/*

 * Copyright (C) 2000 Lars Knoll (knoll@kde.org)

 *           (C) 2000 Antti Koivisto (koivisto@kde.org)

 *           (C) 2000 Dirk Mueller (mueller@kde.org)

 * Copyright (C) 2003, 2005, 2008 Apple Inc. All rights reserved.

 *

 * This library 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; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library 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

 * Library General Public License for more details.

 *

 * You should have received a copy of the GNU Library General Public License

 * along with this library; see the file COPYING.LIB.  If not, write to

 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 *

 */

#ifndef DataRef_h

#define DataRef_h

#include <wtf/RefPtr.h>

namespace WebCore {

template <typename T> class DataRef {

public:

    const T* get() const { return m_data.get(); }

    const T& operator*() const { return *get(); }

    const T* operator->() const { return get(); }

    T* access()

    {

        if (!m_data->hasOneRef())

            m_data = m_data->copy();

        return m_data.get();

    }

    void init()

    {

        ASSERT(!m_data);

        m_data = T::create();

    }

    bool operator==(const DataRef<T>& o) const

    {

        ASSERT(m_data);

        ASSERT(o.m_data);

        return m_data == o.m_data || *m_data == *o.m_data;

    }

    bool operator!=(const DataRef<T>& o) const

    {

        ASSERT(m_data);

        ASSERT(o.m_data);

        return m_data != o.m_data && *m_data != *o.m_data;

    }

private:

    RefPtr<T> m_data;

};

} // namespace WebCore

#endif // DataRef_h