#31 Add Clonable interface

[Jim Crafton]

Add a Clonable interface, make it look something like:

class Clonable : public Interface {
public:

Object* clone( bool deepCopy=false ) = 0;
};

This could be implemented as needed. Perhaps a
templated class impl:

template<typename CloneType>
class ClonableImpl {
public:
Object* clone( bool deepCopy=false ) {
return new CloneType( *this );
}
};

Perhaps a static method coule be added to the Object
class as a utilty method for testing for this:

static bool Object::isClonable( Object* obj );

implemented as
bool Object::isClonable( Object* obj )
{
return (NULL == dynamic_cast<Clonable*>(obj)) ? false
: true;
}

Usage:

Object* clonedInstance = NULL;

if ( Object::isClonable( srcInstance ) ) {

//perform some specific action

}

Clonable* cloneable = dynamic_cast<Clonable*>(srcInstance);

Object* clonedInstance = cloneable->clone();