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Java lang extensions for java6+, a supplement to , replacement of a Guava, commons-lang. Core utilities, Collection utilities, IO utilities, Cache, Configuration library ...

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package com.jn.langx.util.collection;


import java.util.*;

/**
 * An {@link IdentityHashMap}-backed {@link Set}.
 *
 * @author The Apache Directory Project ([email protected])
 * @version $Rev: 555855 $, $Date: 2007-07-13 12:19:00 +0900 (Fri, 13 Jul 2007) $
 */
public class IdentityHashSet extends AbstractSet {
    private final Map delegate = new IdentityHashMap();

    public IdentityHashSet() {
    }

    public IdentityHashSet(Collection c) {
        addAll(c);
    }

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

    @Override
    public boolean contains(Object o) {
        //noinspection SuspiciousMethodCalls
        return delegate.containsKey(o);
    }

    @Override
    public Iterator iterator() {
        return delegate.keySet().iterator();
    }

    @Override
    public boolean add(E arg0) {
        return delegate.put(arg0, Boolean.TRUE) == null;
    }

    @Override
    public boolean remove(Object o) {
        //noinspection SuspiciousMethodCalls
        return delegate.remove(o) != null;
    }

    @Override
    public void clear() {
        delegate.clear();
    }
}