\inmodule QtCore More...

#include <qsharedpointer_impl.h>

Collaboration diagram for QWeakPointer< T >:

Public Types
typedef T	element_type

typedef T	value_type

typedef value_type *	pointer

typedef const value_type *	const_pointer

typedef value_type &	reference

typedef const value_type &	const_reference

typedef qptrdiff	difference_type

Public Member Functions
bool	isNull () const noexcept
	Returns `true` if this object refers to \nullptr.

	operator bool () const noexcept
	Returns `true` if the contained pointer is not \nullptr.

bool	operator! () const noexcept
	Returns `true` if this object refers to \nullptr.

Q_NODISCARD_CTOR constexpr	QWeakPointer () noexcept

	~QWeakPointer ()
	Destroys this QWeakPointer object.

Q_NODISCARD_CTOR	QWeakPointer (const QWeakPointer &other) noexcept
	Creates a QWeakPointer that holds a weak reference to the pointer referenced by other.

Q_NODISCARD_CTOR	QWeakPointer (QWeakPointer &&other) noexcept

template<class X , IfCompatible< X > = true>
Q_NODISCARD_CTOR	QWeakPointer (QWeakPointer< X > &&other) noexcept

template<class X , IfCompatible< X > = true>
QWeakPointer &	operator= (QWeakPointer< X > &&other) noexcept

QWeakPointer &	operator= (const QWeakPointer &other) noexcept
	Makes this object share other's pointer.

void	swap (QWeakPointer &other) noexcept

Q_NODISCARD_CTOR	QWeakPointer (const QSharedPointer< T > &o)
	Creates a QWeakPointer that holds a weak reference to the pointer referenced by other.

QWeakPointer &	operator= (const QSharedPointer< T > &o)
	Makes this object share other's pointer.

template<class X , IfCompatible< X > = true>
Q_NODISCARD_CTOR	QWeakPointer (const QWeakPointer< X > &o)

template<class X , IfCompatible< X > = true>
QWeakPointer &	operator= (const QWeakPointer< X > &o)

template<class X , IfCompatible< X > = true>
Q_NODISCARD_CTOR	QWeakPointer (const QSharedPointer< X > &o)

template<class X , IfCompatible< X > = true>
QWeakPointer &	operator= (const QSharedPointer< X > &o)

void	clear ()
	Clears this QWeakPointer object, dropping the reference that it may have had to the pointer.

QSharedPointer< T >	toStrongRef () const
	Promotes this weak reference to a strong one and returns a QSharedPointer object holding that reference.

QSharedPointer< T >	lock () const

template<class X >
bool	operator== (const QWeakPointer< X > &o) const noexcept

template<class X >
bool	operator!= (const QWeakPointer< X > &o) const noexcept

template<class X >
bool	operator== (const QSharedPointer< X > &o) const noexcept

template<class X >
bool	operator!= (const QSharedPointer< X > &o) const noexcept

Friends
struct	QtPrivate::EnableInternalData

template<class X >
class	QSharedPointer

template<class X >
class	QWeakPointer
	Creates a QWeakPointer that points to nothing.

template<class X >
class	QPointer

template<typename X >
bool	operator== (const QSharedPointer< X > &p1, const QWeakPointer &p2) noexcept

template<typename X >
bool	operator!= (const QSharedPointer< X > &p1, const QWeakPointer &p2) noexcept

bool	operator== (const QWeakPointer &p, std::nullptr_t)

bool	operator== (std::nullptr_t, const QWeakPointer &p)

bool	operator!= (const QWeakPointer &p, std::nullptr_t)

bool	operator!= (std::nullptr_t, const QWeakPointer &p)

Related Symbols
(Note that these are not member symbols.)
template< class T > template< class X > bool	operator== (const QSharedPointer< T > &ptr1, const QWeakPointer< X > &ptr2)
	Returns `true` if ptr1 and ptr2 refer to the same pointer.

template< class T > template< class X > bool	operator!= (const QSharedPointer< T > &ptr1, const QWeakPointer< X > &ptr2)
	Returns `true` if ptr1 and ptr2 refer to distinct pointers.

