mi::base::Interface_merger< MAJOR, MINOR > Class Template Reference

This mixin merges the implementation of one interface with a second interface. More...

Inherits MAJOR, and MINOR.

Public Types
typedef MAJOR	MAJOR_BASE
	Typedef for the MAJOR base class. More...
typedef MINOR	MINOR_BASE
	Typedef for the MINOR base class. More...

Public Member Functions
const IInterface *	get_interface (const Uuid &interface_id) const
	Reimplements mi::base::IInterface::get_interface(const Uuid&) const. More...
template<class T >
const T *	get_interface () const
	Reimplements mi::base::IInterface::get_interface() const. More...
IInterface *	get_interface (const Uuid &interface_id)
	Reimplements mi::base::IInterface::get_interface(const Uuid&). More...
template<class T >
T *	get_interface ()
	Reimplements mi::base::IInterface::get_interface(). More...
Uuid	get_iid () const
	Reimplements mi::base::IInterface::get_iid(). More...
mi::Uint32	retain () const
	Reimplements mi::base::IInterface::retain(). More...
mi::Uint32	release () const
	Reimplements mi::base::IInterface::release(). More...
const MAJOR *	cast_to_major () const
	Returns a pointer to the MAJOR base class. More...
MAJOR *	cast_to_major ()
	Returns a pointer to the MAJOR base class. More...

Static Public Member Functions
static bool	compare_iid (const Uuid &iid)
	Reimplements mi::base::IInterface::compare_iid(). More...

Detailed Description

template<typename MAJOR, typename MINOR>
class mi::base::Interface_merger< MAJOR, MINOR >

This mixin merges the implementation of one interface with a second interface.

Multiple inheritance from interfaces is not possible due to ambiguities. This mixin resolves the ambiguities by re-implementing the methods of mi::base::IInterface.

Note that this mixin class derives from an implementation and an interface, in contrast to mi::base::Interface_implement_2, which derives from two interfaces. Basically, Interface_merger<Interface_implement<I1>,I2> is equivalent to Interface_implement<I1,I2>. The benefit of this mixin class is that you are not bound to use Interface_implement, any valid implementation of an interface will do.

The template parameters representing the base classes are called MAJOR and MINOR. Note that the derivation is not symmetric:

• MAJOR has to be an implementation of an interface, MINOR has to be just an interface
• retain() and release() are redirected to the MAJOR base class
• compared_iid() and get_interface() are redirected to the MAJOR base class first, the MINOR base class is only queried on failure. For example, get_interface<mi::base::IInterface>() will always return the MAJOR base class.
• get_iid() is redirected to the MAJOR base class.

Note that some versions of Microsoft Visual C++ are known to produce the bogus warning

disable C4505: <class::method>: unreferenced local function has been removed 

in conjunction with this class. This warning can be disabled with

#include <mi/base/config.h>
#ifdef MI_COMPILER_MSC

#pragma warning( disable : 4505 )

#endif

Note that the pragma affects the entire translation unit. Therefore, the warning is not disabled by default.

Template Parameters

MAJOR	the implementation base class
MINOR	the interface base class

Member Typedef Documentation

template<typename MAJOR , typename MINOR >

typedef MAJOR mi::base::Interface_merger< MAJOR, MINOR >::MAJOR_BASE

Typedef for the MAJOR base class.

template<typename MAJOR , typename MINOR >

typedef MINOR mi::base::Interface_merger< MAJOR, MINOR >::MINOR_BASE

Typedef for the MINOR base class.

Member Function Documentation

template<typename MAJOR , typename MINOR >

const MAJOR* mi::base::Interface_merger< MAJOR, MINOR >::cast_to_major ( ) const

inline

Returns a pointer to the MAJOR base class.

Note that mi::base::IInterface is an ambiguous base class. Often you just need a pointer to mi::base::IInterface but do not really care to which base class it actually points to. This method is intended to be used in these cases. It returns the pointer to the MAJOR base class, which can then be statically casted to mi::base::IInterface (unless Interface_merger is nested).

Note

The name cast_to_major() of this method emphasizes that it behaves similar to a static cast, in particular, it does not increase the reference count.

template<typename MAJOR , typename MINOR >

MAJOR* mi::base::Interface_merger< MAJOR, MINOR >::cast_to_major ( )

inline

Returns a pointer to the MAJOR base class.

Note that mi::base::IInterface is an ambiguous base class. Often you just need a pointer to mi::base::IInterface but do not really care to which base class it actually points to. This method is intended to be used in these cases. It returns the pointer to the MAJOR base class, which can then be statically casted to mi::base::IInterface (unless Interface_merger is nested).

Note

The name cast_to_major() of this method emphasizes that it behaves similar to a static cast, in particular, it does not increase the reference count.

template<typename MAJOR , typename MINOR >

static bool mi::base::Interface_merger< MAJOR, MINOR >::compare_iid ( const Uuid &  iid)

inlinestatic

Reimplements mi::base::IInterface::compare_iid().

Forwards the call to the MAJOR base class, and then, in case of failure, to the MINOR base class.

template<typename MAJOR , typename MINOR >

Uuid mi::base::Interface_merger< MAJOR, MINOR >::get_iid ( ) const

inline

Reimplements mi::base::IInterface::get_iid().

Forwards the call to the MAJOR base class.

template<typename MAJOR , typename MINOR >

template<class T >

const T* mi::base::Interface_merger< MAJOR, MINOR >::get_interface ( ) const

inline

Reimplements mi::base::IInterface::get_interface() const.

The implementation is identical, but needed for visibility reasons.

template<typename MAJOR , typename MINOR >

template<class T >

T* mi::base::Interface_merger< MAJOR, MINOR >::get_interface ( )

inline

Reimplements mi::base::IInterface::get_interface().

The implementation is identical, but needed for visibility reasons.

template<typename MAJOR , typename MINOR >

mi::Uint32 mi::base::Interface_merger< MAJOR, MINOR >::release ( ) const

inline

Reimplements mi::base::IInterface::release().

Forwards the call to the MAJOR base class.

template<typename MAJOR , typename MINOR >

mi::Uint32 mi::base::Interface_merger< MAJOR, MINOR >::retain ( ) const

inline

Reimplements mi::base::IInterface::retain().

Forwards the call to the MAJOR base class.