/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is XPCOM Array implementation.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corp.
 * Portions created by the Initial Developer are Copyright (C) 2002
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Alec Flett <alecf@netscape.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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 * decision by deleting the provisions above and replace them with the notice
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 * the provisions above, a recipient may use your version of this file under
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 *
 * ***** END LICENSE BLOCK ***** */

#ifndef nsArrayUtils_h__
#define nsArrayUtils_h__

#include "nsCOMPtr.h"
#include "nsIArray.h"

// helper class for do_QueryElementAt
class NS_COM_GLUE nsQueryArrayElementAt : public nsCOMPtr_helper
  {
    public:
      nsQueryArrayElementAt(nsIArray* aArray, PRUint32 aIndex,
                            nsresult* aErrorPtr)
          : mArray(aArray),
            mIndex(aIndex),
            mErrorPtr(aErrorPtr)
        {
          // nothing else to do here
        }

      virtual nsresult NS_FASTCALL operator()(const nsIID& aIID, void**) const;

    private:
      nsIArray*  mArray;
      PRUint32   mIndex;
      nsresult*  mErrorPtr;
  };

inline
const nsQueryArrayElementAt
do_QueryElementAt(nsIArray* aArray, PRUint32 aIndex, nsresult* aErrorPtr = 0)
  {
    return nsQueryArrayElementAt(aArray, aIndex, aErrorPtr);
  }

#endif // nsArrayUtils_h__