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/*************************************************************************
/* ObjectIdentityWrapper.java -- Wrapper class used to override equals()
/* and hashCode() to be as discriminating
/* as possible
/*
/* Copyright (c) 1998 by Geoffrey C. Berry (gcb@cs.duke.edu)
/*
/* This program is free software; you can redistribute it and/or modify
/* it under the terms of the GNU Library General Public License as published
/* by the Free Software Foundation, version 2. (see COPYING.LIB)
/*
/* This program is distributed in the hope that it will be useful, but
/* WITHOUT ANY WARRANTY; without even the implied warranty of
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
/* GNU General Public License for more details.
/*
/* You should have received a copy of the GNU General Public License
/* along with this program; if not, write to the Free Software Foundation
/* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307 USA
/*************************************************************************/
package gnu.java.io;
/**
This class is a thin wrapper around <code>Object</code> that makes
the methods <code>hashCode()</code> and <code>equals(Object)</code>
as discriminating as possible.
*/
public class ObjectIdentityWrapper
{
/**
Constructs a <code>ObjectIdentityWrapper</code> that is wrapped
around o.
*/
public ObjectIdentityWrapper( Object o )
{
object = o;
}
/**
Uses <code>System.identityHashCode(Object)</code> to compute a
hash code for the object wrapped by this
<code>ObjectIdentityWrapper</code>.
@see java.lang.System#identityHashCode(java.lang.Object)
@see java.util.Hashtable
@see java.lang.Object#hashCode()
*/
public int hashCode()
{
return System.identityHashCode( object );
}
/**
Uses the <code>==</code> operator to test for equality between
the object wrapped by this <code>ObjectIdentityWrapper</code> and
the object wrapped by the <code>ObjectIdentityWrapper</code> o.
Returns false if o is not a <code>ObjectIdentityWrapper</code>.
@see java.util.Hashtable
@see java.lang.Object#equals()
*/
public boolean equals( Object o )
{
if( o instanceof ObjectIdentityWrapper )
return object == ((ObjectIdentityWrapper)o).object;
else
return false;
}
public String toString()
{
return "ObjectIdentityWrapper< " + object + ", " + hashCode() + " >";
}
/**
The <code>Object</code> wrapped by this
<code>ObjectIdentityWrapper</code>.
*/
public Object object;
}
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