

template<typename _Yp >
shared_ptr< _BoundedArray< _Yp > >	make_shared (const remove_extent_t< _Yp > &)

template<typename _Yp >
shared_ptr< _UnboundedArray< _Yp > >	make_shared (size_t)

template<typename _Yp >
shared_ptr< _UnboundedArray< _Yp > >	make_shared (size_t, const remove_extent_t< _Yp > &)

template<typename _Yp >
shared_ptr< _NotUnboundedArray< _Yp > >	make_shared_for_overwrite ()

template<typename _Yp >
shared_ptr< _UnboundedArray< _Yp > >	make_shared_for_overwrite (size_t)

class	weak_ptr< _Tp >

Related Functions
(Note that these are not member functions.)
template<typename _Del , typename _Tp >
_Del *	get_deleter (const shared_ptr< _Tp > &__p) noexcept

template<typename _Ch , typename _Tr , typename _Tp , _Lock_policy _Lp>
std::basic_ostream< _Ch, _Tr > &	operator<< (std::basic_ostream< _Ch, _Tr > &__os, const __shared_ptr< _Tp, _Lp > &__p)


template<typename _Tp , typename _Up >
bool	operator== (const shared_ptr< _Tp > &__a, const shared_ptr< _Up > &__b) noexcept

template<typename _Tp >
bool	operator== (const shared_ptr< _Tp > &__a, nullptr_t) noexcept

template<typename _Tp >
bool	operator== (nullptr_t, const shared_ptr< _Tp > &__a) noexcept

template<typename _Tp , typename _Up >
bool	operator!= (const shared_ptr< _Tp > &__a, const shared_ptr< _Up > &__b) noexcept

template<typename _Tp >
bool	operator!= (const shared_ptr< _Tp > &__a, nullptr_t) noexcept

template<typename _Tp >
bool	operator!= (nullptr_t, const shared_ptr< _Tp > &__a) noexcept

template<typename _Tp , typename _Up >
bool	operator< (const shared_ptr< _Tp > &__a, const shared_ptr< _Up > &__b) noexcept

template<typename _Tp >
bool	operator< (const shared_ptr< _Tp > &__a, nullptr_t) noexcept

template<typename _Tp >
bool	operator< (nullptr_t, const shared_ptr< _Tp > &__a) noexcept

template<typename _Tp , typename _Up >
bool	operator<= (const shared_ptr< _Tp > &__a, const shared_ptr< _Up > &__b) noexcept

template<typename _Tp >
bool	operator<= (const shared_ptr< _Tp > &__a, nullptr_t) noexcept

template<typename _Tp >
bool	operator<= (nullptr_t, const shared_ptr< _Tp > &__a) noexcept

template<typename _Tp , typename _Up >
bool	operator> (const shared_ptr< _Tp > &__a, const shared_ptr< _Up > &__b) noexcept

template<typename _Tp >
bool	operator> (const shared_ptr< _Tp > &__a, nullptr_t) noexcept

template<typename _Tp >
bool	operator> (nullptr_t, const shared_ptr< _Tp > &__a) noexcept

template<typename _Tp , typename _Up >
bool	operator>= (const shared_ptr< _Tp > &__a, const shared_ptr< _Up > &__b) noexcept

template<typename _Tp >
bool	operator>= (const shared_ptr< _Tp > &__a, nullptr_t) noexcept

template<typename _Tp >
bool	operator>= (nullptr_t, const shared_ptr< _Tp > &__a) noexcept

template<typename _Tp >
void	swap (shared_ptr< _Tp > &__a, shared_ptr< _Tp > &__b) noexcept

template<typename _Tp , typename _Up >
shared_ptr< _Tp >	static_pointer_cast (const shared_ptr< _Up > &__r) noexcept

template<typename _Tp , typename _Up >
shared_ptr< _Tp >	const_pointer_cast (const shared_ptr< _Up > &__r) noexcept

