/*
 * Javolution - Java(TM) Solution for Real-Time and Embedded Systems
 * Copyright (C) 2005 - Javolution (http://javolution.org/)
 * All rights reserved.
 * 
 * Permission to use, copy, modify, and distribute this software is
 * freely granted, provided that this notice is preserved.
 */
package javolution37.javolution.lang;

/**
 * 
 This interface identifies classes whose instances are not subject or 
 *     susceptible to change or variation after creation. Once a class is 
 *     declared immutable, any subclass must ensure immutability as well.
 *     
 * 
 {@link Immutable} objects can safely be used in a multi-threaded 
 *     environment and do not require defensive copying.
 *     For example:[code]
 *     class Polygon implements Immutable {
 *          private List _vertices;
 *          public Polygon(List vertices) {
 *              _vertices = (vertices instanceof Immutable) ?
 *                   vertices : // Safe, the vertices cannot be modified by the client.
 *                   new FastTable(vertices); // Defensive copying required.
 *          }
 *     }[/code]
 * @see 
 *      Wikipedia: Immutable Object    
 * 
 * @author  Jean-Marie Dautelle
 * @version 3.7, February 6, 2006
 */
public interface Immutable {

   // Tagging interface, no method.
    
}