DataWeightProxy.h

#ifndef _theplu_yat_utility_data_weight_proxy_
#define _theplu_yat_utility_data_weight_proxy_ 

// $Id: DataWeightProxy.h 2375 2010-12-13 03:28:46Z peter $

/*
  Copyright (C) 2008 Jari Häkkinen, Peter Johansson
  Copyright (C) 2009, 2010 Peter Johansson

  This file is part of the yat library, http://dev.thep.lu.se/yat

  The yat library is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License as
  published by the Free Software Foundation; either version 3 of the
  License, or (at your option) any later version.

  The yat 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
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with yat. If not, see <http://www.gnu.org/licenses/>.
*/

#include "DataWeight.h"

#include <boost/concept/assert.hpp>

#include <iterator>

namespace theplu {
namespace yat {
namespace utility {

  template<typename DataIterator, typename WeightIterator>
  class DataWeightProxy
  {
  public:
    DataWeightProxy(DataIterator data, WeightIterator weight)
      : data_(data), weight_(weight) 
    {
      using boost::Convertible;
      // DataIterator::value must be convertible to double
      BOOST_CONCEPT_ASSERT((Convertible<data_type, double>));
      // this is for function data(void) const
      BOOST_CONCEPT_ASSERT((Convertible<data_reference, const double&>));

      // same check for WeightIterator
      BOOST_CONCEPT_ASSERT((Convertible<weight_type, double>));
      BOOST_CONCEPT_ASSERT((Convertible<weight_reference, const double&>));
    }

    typename std::iterator_traits<DataIterator>::reference data(void) 
    { 
      BOOST_CONCEPT_ASSERT((boost::Convertible<data_reference, double>));
      return *data_; 
    }

    const double& data(void) const { return *data_ ; }

    typename std::iterator_traits<WeightIterator>::reference weight(void) 
    { 
      BOOST_CONCEPT_ASSERT((boost::Convertible<weight_reference, double>));
      return *weight_; 
    }

    const double& weight(void) const { return *weight_; }

    DataWeightProxy& operator=(const DataWeightProxy& rhs)
    {
      data() = rhs.data();
      weight() = rhs.weight();
      return *this;
    }

    DataWeightProxy& operator=(const DataWeight& rhs)
    {
      data() = rhs.data();
      weight() = rhs.weight();
      return *this;
    }

    operator DataWeight() const 
    { return DataWeight(this->data(), this->weight()); }

  private:
    DataIterator data_;
    WeightIterator weight_;

    typedef std::iterator_traits<DataIterator> data_traits;
    typedef typename data_traits::value_type data_type;
    typedef typename data_traits::reference data_reference;

    typedef std::iterator_traits<WeightIterator> weight_traits;
    typedef typename weight_traits::value_type weight_type;
    typedef typename weight_traits::reference weight_reference;

    // using compiler generated copy
    //DataWeightProxy(const DataWeightProxy&);
  };

}}} // of namespace utility, yat, and theplu

#endif