Limitations of Generics

• Cannot replace type variables with primitive types
  
• Cannot construct new objects of generic type
  a.add(new E()); // Error--would erase to new Object()
• Workaround: Use class literals
  

  public static <E> void fillWithDefaults(ArrayList<E>,
     Class<? extends E> cl, int count)
     throws InstantiationException, IllegalAccessException
  {
     for (int i = 0; i < count; i++)
        a.add(cl.newInstance());
  }

• Call as fillWithDefaults(a, Rectangle.class, count)