Dereferencer.hpp

Go to the documentation of this file.

/* 
 * Dereferencer.hpp 
 *
 * This file is part of the Chemical Data Processing Toolkit
 *
 * Copyright (C) 2003 Thomas Seidel <thomas.seidel@univie.ac.at>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; see the file COPYING. If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */
 
#ifndef CDPL_UTIL_DEREFERENCER_HPP
#define CDPL_UTIL_DEREFERENCER_HPP
 
#include "CDPL/Base/Exceptions.hpp"
 
 
namespace CDPL
{
 
    namespace Util
    {
 
        template <typename ArgType, typename ResType>
        struct Dereferencer
        {
 
          public:
            typedef ResType result_type;
 
            ResType operator()(const ArgType& ptr) const;
        };
 
        template <typename ArgType, typename ResType>
        struct NullCheckDereferencer
        {
 
          public:
            typedef ResType result_type;
 
            ResType operator()(const ArgType& ptr) const;
        };
    } // namespace Util
} // namespace CDPL
 
 
// Implementation
 
template <typename ArgType, typename ResType>
ResType CDPL::Util::Dereferencer<ArgType, ResType>::operator()(const ArgType& ptr) const
{
    return *ptr;
}
 
template <typename ArgType, typename ResType>
ResType CDPL::Util::NullCheckDereferencer<ArgType, ResType>::operator()(const ArgType& ptr) const
{
    if (!ptr)
        throw Base::NullPointerException("NullCheckDereferencer: attempt to dereference null pointer");
 
    return *ptr;
}
 
#endif // CDPL_UTIL_DEREFERENCER_HPP