/*

 * Copyright (c) 2006 INRIA

 * All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation;

 *

 * 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

 *

 * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

 */

#ifndef STREAM_TRACER_H

#define STREAM_TRACER_H

#include <ostream>

namespace ns3 {

/**

 * \brief log arbitrary data to std::ostreams

 * 

 * Whenever operator << is invoked on this class,

 * it is forwarded to the stored std::ostream output

 * stream (if there is one).

 */

class StreamTracer {

public:

    StreamTracer ()

        : m_os (0) {}

    template <typename T>

    StreamTracer &operator << (T const&v) {

        if (m_os != 0) {

            (*m_os) << v;

        }

        return *this;

    }

    template <typename T>

    StreamTracer &operator << (T &v) {

        if (m_os != 0) {

            (*m_os) << v;

        }

        return *this;

    }

    StreamTracer &operator << (std::ostream &(*v) (std::ostream &)) {

        if (m_os != 0) {

            (*m_os) << v;

        }

        return *this;

    }

    /**

     * \param os the output stream to store

     */

    void SetStream (std::ostream * os) {

        m_os = os;

    }

private:

    std::ostream *m_os;

};

}; // namespace ns3

#endif /* TRACER_STREAM_H */