#ifndef VARIABLE_LIST_HPP_INCLUDED
#define VARIABLE_LIST_HPP_INCLUDED

#include <boost/mpl/apply.hpp>
#include <boost/mpl/empty_base.hpp>
#include <boost/mpl/fold.hpp>
#include <boost/mpl/identity.hpp>
#include <boost/mpl/inherit.hpp>
#include <boost/mpl/joint_view.hpp>
#include <boost/mpl/lambda.hpp>
#include <boost/mpl/pair.hpp>
#include <boost/mpl/transform.hpp>
#include <boost/mpl/vector.hpp>

template <typename T, typename Op>
class variable_list_member
{
public:
  typedef typename boost::mpl::apply1<Op,T>::type member_type;
  member_type& get() { return member_; }
  const member_type& get() const { return member_; }
private:
  member_type member_;
};

template<typename Sequence,typename Op=boost::mpl::identity<boost::mpl::_> >
class variable_list:
  private boost::mpl::fold<
    Sequence,
    boost::mpl::empty_base,
    boost::mpl::inherit<
      boost::mpl::_1,
      variable_list_member<
        boost::mpl::_2,
        typename boost::mpl::lambda<Op>::type
      >
    >
  >::type
{
  typedef typename boost::mpl::lambda<Op>::type op_type;
public:
  template<typename T>
  typename variable_list_member<T,op_type>::member_type & get()
  {
    return static_cast<variable_list_member<T,op_type>&>(*this).get();
  }
  template<typename T>
  const typename variable_list_member<T,op_type>::member_type & get()const
  {
    return static_cast<const variable_list_member<T,op_type>&>(*this).get();
  }
};

#endif // VARIABLE_LIST_HPP_INCLUDED