c++ abstract base class postfix operator

c++ abstract base class postfix operator

I have a question about implementing a shared iterator interface.
As common practice for postix operator the function might look like this:
IteratorClass operator ++(int) {
IteratorClass temp = *this;
//increment stuff
return temp
}
And most of the time this is fine. In my case I am trying to implement 3
iterators for one class. Each iterator will load a local collection class
with data but each derived iterator would load it in a different way.
Because the collection class would be the same and all of the code for the
operators( postfix/prefix ++/--, *) would be the same I thought a nice way
to implement this would be inheritance:
struct iterator {
protected:
Collection collection;
public:
operator++(int);
operator++;
operator--(int);
operator--;
virtual load() = 0;
}
struct iterator1 : public iterator {
virtual load() { custom load function }
}
struct iterator2 : public iterator {
virtual load() { custom load function }
}
The problem are the postfix operators... They are trying to create an
object of an abstract type and then returning it. Any suggestions for
workarounds or structure changes?