template< class T > template< class X > bool	operator== (const QWeakPointer< T > &ptr1, const QSharedPointer< X > &ptr2)
	Returns `true` if ptr1 and ptr2 refer to the same pointer.

template< class T > bool	operator== (const QWeakPointer< T > &lhs, std::nullptr_t)

template< class T > bool	operator== (std::nullptr_t, const QWeakPointer< T > &rhs)

template< class T > bool	operator!= (const QWeakPointer< T > &lhs, std::nullptr_t)

template< class T > bool	operator!= (std::nullptr_t, const QWeakPointer< T > &rhs)

template< class T > template< class X > bool	operator!= (const QWeakPointer< T > &ptr1, const QSharedPointer< X > &ptr2)
	Returns `true` if ptr1 and ptr2 refer to distinct pointers.

template< class X > template< class T > QSharedPointer< X >	qSharedPointerCast (const QWeakPointer< T > &other)
	Returns a shared pointer to the pointer held by other, cast to type \tt X.

template< class X > template< class T > QSharedPointer< X >	qSharedPointerDynamicCast (const QWeakPointer< T > &src)
	Returns a shared pointer to the pointer held by src, using a dynamic cast to type \tt X to obtain an internal pointer of the appropriate type.

template< class X > template< class T > QSharedPointer< X >	qSharedPointerConstCast (const QWeakPointer< T > &src)
	Returns a shared pointer to the pointer held by src, cast to type \tt X.

template< class X > template< class T > QSharedPointer< X >	qSharedPointerObjectCast (const QWeakPointer< T > &src)
	The qSharedPointerObjectCast function is for casting a shared pointer.

template< class X > template< class T > QWeakPointer< X >	qWeakPointerCast (const QWeakPointer< T > &src)
	Returns a weak pointer to the pointer held by src, cast to type \tt X.

Detailed Description

template<class T>
class QWeakPointer< T >

\inmodule QtCore

The QWeakPointer class holds a weak reference to a shared pointer.

Since: 4.5 \reentrant

The QWeakPointer is an automatic weak reference to a pointer in C++. It cannot be used to dereference the pointer directly, but it can be used to verify if the pointer has been deleted or not in another context.

QWeakPointer objects can only be created by assignment from a QSharedPointer.

It's important to note that QWeakPointer provides no automatic casting operators to prevent mistakes from happening. Even though QWeakPointer tracks a pointer, it should not be considered a pointer itself, since it doesn't guarantee that the pointed object remains valid.

Therefore, to access the pointer that QWeakPointer is tracking, you must first promote it to QSharedPointer and verify if the resulting object is null or not. QSharedPointer guarantees that the object isn't deleted, so if you obtain a non-null object, you may use the pointer. See QWeakPointer::toStrongRef() for an example.

\omit

Definition at line 534 of file qsharedpointer_impl.h.

Member Typedef Documentation

◆ const_pointer

template<class T >

typedef const value_type* QWeakPointer< T >::const_pointer

Definition at line 544 of file qsharedpointer_impl.h.

◆ const_reference

template<class T >

typedef const value_type& QWeakPointer< T >::const_reference

Definition at line 546 of file qsharedpointer_impl.h.

◆ difference_type

template<class T >

typedef qptrdiff QWeakPointer< T >::difference_type

Definition at line 547 of file qsharedpointer_impl.h.

◆ element_type

template<class T >

typedef T QWeakPointer< T >::element_type

Definition at line 541 of file qsharedpointer_impl.h.

◆ pointer

template<class T >

typedef value_type* QWeakPointer< T >::pointer

Definition at line 543 of file qsharedpointer_impl.h.

◆ reference

template<class T >

typedef value_type& QWeakPointer< T >::reference

Definition at line 545 of file qsharedpointer_impl.h.

◆ value_type

template<class T >

typedef T QWeakPointer< T >::value_type

Definition at line 542 of file qsharedpointer_impl.h.

Constructor & Destructor Documentation

◆ QWeakPointer() [1/7]

template<class T >

Q_NODISCARD_CTOR constexpr QWeakPointer< T >::QWeakPointer ( )

inlineconstexprnoexcept

Definition at line 554 of file qsharedpointer_impl.h.

