Glib::WeakRef< T_CppObject > Class Template Reference

WeakRef<> is a weak reference smartpointer. More...

#include <glibmm/weakref.h>

Public Member Functions
	WeakRef () noexcept
	Default constructor. More...
	WeakRef (const WeakRef & src) noexcept
	Copy constructor. More...
	WeakRef (WeakRef && src) noexcept
	Move constructor. More...
template<typename T_CastFrom >
	WeakRef (const WeakRef< T_CastFrom > & src) noexcept
	Copy constructor from different, but castable type. More...
template<typename T_CastFrom >
	WeakRef (WeakRef< T_CastFrom > && src) noexcept
	Move constructor from different, but castable type. More...
template<typename T_CastFrom >
	WeakRef (const RefPtr< T_CastFrom > & src) noexcept
	Constructor from a RefPtr of the same or a castable type. More...
	~WeakRef () noexcept
	Destructor. More...
void	swap (WeakRef & other) noexcept
	Swap the contents of two WeakRef<>. More...
WeakRef &	operator= (const WeakRef & src) noexcept
	Copy assignment operator. More...
WeakRef &	operator= (WeakRef && src) noexcept
	Move assignment operator. More...
template<typename T_CastFrom >
WeakRef &	operator= (const WeakRef< T_CastFrom > & src) noexcept
	Copy assignment from different, but castable type. More...
template<typename T_CastFrom >
WeakRef &	operator= (WeakRef< T_CastFrom > && src) noexcept
	Move assignment from different, but castable type. More...
template<typename T_CastFrom >
WeakRef &	operator= (const RefPtr< T_CastFrom > & src) noexcept
	Assignment from a RefPtr of the same or a castable type. More...
	operator bool () const noexcept
	Test whether the WeakRef<> points to any underlying instance. More...
RefPtr< T_CppObject >	get () const noexcept
	Create a strong reference to the underlying object. More...
void	reset () noexcept
	Make this WeakRef empty. More...

Static Public Member Functions
template<typename T_CastFrom >
static WeakRef	cast_dynamic (const WeakRef< T_CastFrom > & src) noexcept
	Dynamic cast to derived class. More...
template<typename T_CastFrom >
static WeakRef	cast_static (const WeakRef< T_CastFrom > & src) noexcept
	Static cast to derived class. More...
template<typename T_CastFrom >
static WeakRef	cast_const (const WeakRef< T_CastFrom > & src) noexcept
	Cast to non-const. More...

Related Functions
(Note that these are not member functions.)
template<class T_CppObject >
void	swap (WeakRef< T_CppObject > & lhs, WeakRef< T_CppObject > & rhs) noexcept
	Swap the contents of two WeakRef<>. More...

Detailed Description

template<typename T_CppObject>
class Glib::WeakRef< T_CppObject >

WeakRef<> is a weak reference smartpointer.

WeakRef can store a pointer to any class that is derived from Glib::ObjectBase, and whose reference() method is noexcept. In glibmm and gtkmm, that is anything derived from Glib::ObjectBase.

Unlike a RefPtr, a WeakRef does not contribute to the reference counting of the underlying object.

Since glibmm 2.46:

Constructor & Destructor Documentation

WeakRef() [1/6]

template <typename T_CppObject >

Glib::WeakRef< T_CppObject >::WeakRef ( )

inlinenoexcept

Default constructor.

Create an empty weak reference.

WeakRef() [2/6]

template <typename T_CppObject >

Glib::WeakRef< T_CppObject >::WeakRef ( const WeakRef< T_CppObject > &  src )

inlinenoexcept

Copy constructor.

WeakRef() [3/6]

template <typename T_CppObject >

Glib::WeakRef< T_CppObject >::WeakRef ( WeakRef< T_CppObject > &&  src )

inlinenoexcept

Move constructor.

WeakRef() [4/6]

template <typename T_CppObject >

template <typename T_CastFrom >

Glib::WeakRef< T_CppObject >::WeakRef ( const WeakRef< T_CastFrom > &  src )

inlinenoexcept

Copy constructor from different, but castable type.

WeakRef() [5/6]

template <typename T_CppObject >

template <typename T_CastFrom >

Glib::WeakRef< T_CppObject >::WeakRef ( WeakRef< T_CastFrom > &&  src )

inlinenoexcept

Move constructor from different, but castable type.