template<typename _Tp , typename _Up >
shared_ptr< _Tp >	dynamic_pointer_cast (const shared_ptr< _Up > &__r) noexcept

template<typename _Tp , typename _Up >
shared_ptr< _Tp >	reinterpret_pointer_cast (const shared_ptr< _Up > &__r) noexcept

template<typename _Tp , typename _Up >
shared_ptr< _Tp >	static_pointer_cast (shared_ptr< _Up > &&__r) noexcept

template<typename _Tp , typename _Up >
shared_ptr< _Tp >	const_pointer_cast (shared_ptr< _Up > &&__r) noexcept

template<typename _Tp , typename _Up >
shared_ptr< _Tp >	dynamic_pointer_cast (shared_ptr< _Up > &&__r) noexcept

template<typename _Tp , typename _Up >
shared_ptr< _Tp >	reinterpret_pointer_cast (shared_ptr< _Up > &&__r) noexcept


template<typename _Tp , typename _Alloc , typename... _Args>
shared_ptr< _NonArray< _Tp > >	allocate_shared (const _Alloc &__a, _Args &&... __args)

template<typename _Tp , typename... _Args>
shared_ptr< _NonArray< _Tp > >	make_shared (_Args &&... __args)

template<typename _Tp , typename _Alloc >
shared_ptr< _UnboundedArray< _Tp > >	allocate_shared (const _Alloc &__a, size_t __n)

template<typename _Tp , typename _Alloc >
shared_ptr< _BoundedArray< _Tp > >	allocate_shared (const _Alloc &__a)


template<typename _Tp , _Lock_policy _Lp>
bool	atomic_is_lock_free (const __shared_ptr< _Tp, _Lp > *__p)


template<typename _Tp >
shared_ptr< _Tp >	atomic_load_explicit (const shared_ptr< _Tp > *__p, memory_order)


template<typename _Tp >
void	atomic_store_explicit (shared_ptr< _Tp > *__p, shared_ptr< _Tp > __r, memory_order)


template<typename _Tp >
shared_ptr< _Tp >	atomic_exchange_explicit (shared_ptr< _Tp > *__p, shared_ptr< _Tp > __r, memory_order)


template<typename _Tp >
bool	atomic_compare_exchange_strong_explicit (shared_ptr< _Tp > __p, shared_ptr< _Tp > __v, shared_ptr< _Tp > __w, memory_order, memory_order)

Detailed Description

template<typename _Tp>
class std::shared_ptr< _Tp >

A smart pointer with reference-counted copy semantics.

Since: C++11

A shared_ptr object is either empty or owns a pointer passed to the constructor. Copies of a shared_ptr share ownership of the same pointer. When the last shared_ptr that owns the pointer is destroyed or reset, the owned pointer is freed (either by delete or by invoking a custom deleter that was passed to the constructor).

A shared_ptr also stores another pointer, which is usually (but not always) the same pointer as it owns. The stored pointer can be retrieved by calling the get() member function.

The equality and relational operators for shared_ptr only compare the stored pointer returned by get(), not the owned pointer. To test whether two shared_ptr objects share ownership of the same pointer see std::shared_ptr::owner_before and std::owner_less.

Definition at line 175 of file bits/shared_ptr.h.

Member Typedef Documentation

◆ element_type

template<typename _Tp >

using std::shared_ptr< _Tp >::element_type = typename __shared_ptr<_Tp>::element_type

The type pointed to by the stored pointer, remove_extent_t<_Tp>

Definition at line 190 of file bits/shared_ptr.h.

◆ weak_type

template<typename _Tp >

using std::shared_ptr< _Tp >::weak_type = weak_ptr<_Tp>

The corresponding weak_ptr type for this shared_ptr.

Since: C++17

Definition at line 196 of file bits/shared_ptr.h.

Constructor & Destructor Documentation

◆ shared_ptr() [1/14]

template<typename _Tp >

constexpr std::shared_ptr< _Tp >::shared_ptr ( )

inlineconstexprnoexcept

Construct an empty shared_ptr.