◆ ~QWeakPointer()

template<class T >

template< class T > QWeakPointer< T >::~QWeakPointer ( )

inline

Destroys this QWeakPointer object.

The pointer referenced by this object will not be deleted.

Definition at line 555 of file qsharedpointer_impl.h.

References QBasicAtomicInteger< T >::deref(), and QtSharedPointer::ExternalRefCountData::weakref.

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◆ QWeakPointer() [2/7]

template<class T >

template< class T > QWeakPointer< T >::QWeakPointer ( const QWeakPointer< T > & other )

inlinenoexcept

Creates a QWeakPointer that holds a weak reference to the pointer referenced by other.

If \tt T is a derived type of the template parameter of this class, QWeakPointer will perform an automatic cast. Otherwise, you will get a compiler error.

Definition at line 558 of file qsharedpointer_impl.h.

References QBasicAtomicInteger< T >::ref(), and QtSharedPointer::ExternalRefCountData::weakref.

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◆ QWeakPointer() [3/7]

template<class T >

Q_NODISCARD_CTOR QWeakPointer< T >::QWeakPointer ( QWeakPointer< T > && other )

inlinenoexcept

Definition at line 561 of file qsharedpointer_impl.h.

References other().

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◆ QWeakPointer() [4/7]

template<class T >

template<class X , IfCompatible< X > = true>

Q_NODISCARD_CTOR QWeakPointer< T >::QWeakPointer ( QWeakPointer< X > && other )

inlinenoexcept

Definition at line 571 of file qsharedpointer_impl.h.

References other().

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◆ QWeakPointer() [5/7]

template<class T >

template< class T > QWeakPointer< T >::QWeakPointer ( const QSharedPointer< T > & other )

inline

Creates a QWeakPointer that holds a weak reference to the pointer referenced by other.

If \tt T is a derived type of the template parameter of this class, QWeakPointer will perform an automatic cast. Otherwise, you will get a compiler error.

Definition at line 600 of file qsharedpointer_impl.h.

References QBasicAtomicInteger< T >::ref(), and QtSharedPointer::ExternalRefCountData::weakref.

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◆ QWeakPointer() [6/7]

template<class T >

template<class X , IfCompatible< X > = true>

Q_NODISCARD_CTOR QWeakPointer< T >::QWeakPointer ( const QWeakPointer< X > & o )

inline

Definition at line 610 of file qsharedpointer_impl.h.

References o.

◆ QWeakPointer() [7/7]

template<class T >

template<class X , IfCompatible< X > = true>

Q_NODISCARD_CTOR QWeakPointer< T >::QWeakPointer ( const QSharedPointer< X > & o )

inline

Definition at line 624 of file qsharedpointer_impl.h.

References o.

Member Function Documentation

◆ clear()

template<class T >

template< class T > void QWeakPointer< T >::clear ( )

inline

Clears this QWeakPointer object, dropping the reference that it may have had to the pointer.

Definition at line 634 of file qsharedpointer_impl.h.

References QWeakPointer< T >::QWeakPointer.

Referenced by QPointer< T >::clear().

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◆ isNull()

template<class T >

template< class T > bool QWeakPointer< T >::isNull ( ) const

inlinenoexcept

Returns true if this object refers to \nullptr.

Note that, due to the nature of weak references, the pointer that QWeakPointer references can become \nullptr at any moment, so the value returned from this function can change from false to true from one call to the next.

Definition at line 549 of file qsharedpointer_impl.h.

References QBasicAtomicInteger< T >::loadRelaxed(), and QtSharedPointer::ExternalRefCountData::strongref.

Referenced by QPointer< T >::isNull(), QWeakPointer< T >::operator bool(), and QWeakPointer< T >::operator!().

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◆ lock()

template<class T >

template< class T > QSharedPointer< T > QWeakPointer< T >::lock ( ) const

inline

Since: 5.4

Same as toStrongRef().

This function is provided for API compatibility with std::weak_ptr.

Definition at line 638 of file qsharedpointer_impl.h.

References QWeakPointer< T >::toStrongRef().

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◆ operator bool()

template<class T >

template< class T > QWeakPointer< T >::operator bool ( ) const

inlineexplicitnoexcept

Returns true if the contained pointer is not \nullptr.

