/*
 * Copyright (C) 2007 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.glassfish.jersey.internal.guava;

import java.util.Set;

A set which forwards all its method calls to another set. Subclasses should
override one or more methods to modify the behavior of the backing set as
desired per the decorator pattern.

Warning: The methods of ForwardingSet forward indiscriminately to the methods of the delegate. For example, overriding ForwardingCollection.add alone will not change the behavior of ForwardingCollection.addAll, which can lead to unexpected behavior. In this case, you should override addAll as well, either providing your own implementation, or delegating to the provided standardAddAll method. 

The standard methods are not guaranteed to be thread-safe, even when all of the methods that they depend on are thread-safe. 
Author:
Kevin Bourrillion, Louis Wasserman
Since:
2.0 (imported from Google Collections Library)/**
 * A set which forwards all its method calls to another set. Subclasses should
 * override one or more methods to modify the behavior of the backing set as
 * desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 * <p>
 * <p><b>Warning:</b> The methods of {@code ForwardingSet} forward
 * <b>indiscriminately</b> to the methods of the delegate. For example,
 * overriding {@link #add} alone <b>will not</b> change the behavior of {@link
 * #addAll}, which can lead to unexpected behavior. In this case, you should
 * override {@code addAll} as well, either providing your own implementation, or
 * delegating to the provided {@code standardAddAll} method.
 * <p>
 * <p>The {@code standard} methods are not guaranteed to be thread-safe, even
 * when all of the methods that they depend on are thread-safe.
 *
 * @author Kevin Bourrillion
 * @author Louis Wasserman
 * @since 2.0 (imported from Google Collections Library)
 */
public abstract class ForwardingSet<E> extends ForwardingCollection<E>
        implements Set<E> {
    // TODO(user): identify places where thread safety is actually lost

    
Constructor for use by subclasses.
/**
     * Constructor for use by subclasses.
     */
    ForwardingSet() {
    }

    @Override
    protected abstract Set<E> delegate();

    @Override
    public boolean equals(Object object) {
        return object == this || delegate().equals(object);
    }

    @Override
    public int hashCode() {
        return delegate().hashCode();
    }

}