/*
 * Copyright (c) 2005 Brian Goetz and Tim Peierls
 * Released under the Creative Commons Attribution License
 *   (http://creativecommons.org/licenses/by/2.5)
 * Official home: http://www.jcip.net
 *
 * Any republication or derived work distributed in source code form
 * must include this copyright and license notice.
 */

package com.mongodb.annotations;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

The class to which this annotation is applied is immutable.  This means that its state cannot be seen to change by callers, which
implies that

    
 all public fields are final, 
    
 all public final reference fields refer to other immutable objects, and 
    
 constructors and methods do not publish references to any internal state which is potentially mutable by the
         implementation. 

Immutable objects may still have internal mutable state for purposes of performance optimization; some state
variables may be lazily computed, so long as they are computed from immutable state and that callers cannot tell the difference. 
Immutable objects are inherently thread-safe; they may be passed between threads or published without synchronization.
/**
 * <p>The class to which this annotation is applied is immutable.  This means that its state cannot be seen to change by callers, which
 * implies that</p>
 * <ul>
 *     <li> all public fields are final, </li>
 *     <li> all public final reference fields refer to other immutable objects, and </li>
 *     <li> constructors and methods do not publish references to any internal state which is potentially mutable by the
 *          implementation. </li>
 * </ul>
 * <p>Immutable objects may still have internal mutable state for purposes of performance optimization; some state
 * variables may be lazily computed, so long as they are computed from immutable state and that callers cannot tell the difference. </p>
 *
 * <p>Immutable objects are inherently thread-safe; they may be passed between threads or published without synchronization.</p>
 */
@Documented
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface Immutable {
}