Array covariance unsoundness.java

class B { }

class Main {
  public static void main(String[] args) {
    B strMain = Main.<String>cast("this is not a b");
    System.out.println(strMain.toString());
  }

  public static <A extends Object> B cast(A a) {
    B[] ary = new B[1];
    put(ary, a);
    return ary[0];
  }

  public static void put(Object[] ary, Object o) {
    ary[0] = o;
  }
}