// Copyright 2002 The Trustees of Indiana University.

// Use, modification and distribution is subject to the Boost Software 

// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at

// http://www.boost.org/LICENSE_1_0.txt)

//  Boost.MultiArray Library

//  Authors: Ronald Garcia

//           Jeremy Siek

//           Andrew Lumsdaine

//  See http://www.boost.org/libs/multi_array for documentation.

#ifndef BOOST_EXTENT_GEN_RG071801_HPP

#define BOOST_EXTENT_GEN_RG071801_HPP

#include "boost/multi_array/extent_range.hpp"

#include "boost/multi_array/range_list.hpp"

#include "boost/multi_array/types.hpp"

#include "boost/array.hpp"

#include <algorithm>

namespace boost {

namespace detail {

namespace multi_array {

template <std::size_t NumRanges>

class extent_gen {

public:

  typedef boost::detail::multi_array::index index;

  typedef boost::detail::multi_array::size_type size_type;

  typedef extent_range<index,size_type> range;

private:

  typedef typename range_list_generator<range,NumRanges>::type range_list;

public:

  template <std::size_t Ranges>

  struct gen_type {

    typedef extent_gen<Ranges> type;

  };

  range_list ranges_;

  extent_gen() { }

  // Used by operator[] to expand extent_gens

  extent_gen(const extent_gen<NumRanges-1>& rhs,

            const range& a_range)

  {

    std::copy(rhs.ranges_.begin(),rhs.ranges_.end(),ranges_.begin());

    *ranges_.rbegin() = a_range;

  }

  extent_gen<NumRanges+1>

  operator[](const range& a_range)

  {

    return extent_gen<NumRanges+1>(*this,a_range);    

  }

  extent_gen<NumRanges+1>

  operator[](index idx)

  {

    return extent_gen<NumRanges+1>(*this,range(0,idx));    

  }    

  static extent_gen<0> extents() {

    return extent_gen<0>();

  }

};

} // namespace multi_array

} // namespace detail

} // namespace boost

#endif // BOOST_EXTENT_GEN_RG071801_HPP