OnJava8-Examples/generics/SelfBoundingAndCovariantArguments.java

// generics/SelfBoundingAndCovariantArguments.java
// (c)2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://mindviewinc.com/Books/OnJava/ for more book information.

interface SelfBoundSetter<T extends SelfBoundSetter<T>> {
  void set(T arg);
}

interface Setter extends SelfBoundSetter<Setter> {}

public class SelfBoundingAndCovariantArguments {
  void testA(Setter s1, Setter s2, SelfBoundSetter sbs) {
    s1.set(s2);
    // s1.set(sbs); // Error:
    // set(Setter) in SelfBoundSetter<Setter>
    // cannot be applied to (SelfBoundSetter)
  }
}