Java Generics Capture List<?>

Question

I was looking at the Java Generics documentation and found this piece of code,

public class WildcardError {

void foo(List l) {
    //This give a co         


        

Answer 1

The compiler reports an error because there is no way -- in general -- that it can tell whether two expressions, (in this case l and l) refer to the same list.

Related, somewhat generalized, question:

• How does the JLS specify that wildcards cannot be formally used within methods?