001/*
002 *  Licensed to the Apache Software Foundation (ASF) under one
003 *  or more contributor license agreements.  See the NOTICE file
004 *  distributed with this work for additional information
005 *  regarding copyright ownership.  The ASF licenses this file
006 *  to you under the Apache License, Version 2.0 (the
007 *  "License"); you may not use this file except in compliance
008 *  with the License.  You may obtain a copy of the License at
009 *
010 *    http://www.apache.org/licenses/LICENSE-2.0
011 *
012 *  Unless required by applicable law or agreed to in writing,
013 *  software distributed under the License is distributed on an
014 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 *  KIND, either express or implied.  See the License for the
016 *  specific language governing permissions and limitations
017 *  under the License.
018 *
019 */
020package org.apache.mina.util;
021
022import java.util.Collection;
023import java.util.IdentityHashMap;
024import java.util.Set;
025
026/**
027 * An {@link IdentityHashMap}-backed {@link Set}.
028 *
029 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
030 */
031public class IdentityHashSet<E> extends MapBackedSet<E> {
032
033    private static final long serialVersionUID = 6948202189467167147L;
034
035    public IdentityHashSet() {
036        super(new IdentityHashMap<E, Boolean>());
037    }
038
039    public IdentityHashSet(int expectedMaxSize) {
040        super(new IdentityHashMap<E, Boolean>(expectedMaxSize));
041    }
042
043    public IdentityHashSet(Collection<E> c) {
044        super(new IdentityHashMap<E, Boolean>(), c);
045    }
046}