How can I do this using Wildcards?

Question

Hi everyone,
I have a classed called LabeledDecimal which is a subclass of BigDecimal. Now, I have a class called Pair which is written using Wildcards.
This class has a copyFrom() method which looks like :
public void copyFrom(T p2)
     this.first = p2.first;
     this.second = p2.second;
}If I try to use this method like below:
Pair<BigDecimal> p1 = new Pair<BigDecimal>();
Pair<LabeledDecimal> p2 = new Pair<LabeledDecimal>(ld1, ld2);
p1.copyFrom(p2);Then I get the error:
The method copyFrom(Pair<BigDecimal>) in the type Pair<BigDecimal> is not applicable for the arguments (Pair<LabeledDecimal>)
How do I fix the copyFrom() method to get rid of this problem using wildcards?
Edited by: fantastic_ray on Mar 20, 2008 12:07 AM

Answer 1

Figured it out!
public void copyFrom(Pair<? extends T> p2) That will fix it.