What is the best way to create related types at runtime?
- by SniperSmiley
How do I determine the type of a class that is related to another class at runtime?
I have figured out a solution, the only problem is that I ended up having to use a define that has to be used in all of the derived classes.
Is there a simpler way to do this that doesn't need the define or a copy paste?
Things to note: both the class and the related class will always have their respective base class, the different classes can share a related class, and as in the example I would like the control class to own the view.
#include <iostream>
#include <string>
class model;
class view {
public:
view( model *m ) {}
virtual std::string display() {
return "view";
}
};
#define RELATED_CLASS(RELATED)\
typedef RELATED relatedType;\
virtual relatedType*createRelated(){\
return new relatedType(this);}
class model {
public:
RELATED_CLASS(view)
model() {}
};
class otherView : public view {
public:
otherView( model *m ) : view(m) {}
std::string display() {
return "otherView";
}
};
class otherModel : public model {
public:
RELATED_CLASS(otherView)
otherModel() {}
};
class control {
public:
control( model *m ) : m_(m),
v_( m->createRelated() ) {}
~control() { delete v_; }
std::string display() {
return v_->display();
}
model *m_;
view *v_;
};
int main( void ) {
model m;
otherModel om;
model *pm = &om;
control c1( &m );
control c2( &om );
control c3( pm );
std::cout << c1.display() << std::endl;
std::cout << c2.display() << std::endl;
std::cout << c3.display() << std::endl;
}
