OnJava8-Examples/generics/Diamond.java

//: generics/Diamond.java
// <20>2015 MindView LLC: see Copyright.txt

public class Diamond<T> {
  private T a;
  public Diamond(T a) { this.a = a; }
  public void set(T a) { this.a = a; }
  public T get() { return a; }
  public static void main(String[] args) {
    Diamond<Automobile> h3 =
      new Diamond<>(new Automobile());
    Automobile a = h3.get(); // No cast needed
    // h3.set("Not an Automobile"); // Error
    // h3.set(1); // Error
  }
} ///:~