This function is suitable for use in \tt if-constructs, like:

if (weakref) { ... }

weakref

QWeakPointer< int > weakref

[10]

Definition src_corelib_tools_qsharedpointer.cpp:90

Note that, due to the nature of weak references, the pointer that QWeakPointer references can become \nullptr at any moment, so the value returned from this function can change from true to false from one call to the next.

See also: isNull()

Definition at line 550 of file qsharedpointer_impl.h.

References QWeakPointer< T >::isNull().

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◆ operator!()

template<class T >

template< class T > bool QWeakPointer< T >::operator! ( ) const

inlinenoexcept

Returns true if this object refers to \nullptr.

This function is suitable for use in \tt if-constructs, like:

if (!weakref) { ... }

Note that, due to the nature of weak references, the pointer that QWeakPointer references can become \nullptr at any moment, so the value returned from this function can change from false to true from one call to the next.

See also: isNull()

Definition at line 551 of file qsharedpointer_impl.h.

References QWeakPointer< T >::isNull().

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◆ operator!=() [1/2]

template<class T >

template<class X >

bool QWeakPointer< T >::operator!= ( const QSharedPointer< X > & o ) const

inlinenoexcept

Definition at line 653 of file qsharedpointer_impl.h.

References o.

◆ operator!=() [2/2]

template<class T >

template<class X >

bool QWeakPointer< T >::operator!= ( const QWeakPointer< X > & o ) const

inlinenoexcept

Definition at line 645 of file qsharedpointer_impl.h.

References o.

◆ operator=() [1/5]

template<class T >

template< class T > QWeakPointer & QWeakPointer< T >::operator= ( const QSharedPointer< T > & other )

inline

Makes this object share other's pointer.

The current pointer reference is discarded but is not deleted.

If \tt T is a derived type of the template parameter of this class, QWeakPointer will perform an automatic cast. Otherwise, you will get a compiler error.

Definition at line 602 of file qsharedpointer_impl.h.

References o.

◆ operator=() [2/5]

template<class T >

template<class X , IfCompatible< X > = true>

QWeakPointer & QWeakPointer< T >::operator= ( const QSharedPointer< X > & o )

inline

Definition at line 628 of file qsharedpointer_impl.h.

References o.

◆ operator=() [3/5]

template<class T >

template< class T > QWeakPointer & QWeakPointer< T >::operator= ( const QWeakPointer< T > & other )

inlinenoexcept

Makes this object share other's pointer.

The current pointer reference is discarded but is not deleted.

If \tt T is a derived type of the template parameter of this class, QWeakPointer will perform an automatic cast. Otherwise, you will get a compiler error.

Definition at line 586 of file qsharedpointer_impl.h.

References copy(), other(), and QWeakPointer< T >::swap().

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◆ operator=() [4/5]

template<class T >

template<class X , IfCompatible< X > = true>

QWeakPointer & QWeakPointer< T >::operator= ( const QWeakPointer< X > & o )

inline

Definition at line 614 of file qsharedpointer_impl.h.

References o.

◆ operator=() [5/5]

template<class T >

template<class X , IfCompatible< X > = true>

QWeakPointer & QWeakPointer< T >::operator= ( QWeakPointer< X > && other )

inlinenoexcept

Definition at line 579 of file qsharedpointer_impl.h.

References other(), and QWeakPointer< T >::swap().

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◆ operator==() [1/2]

template<class T >

template<class X >

bool QWeakPointer< T >::operator== ( const QSharedPointer< X > & o ) const

inlinenoexcept

Definition at line 649 of file qsharedpointer_impl.h.

References o.

◆ operator==() [2/2]

template<class T >

template<class X >

bool QWeakPointer< T >::operator== ( const QWeakPointer< X > & o ) const

inlinenoexcept

Definition at line 641 of file qsharedpointer_impl.h.

References o.

◆ swap()

template<class T >

template< class T > void QWeakPointer< T >::swap ( QWeakPointer< T > & other )

inlinenoexcept

Since: 5.4

Swaps this weak pointer instance with other. This function is very fast and never fails.