WeakRef() [6/6]

template <typename T_CppObject >

template <typename T_CastFrom >

Glib::WeakRef< T_CppObject >::WeakRef ( const RefPtr< T_CastFrom > &  src )

inlinenoexcept

Constructor from a RefPtr of the same or a castable type.

Create a weak reference from a RefPtr of the same or a castable type. If the RefPtr references nothing, an empty weak reference will be constructed.

~WeakRef()

template <typename T_CppObject >

Glib::WeakRef< T_CppObject >::~WeakRef ( )

inlinenoexcept

Destructor.

Member Function Documentation

cast_const()

template <typename T_CppObject >

template <typename T_CastFrom >

static WeakRef Glib::WeakRef< T_CppObject >::cast_const ( const WeakRef< T_CastFrom > &  src )

inlinestaticnoexcept

Cast to non-const.

The WeakRef can't be cast with the usual notation so instead you can use

ptr_nonconst = Glib::WeakRef<NonConstType>::cast_const(ptr_const);

cast_dynamic()

template <typename T_CppObject >

template <typename T_CastFrom >

static WeakRef Glib::WeakRef< T_CppObject >::cast_dynamic ( const WeakRef< T_CastFrom > &  src )

inlinestaticnoexcept

Dynamic cast to derived class.

The WeakRef can't be cast with the usual notation so instead you can use

ptr_derived = Glib::WeakRef<Derived>::cast_dynamic(ptr_base);

cast_static()

template <typename T_CppObject >

template <typename T_CastFrom >

static WeakRef Glib::WeakRef< T_CppObject >::cast_static ( const WeakRef< T_CastFrom > &  src )

inlinestaticnoexcept

Static cast to derived class.

The WeakRef can't be cast with the usual notation so instead you can use

ptr_derived = Glib::WeakRef<Derived>::cast_static(ptr_base);

get()

template <typename T_CppObject >

RefPtr< T_CppObject > Glib::WeakRef< T_CppObject >::get ( ) const

inlinenoexcept

Create a strong reference to the underlying object.

This is a thread-safe way to acquire a strong reference to the underlying object. If the WeakRef is empty, the returned RefPtr will reference nothing.

operator bool()

template <typename T_CppObject >

Glib::WeakRef< T_CppObject >::operator bool ( ) const

inlineexplicitnoexcept

Test whether the WeakRef<> points to any underlying instance.

Mimics usage of ordinary pointers:

if (ptr)
  do_something();

In a multi-threaded program a true return value can become obsolete at any time, even before the caller has a chance to test it, because the underlying instance may lose its last reference in another thread. Use get() if this is not acceptable.

operator=() [1/5]

template <typename T_CppObject >

template <typename T_CastFrom >

WeakRef & Glib::WeakRef< T_CppObject >::operator= ( const RefPtr< T_CastFrom > &  src )

inlinenoexcept

Assignment from a RefPtr of the same or a castable type.

operator=() [2/5]

template <typename T_CppObject >

WeakRef & Glib::WeakRef< T_CppObject >::operator= ( const WeakRef< T_CppObject > &  src )

inlinenoexcept

Copy assignment operator.

operator=() [3/5]

template <typename T_CppObject >

template <typename T_CastFrom >

WeakRef & Glib::WeakRef< T_CppObject >::operator= ( const WeakRef< T_CastFrom > &  src )

inlinenoexcept

Copy assignment from different, but castable type.

operator=() [4/5]

template <typename T_CppObject >

WeakRef & Glib::WeakRef< T_CppObject >::operator= ( WeakRef< T_CppObject > &&  src )

inlinenoexcept

Move assignment operator.

operator=() [5/5]

template <typename T_CppObject >

template <typename T_CastFrom >

WeakRef & Glib::WeakRef< T_CppObject >::operator= ( WeakRef< T_CastFrom > &&  src )

inlinenoexcept

Move assignment from different, but castable type.

reset()

template <typename T_CppObject >

void Glib::WeakRef< T_CppObject >::reset ( )

inlinenoexcept

Make this WeakRef empty.

swap()

template <typename T_CppObject >

void Glib::WeakRef< T_CppObject >::swap ( WeakRef< T_CppObject > &  other )

inlinenoexcept

Swap the contents of two WeakRef<>.

Friends And Related Function Documentation

swap()

template <class T_CppObject >

void swap ( WeakRef< T_CppObject > &  lhs, WeakRef< T_CppObject > &  rhs  )

related

Swap the contents of two WeakRef<>.