What is the problem with this Java code dealing with Generics?
- by devoured elysium
interface Addable<E> {
public E add(E x);
public E sub(E y);
public E zero();
}
class SumSet<E extends Addable> implements Set<E> {
private E element;
public SumSet(E element) {
this.element = element;
}
public E getSum() {
return element.add(element.zero());
}
}
It seems that element.add() doesn't return an E extends Addable but rather an Object. Why is that? Has it anything to do with Java not knowing at run-time what the object types really are, so it just assumes them to be Objects(thus requiring a cast)?
Thanks
