// 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