Any way to make a generic List where I can add a type AND a subtype?
Posted
by
user383178
on Stack Overflow
See other posts from Stack Overflow
or by user383178
Published on 2011-01-05T23:35:08Z
Indexed on
2011/01/05
23:54 UTC
Read the original article
Hit count: 145
I understand why I cannot do the following:
private class Parent {
};
private class Child extends Parent {
};
private class GrandChild extends Child {
};
public void wontCompile(List<? extends Parent> genericList, Child itemToAdd) {
genericList.add(itemToAdd);
}
My question is there ANY practical way to have a typesafe List where you can call add(E) where E is known to be only a Parent or a Child?
I vaguely remember some use of the "|" operator as used for wildcard bounds, but I cannot find it in the spec...
Thanks!
© Stack Overflow or respective owner