Postcondition: use_count()==0 && get()==0

Definition at line 202 of file bits/shared_ptr.h.

◆ shared_ptr() [2/14]

template<typename _Tp >

std::shared_ptr< _Tp >::shared_ptr ( const shared_ptr< _Tp > & )

defaultnoexcept

Copy constructor.

◆ shared_ptr() [3/14]

template<typename _Tp >

template<typename _Yp , typename = _Constructible<_Yp*>>

std::shared_ptr< _Tp >::shared_ptr ( _Yp * __p )

inlineexplicit

Construct a shared_ptr that owns the pointer __p.

Parameters

__p	A pointer that is convertible to element_type*.

Postcondition: use_count() == 1 && get() == __p

Exceptions

std::bad_alloc,in which case delete __p is called.

Definition at line 214 of file bits/shared_ptr.h.

◆ shared_ptr() [4/14]

template<typename _Tp >

template<typename _Yp , typename _Deleter , typename = _Constructible<_Yp*, _Deleter>>

std::shared_ptr< _Tp >::shared_ptr	(	_Yp *	__p,
		_Deleter	__d
	)

inline

Construct a shared_ptr that owns the pointer __p and the deleter __d.

Parameters

__p	A pointer.
__d	A deleter.

Postcondition: use_count() == 1 && get() == __p

Exceptions

std::bad_alloc,in which case __d(__p) is called.

Requirements: _Deleter's copy constructor and destructor must not throw

__shared_ptr will release __p by calling __d(__p)

Definition at line 231 of file bits/shared_ptr.h.

◆ shared_ptr() [5/14]

template<typename _Tp >

template<typename _Deleter >

std::shared_ptr< _Tp >::shared_ptr	(	nullptr_t	__p,
		_Deleter	__d
	)

inline

Construct a shared_ptr that owns a null pointer and the deleter __d.

Parameters

__p	A null pointer constant.
__d	A deleter.

Postcondition: use_count() == 1 && get() == __p

Exceptions

std::bad_alloc,in which case __d(__p) is called.

Requirements: _Deleter's copy constructor and destructor must not throw

The last owner will call __d(__p)

Definition at line 248 of file bits/shared_ptr.h.

◆ shared_ptr() [6/14]

template<typename _Tp >

template<typename _Yp , typename _Deleter , typename _Alloc , typename = _Constructible<_Yp*, _Deleter, _Alloc>>

std::shared_ptr< _Tp >::shared_ptr	(	_Yp *	__p,
		_Deleter	__d,
		_Alloc	__a
	)

inline

Construct a shared_ptr that owns the pointer __p and the deleter __d.

Parameters

__p	A pointer.
__d	A deleter.
__a	An allocator.

Postcondition: use_count() == 1 && get() == __p

Exceptions

std::bad_alloc,in which case __d(__p) is called.

Requirements: _Deleter's copy constructor and destructor must not throw _Alloc's copy constructor and destructor must not throw.

__shared_ptr will release __p by calling __d(__p)

Definition at line 268 of file bits/shared_ptr.h.

◆ shared_ptr() [7/14]

template<typename _Tp >

template<typename _Deleter , typename _Alloc >

std::shared_ptr< _Tp >::shared_ptr	(	nullptr_t	__p,
		_Deleter	__d,
		_Alloc	__a
	)

inline

Construct a shared_ptr that owns a null pointer and the deleter __d.

Parameters

__p	A null pointer constant.
__d	A deleter.
__a	An allocator.

Postcondition: use_count() == 1 && get() == __p

Exceptions

std::bad_alloc,in which case __d(__p) is called.

Requirements: _Deleter's copy constructor and destructor must not throw _Alloc's copy constructor and destructor must not throw.

The last owner will call __d(__p)

Definition at line 287 of file bits/shared_ptr.h.

