FUnknown Class Reference

The basic interface of all interfaces. More...

#include <funknown.h>

Inheritance diagram for FUnknown:

Public Member Functions
virtual tresult	queryInterface (const TUID _iid, void **obj)=0
	Query for a pointer to the specified interface. More...
virtual uint32	addRef ()=0
	Adds a reference and returns the new reference count. More...
virtual uint32	release ()=0
	Releases a reference and returns the new reference count. More...

Static Public Attributes
static const FUID	iid

Detailed Description

The basic interface of all interfaces.

• The FUnknown::queryInterface method is used to retrieve pointers to other interfaces of the object.
• FUnknown::addRef and FUnknown::release manage the lifetime of the object. If no more references exist, the object is destroyed in memory.

Interfaces are identified by 16 byte Globally Unique Identifiers. The SDK provides a class called FUID for this purpose.

howtoClass

Member Function Documentation

queryInterface()

virtual tresult queryInterface ( const TUID  _iid, void **  obj  )

pure virtual

Query for a pointer to the specified interface.

Returns kResultOk on success or kNoInterface if the object does not implement the interface. The object has to call addRef when returning an interface.

Parameters

_iid	: (in) 16 Byte interface identifier (-> FUID)
obj	: (out) On return, *obj points to the requested interface

addRef()

virtual uint32 addRef ( )

pure virtual

Adds a reference and returns the new reference count.

Remarks:

The initial reference count after creating an object is 1.

release()

virtual uint32 release ( )

pure virtual

Releases a reference and returns the new reference count.

If the reference count reaches zero, the object will be destroyed in memory.

Member Data Documentation

iid

const FUID iid

static