Definition at line 593 of file qsharedpointer_impl.h.

References other(), and qt_ptr_swap().

Referenced by QWeakPointer< T >::operator=(), QWeakPointer< T >::operator=(), and QPointer< T >::swap().

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◆ toStrongRef()

template<class T >

template< class T > QSharedPointer< T > QWeakPointer< T >::toStrongRef ( ) const

inline

Promotes this weak reference to a strong one and returns a QSharedPointer object holding that reference.

When promoting to QSharedPointer, this function verifies if the object has been deleted already or not. If it hasn't, this function increases the reference count to the shared object, thus ensuring that it will not get deleted.

Since this function can fail to obtain a valid strong reference to the shared object, you should always verify if the conversion succeeded, by calling QSharedPointer::isNull() on the returned object.

For example, the following code promotes a QWeakPointer that was held to a strong reference and, if it succeeded, it prints the value of the integer that was held:

    QWeakPointer<int> weakref;
 
    // ...
 
    QSharedPointer<int> strong = weakref.toStrongRef();
    if (strong)
        qDebug() << "The value is:" << *strong;
    else
        qDebug() << "The value has already been deleted";

See also: QSharedPointer::QSharedPointer()

Definition at line 636 of file qsharedpointer_impl.h.

Referenced by QWeakPointer< T >::lock(), QQmlJSMetaMethod::returnType(), QDeferredWeakPointer< T >::toStrongRef(), QQmlJSMetaParameter::type(), and QQmlJSMetaProperty::type().

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Friends And Related Symbol Documentation

◆ QWeakPointer

template<class T >

template<class X >

template< class T > QWeakPointer< T >::QWeakPointer

friend

Creates a QWeakPointer that points to nothing.

Definition at line 675 of file qsharedpointer_impl.h.

Referenced by QWeakPointer< T >::clear().

◆ operator!=() [1/7]

template<class T >

template< class T > template< class X > bool operator!=	(	const QSharedPointer< T > &	ptr1,
		const QWeakPointer< X > &	ptr2
	)

If ptr2's template parameter is different from ptr1's, QSharedPointer will attempt to perform an automatic \tt static_cast to ensure that the pointers being compared are equal. If ptr2's template parameter is not a base or a derived type from ptr1's, you will get a compiler error.

◆ operator!= [2/7]

template<class T >

template<typename X >

bool operator!=	(	const QSharedPointer< X > &	p1,
		const QWeakPointer< T > &	p2
	)

friend

Definition at line 660 of file qsharedpointer_impl.h.

◆ operator!= [3/7]

template<class T >

template< class T > bool operator!=	(	const QWeakPointer< T > &	p,
		std::nullptr_t
	)

friend

Since: 5.8

Returns true if lhs refers to a valid (i.e. non-null) pointer.

See also: QWeakPointer::isNull()

Definition at line 667 of file qsharedpointer_impl.h.

◆ operator!=() [4/7]

template<class T >

template< class T > bool operator!=	(	const QWeakPointer< T > &	lhs,
		std::nullptr_t
	)

Since: 5.8

Returns true if lhs refers to a valid (i.e. non-null) pointer.

See also: QWeakPointer::isNull()

◆ operator!=() [5/7]

template<class T >

template< class T > template< class X > bool operator!=	(	const QWeakPointer< T > &	ptr1,
		const QSharedPointer< X > &	ptr2
	)

If ptr2's template parameter is different from ptr1's, QSharedPointer will attempt to perform an automatic \tt static_cast to ensure that the pointers being compared are equal. If ptr2's template parameter is not a base or a derived type from ptr1's, you will get a compiler error.

◆ operator!= [6/7]

template<class T >

template< class T > bool operator!=	(	std::nullptr_t	,
		const QWeakPointer< T > &	p
	)

friend

Since: 5.8

Returns true if rhs refers to a valid (i.e. non-null) pointer.

See also: QWeakPointer::isNull()

Definition at line 669 of file qsharedpointer_impl.h.

◆ operator!=() [7/7]

template<class T >

template< class T > bool operator!=	(	std::nullptr_t	,
		const QWeakPointer< T > &	rhs
	)

Since: 5.8

Returns true if rhs refers to a valid (i.e. non-null) pointer.