◆ shared_ptr() [8/14]

template<typename _Tp >

template<typename _Yp >

std::shared_ptr< _Tp >::shared_ptr	(	const shared_ptr< _Yp > &	__r,
		element_type *	__p
	)

inlinenoexcept

Constructs a shared_ptr instance that stores __p and shares ownership with __r.

Parameters

__r	A `shared_ptr`.
__p	A pointer that will remain valid while `*__r` is valid.

Postcondition: get() == __p && use_count() == __r.use_count()

This can be used to construct a shared_ptr to a sub-object of an object managed by an existing shared_ptr. The complete object will remain valid while any shared_ptr owns it, even if they don't store a pointer to the complete object.

shared_ptr<pair<int,int>> pii(new pair<int,int>());
shared_ptr<int> pi(pii, &pii->first);
assert(pii.use_count() == 2);

Definition at line 311 of file bits/shared_ptr.h.

◆ shared_ptr() [9/14]

template<typename _Tp >

template<typename _Yp >

std::shared_ptr< _Tp >::shared_ptr	(	shared_ptr< _Yp > &&	__r,
		element_type *	__p
	)

inlinenoexcept

Constructs a shared_ptr instance that stores __p and shares ownership with __r.

Parameters

__r	A `shared_ptr`.
__p	A pointer that will remain valid while `*__r` is valid.

Postcondition: get() == __p && !__r.use_count() && !__r.get()

Since: C++17

This can be used to construct a shared_ptr to a sub-object of an object managed by an existing shared_ptr. The complete object will remain valid while any shared_ptr owns it, even if they don't store a pointer to the complete object.

shared_ptr<pair<int,int>> pii(new pair<int,int>());
shared_ptr<int> pi1(pii, &pii->first);
assert(pii.use_count() == 2);
shared_ptr<int> pi2(std::move(pii), &pii->second);
assert(pii.use_count() == 0);

Definition at line 339 of file bits/shared_ptr.h.

◆ shared_ptr() [10/14]

template<typename _Tp >

template<typename _Yp , typename = _Constructible<const shared_ptr<_Yp>&>>

std::shared_ptr< _Tp >::shared_ptr ( const shared_ptr< _Yp > & __r )

inlinenoexcept

If __r is empty, constructs an empty shared_ptr; otherwise construct a shared_ptr that shares ownership with __r.

Parameters

__r	A shared_ptr.

Postcondition: get() == __r.get() && use_count() == __r.use_count()

Definition at line 351 of file bits/shared_ptr.h.

◆ shared_ptr() [11/14]

template<typename _Tp >

std::shared_ptr< _Tp >::shared_ptr ( shared_ptr< _Tp > && __r )

inlinenoexcept

Move-constructs a shared_ptr instance from __r.

Parameters

__r	A shared_ptr rvalue.

Postcondition: *this contains the old value of __r, __r is empty.

Definition at line 359 of file bits/shared_ptr.h.

◆ shared_ptr() [12/14]

template<typename _Tp >

template<typename _Yp , typename = _Constructible<shared_ptr<_Yp>>>

std::shared_ptr< _Tp >::shared_ptr ( shared_ptr< _Yp > && __r )

inlinenoexcept

Move-constructs a shared_ptr instance from __r.

Parameters

__r	A shared_ptr rvalue.

Postcondition: *this contains the old value of __r, __r is empty.

Definition at line 368 of file bits/shared_ptr.h.

◆ shared_ptr() [13/14]

template<typename _Tp >

template<typename _Yp , typename = _Constructible<const weak_ptr<_Yp>&>>

std::shared_ptr< _Tp >::shared_ptr ( const weak_ptr< _Yp > & __r )

inlineexplicit

Constructs a shared_ptr that shares ownership with __r and stores a copy of the pointer stored in __r.

Parameters

__r	A weak_ptr.

Postcondition: use_count() == __r.use_count()

Exceptions

bad_weak_ptr when __r.expired(), in which case the constructor has no effect.

Definition at line 380 of file bits/shared_ptr.h.

