Thread: I'm misunderstanding dynamic binding

I'm not being able to properly access dynamic binding from inside one of my derived classes member function definition.

CContainer is a derived of CItem. The former adds a ContentsWeight() member.

CContainer also adds a add() member. And this is where I'm having troubles:

Code:

CContainer& CContainer::add(CItem* obj) {

/* ... */
int objW = obj->weight() + obj->ContentsWeight();
/* ... */
}

I can understand why I can't do this and why I get an error saying that ContentsWeight is not a member of CItem. After all, obj could be some other type of derived object, or the base itself. Only CContainer declares ContentsWeight.

But I'm not sure how to best solve this. I do need to access ContentsWeight on that code.