See also: QWeakPointer::isNull()

◆ operator==() [1/7]

template<class T >

template< class T > template< class X > bool operator==	(	const QSharedPointer< T > &	ptr1,
		const QWeakPointer< X > &	ptr2
	)

If ptr2's template parameter is different from ptr1's, QSharedPointer will attempt to perform an automatic \tt static_cast to ensure that the pointers being compared are equal. If ptr2's template parameter is not a base or a derived type from ptr1's, you will get a compiler error.

◆ operator== [2/7]

template<class T >

template<typename X >

bool operator==	(	const QSharedPointer< X > &	p1,
		const QWeakPointer< T > &	p2
	)

friend

Definition at line 657 of file qsharedpointer_impl.h.

◆ operator== [3/7]

template<class T >

template< class T > bool operator==	(	const QWeakPointer< T > &	p,
		std::nullptr_t
	)

friend

Since: 5.8

Returns true if lhs refers to \nullptr.

See also: QWeakPointer::isNull()

Definition at line 663 of file qsharedpointer_impl.h.

◆ operator==() [4/7]

template<class T >

template< class T > bool operator==	(	const QWeakPointer< T > &	lhs,
		std::nullptr_t
	)

Since: 5.8

Returns true if lhs refers to \nullptr.

See also: QWeakPointer::isNull()

◆ operator==() [5/7]

template<class T >

template< class T > template< class X > bool operator==	(	const QWeakPointer< T > &	ptr1,
		const QSharedPointer< X > &	ptr2
	)

If ptr2's template parameter is different from ptr1's, QSharedPointer will attempt to perform an automatic \tt static_cast to ensure that the pointers being compared are equal. If ptr2's template parameter is not a base or a derived type from ptr1's, you will get a compiler error.

◆ operator== [6/7]

template<class T >

template< class T > bool operator==	(	std::nullptr_t	,
		const QWeakPointer< T > &	p
	)

friend

Since: 5.8

Returns true if rhs refers to \nullptr.

See also: QWeakPointer::isNull()

Definition at line 665 of file qsharedpointer_impl.h.

◆ operator==() [7/7]

template<class T >

template< class T > bool operator==	(	std::nullptr_t	,
		const QWeakPointer< T > &	rhs
	)

Since: 5.8

Returns true if rhs refers to \nullptr.

See also: QWeakPointer::isNull()

◆ QPointer

template<class T >

template<class X >

friend class QPointer

friend

Definition at line 676 of file qsharedpointer_impl.h.

◆ QSharedPointer

template<class T >

template<class X >

friend class QSharedPointer

friend

Definition at line 674 of file qsharedpointer_impl.h.

◆ qSharedPointerCast()

template<class T >

template< class X > template< class T > QSharedPointer< X > qSharedPointerCast ( const QWeakPointer< T > & other )

The types \tt T and \tt X must belong to one hierarchy for the \tt static_cast to succeed.

The other object is converted first to a strong reference. If that conversion fails (because the object it's pointing to has already been deleted), this function returns a null QSharedPointer.

Note that \tt X must have the same cv-qualifiers (\tt const and \tt volatile) that \tt T has, or the code will fail to compile. Use qSharedPointerConstCast to cast away the constness.

See also: QWeakPointer::toStrongRef(), qSharedPointerDynamicCast(), qSharedPointerConstCast()

Definition at line 829 of file qsharedpointer_impl.h.

◆ qSharedPointerConstCast()

template<class T >

template< class X > template< class T > QSharedPointer< X > qSharedPointerConstCast ( const QWeakPointer< T > & src )

The types \tt T and \tt X must belong to one hierarchy for the \tt const_cast to succeed. The \tt const and \tt volatile differences between \tt T and \tt X are ignored.

The src object is converted first to a strong reference. If that conversion fails (because the object it's pointing to has already been deleted), this function returns a null QSharedPointer.

See also: QWeakPointer::toStrongRef(), qSharedPointerCast(), qSharedPointerDynamicCast()

Definition at line 855 of file qsharedpointer_impl.h.

