libstdc++
std::shared_ptr< _Tp > Class Template Reference

Inherits std::__shared_ptr< _Tp, _Lp >.

Public Types

using element_type = typename __shared_ptr< _Tp >::element_type
 

Public Member Functions

constexpr shared_ptr () noexcept
 
 shared_ptr (const shared_ptr &) noexcept=default
 
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 _Deleter >
 shared_ptr (nullptr_t __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 _Deleter , typename _Alloc >
 shared_ptr (nullptr_t __p, _Deleter __d, _Alloc __a)
 
template<typename _Yp >
 shared_ptr (const shared_ptr< _Yp > &__r, element_type *__p) noexcept
 
template<typename _Yp , typename = _Constructible<const shared_ptr<_Yp>&>>
 shared_ptr (const shared_ptr< _Yp > &__r) 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 , typename = _Constructible<const weak_ptr<_Yp>&>>
 shared_ptr (const weak_ptr< _Yp > &__r)
 
template<typename _Yp , typename _Del , typename = _Constructible<unique_ptr<_Yp, _Del>>>
 shared_ptr (unique_ptr< _Yp, _Del > &&__r)
 
constexpr shared_ptr (nullptr_t) noexcept
 
template<typename _Tp1 , typename >
 shared_ptr (std::auto_ptr< _Tp1 > &&__r)
 
element_type * get () const noexcept
 
 operator bool () const
 
element_type & operator* () const noexcept
 
element_type * operator-> () const noexcept
 
shared_ptroperator= (const shared_ptr &) noexcept=default
 
template<typename _Yp >
_Assignable< const shared_ptr< _Yp > & > operator= (const shared_ptr< _Yp > &__r) noexcept
 
shared_ptroperator= (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)
 
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
 
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
 

Friends

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

Detailed Description

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

A smart pointer with reference-counted copy semantics.

The object pointed to is deleted when the last shared_ptr pointing to it is destroyed or reset.

Definition at line 103 of file bits/shared_ptr.h.

Constructor & Destructor Documentation

◆ shared_ptr() [1/12]

template<typename _Tp>
constexpr std::shared_ptr< _Tp >::shared_ptr ( )
inlinenoexcept

Construct an empty shared_ptr.

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

Definition at line 127 of file bits/shared_ptr.h.

◆ shared_ptr() [2/12]

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
__pA pointer that is convertible to element_type*.
Postcondition
use_count() == 1 && get() == __p
Exceptions
std::bad_alloc,inwhich case delete __p is called.

Definition at line 139 of file bits/shared_ptr.h.

◆ shared_ptr() [3/12]

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
__pA pointer.
__dA deleter.
Postcondition
use_count() == 1 && get() == __p
Exceptions
std::bad_alloc,inwhich 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 156 of file bits/shared_ptr.h.

◆ shared_ptr() [4/12]

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
__pA null pointer constant.
__dA deleter.
Postcondition
use_count() == 1 && get() == __p
Exceptions
std::bad_alloc,inwhich 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 173 of file bits/shared_ptr.h.

◆ shared_ptr() [5/12]

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
__pA pointer.
__dA deleter.
__aAn allocator.
Postcondition
use_count() == 1 && get() == __p
Exceptions
std::bad_alloc,inwhich 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 193 of file bits/shared_ptr.h.

◆ shared_ptr() [6/12]

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
__pA null pointer constant.
__dA deleter.
__aAn allocator.
Postcondition
use_count() == 1 && get() == __p
Exceptions
std::bad_alloc,inwhich 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 212 of file bits/shared_ptr.h.

◆ shared_ptr() [7/12]

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
__rA shared_ptr.
__pA 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.

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 234 of file bits/shared_ptr.h.

◆ shared_ptr() [8/12]

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
__rA shared_ptr.
Postcondition
get() == __r.get() && use_count() == __r.use_count()

Definition at line 246 of file bits/shared_ptr.h.

◆ shared_ptr() [9/12]

template<typename _Tp>
std::shared_ptr< _Tp >::shared_ptr ( shared_ptr< _Tp > &&  __r)
inlinenoexcept

Move-constructs a shared_ptr instance from __r.

Parameters
__rA shared_ptr rvalue.
Postcondition
*this contains the old value of __r, __r is empty.

Definition at line 254 of file bits/shared_ptr.h.

◆ shared_ptr() [10/12]

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
__rA shared_ptr rvalue.
Postcondition
*this contains the old value of __r, __r is empty.

Definition at line 263 of file bits/shared_ptr.h.

◆ shared_ptr() [11/12]

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
__rA weak_ptr.
Postcondition
use_count() == __r.use_count()
Exceptions
bad_weak_ptrwhen __r.expired(), in which case the constructor has no effect.

Definition at line 275 of file bits/shared_ptr.h.

◆ shared_ptr() [12/12]

template<typename _Tp>
constexpr std::shared_ptr< _Tp >::shared_ptr ( nullptr_t  )
inlinenoexcept

Construct an empty shared_ptr.

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

Definition at line 307 of file bits/shared_ptr.h.

Friends And Related Function Documentation

◆ allocate_shared

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

Create an object that is owned by a shared_ptr.

Parameters
__aAn allocator.
__argsArguments for the _Tp object's constructor.
Returns
A shared_ptr that owns the newly created object.
Exceptions
Anexception thrown from _Alloc::allocate or from the constructor of _Tp.

A copy of __a will be used to allocate memory for the shared_ptr and the new object.

Definition at line 699 of file bits/shared_ptr.h.


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