◆ shared_ptr() [14/14]

template<typename _Tp >

constexpr std::shared_ptr< _Tp >::shared_ptr ( nullptr_t )

inlineconstexprnoexcept

Construct an empty shared_ptr.

Postcondition: use_count() == 0 && get() == nullptr

Definition at line 412 of file bits/shared_ptr.h.

Member Function Documentation

◆ get()

template<typename _Tp , _Lock_policy _Lp>

element_type* std::__shared_ptr< _Tp, _Lp >::get ( void ) const

inlinenoexceptinherited

Return the stored pointer.

Definition at line 1665 of file shared_ptr_base.h.

◆ operator bool()

template<typename _Tp , _Lock_policy _Lp>

std::__shared_ptr< _Tp, _Lp >::operator bool ( ) const

inlineexplicitnoexceptinherited

Return true if the stored pointer is not null.

Definition at line 1669 of file shared_ptr_base.h.

◆ owner_before() [1/2]

template<typename _Tp , _Lock_policy _Lp>

template<typename _Tp1 >

bool std::__shared_ptr< _Tp, _Lp >::owner_before ( __shared_ptr< _Tp1, _Lp > const & __rhs ) const

inlinenoexceptinherited

Define an ordering based on ownership.

This function defines a strict weak ordering between two shared_ptr or weak_ptr objects, such that one object is less than the other unless they share ownership of the same pointer, or are both empty.

Definition at line 1699 of file shared_ptr_base.h.

◆ owner_before() [2/2]

template<typename _Tp , _Lock_policy _Lp>

template<typename _Tp1 >

bool std::__shared_ptr< _Tp, _Lp >::owner_before ( __weak_ptr< _Tp1, _Lp > const & __rhs ) const

inlinenoexceptinherited

Define an ordering based on ownership.

This function defines a strict weak ordering between two shared_ptr or weak_ptr objects, such that one object is less than the other unless they share ownership of the same pointer, or are both empty.

Definition at line 1704 of file shared_ptr_base.h.

◆ swap()

template<typename _Tp , _Lock_policy _Lp>

void std::__shared_ptr< _Tp, _Lp >::swap ( __shared_ptr< _Tp, _Lp > & __other )

inlinenoexceptinherited

Exchange both the owned pointer and the stored pointer.

Definition at line 1684 of file shared_ptr_base.h.

◆ unique()

template<typename _Tp , _Lock_policy _Lp>

bool std::__shared_ptr< _Tp, _Lp >::unique ( ) const

inlinenoexceptinherited

Return true if use_count() == 1.

Definition at line 1674 of file shared_ptr_base.h.

◆ use_count()

template<typename _Tp , _Lock_policy _Lp>

long std::__shared_ptr< _Tp, _Lp >::use_count ( ) const

inlinenoexceptinherited

If *this owns a pointer, return the number of owners, otherwise zero.

Definition at line 1679 of file shared_ptr_base.h.

The documentation for this class was generated from the following files:

Public Types

Public Member Functions

Friends

Related Functions

Detailed Description

template<typename _Tp> class std::shared_ptr< _Tp >

Member Typedef Documentation

◆ element_type

◆ weak_type

Constructor & Destructor Documentation

◆ shared_ptr() [1/14]

◆ shared_ptr() [2/14]

◆ shared_ptr() [3/14]

◆ shared_ptr() [4/14]

◆ shared_ptr() [5/14]

◆ shared_ptr() [6/14]

◆ shared_ptr() [7/14]

◆ shared_ptr() [8/14]

◆ shared_ptr() [9/14]

◆ shared_ptr() [10/14]

◆ shared_ptr() [11/14]

◆ shared_ptr() [12/14]

◆ shared_ptr() [13/14]

◆ shared_ptr() [14/14]

Member Function Documentation

◆ get()

◆ operator bool()

◆ owner_before() [1/2]

◆ owner_before() [2/2]

◆ swap()

◆ unique()

◆ use_count()

template<typename _Tp>
class std::shared_ptr< _Tp >