◆ qSharedPointerDynamicCast()

template<class T >

template< class X > template< class T > QSharedPointer< X > qSharedPointerDynamicCast ( const QWeakPointer< T > & src )

If the \tt dynamic_cast fails, the object returned will be null.

The src object is converted first to a strong reference. If that conversion fails (because the object it's pointing to has already been deleted), this function also returns a null QSharedPointer.

Note that \tt X must have the same cv-qualifiers (\tt const and \tt volatile) that \tt T has, or the code will fail to compile. Use qSharedPointerConstCast to cast away the constness.

See also: QWeakPointer::toStrongRef(), qSharedPointerCast(), qSharedPointerConstCast()

Definition at line 843 of file qsharedpointer_impl.h.

◆ qSharedPointerObjectCast()

template<class T >

template< class X > template< class T > QSharedPointer< X > qSharedPointerObjectCast ( const QWeakPointer< T > & src )

Since: 4.6

Returns a shared pointer to the pointer held by src, using a \l qobject_cast() to type \tt X to obtain an internal pointer of the appropriate type. If the \tt qobject_cast fails, the object returned will be null.

The src object is converted first to a strong reference. If that conversion fails (because the object it's pointing to has already been deleted), this function also returns a null QSharedPointer.

Note that \tt X must have the same cv-qualifiers (\tt const and \tt volatile) that \tt T has, or the code will fail to compile. Use qSharedPointerConstCast to cast away the constness.

See also: QWeakPointer::toStrongRef(), qSharedPointerCast(), qSharedPointerConstCast()

Definition at line 875 of file qsharedpointer_impl.h.

◆ QtPrivate::EnableInternalData

template<class T >

friend struct QtPrivate::EnableInternalData

friend

Definition at line 673 of file qsharedpointer_impl.h.

◆ qWeakPointerCast()

template<class T >

template< class X > template< class T > QWeakPointer< X > qWeakPointerCast ( const QWeakPointer< T > & src )

The types \tt T and \tt X must belong to one hierarchy for the \tt static_cast to succeed.

Note that \tt X must have the same cv-qualifiers (\tt const and \tt volatile) that \tt T has, or the code will fail to compile. Use qSharedPointerConstCast to cast away the constness.

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

qtbase/src/corelib/tools/qsharedpointer_impl.h
qtbase/src/corelib/tools/qsharedpointer.cpp

Public Types

Public Member Functions

Friends

Related Symbols

Detailed Description

Member Typedef Documentation

◆ const_pointer

◆ const_reference

◆ difference_type

◆ element_type

◆ pointer

◆ reference

◆ value_type

Constructor & Destructor Documentation

◆ QWeakPointer() [1/7]

◆ ~QWeakPointer()

◆ QWeakPointer() [2/7]

◆ QWeakPointer() [3/7]

◆ QWeakPointer() [4/7]

◆ QWeakPointer() [5/7]

◆ QWeakPointer() [6/7]

◆ QWeakPointer() [7/7]

Member Function Documentation

◆ clear()

◆ isNull()

◆ lock()

◆ operator bool()

◆ operator!()

◆ operator!=() [1/2]

◆ operator!=() [2/2]

◆ operator=() [1/5]

◆ operator=() [2/5]

◆ operator=() [3/5]

◆ operator=() [4/5]

◆ operator=() [5/5]

◆ operator==() [1/2]

◆ operator==() [2/2]

◆ swap()

◆ toStrongRef()

Friends And Related Symbol Documentation

◆ QWeakPointer

◆ operator!=() [1/7]

◆ operator!= [2/7]

◆ operator!= [3/7]

◆ operator!=() [4/7]

◆ operator!=() [5/7]

◆ operator!= [6/7]

◆ operator!=() [7/7]

◆ operator==() [1/7]

◆ operator== [2/7]

◆ operator== [3/7]

◆ operator==() [4/7]

◆ operator==() [5/7]

◆ operator== [6/7]

◆ operator==() [7/7]

◆ QPointer

◆ QSharedPointer

◆ qSharedPointerCast()

◆ qSharedPointerConstCast()

◆ qSharedPointerDynamicCast()

◆ qSharedPointerObjectCast()

◆ QtPrivate::EnableInternalData

◆ qWeakPointerCast()