// (C) Copyright Jeremy Siek, 2001.

// Distributed under 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)

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

#ifndef BOOST_PROPERTY_MAP_ITERATOR_HPP

#define BOOST_PROPERTY_MAP_ITERATOR_HPP

#include <boost/property_map.hpp>

#include <boost/iterator/iterator_adaptor.hpp>

#include <boost/mpl/if.hpp>

#include <boost/type_traits/is_same.hpp>

namespace boost {

  //======================================================================

  // property iterator, generalized from ideas by François Faure

  namespace detail {

    template <class Iterator, class LvaluePropertyMap>

    class lvalue_pmap_iter

      : public iterator_adaptor< lvalue_pmap_iter< Iterator, LvaluePropertyMap >,

                                 Iterator,

                                 typename property_traits<LvaluePropertyMap>::value_type,

                                 use_default,

                                 typename property_traits<LvaluePropertyMap>::reference>

    {

      friend class boost::iterator_core_access;

      typedef iterator_adaptor< lvalue_pmap_iter< Iterator, LvaluePropertyMap >,

                                Iterator,

                                typename property_traits<LvaluePropertyMap>::value_type,

                                use_default,

                                typename property_traits<LvaluePropertyMap>::reference> super_t;

    public:

      lvalue_pmap_iter() { }

      lvalue_pmap_iter(Iterator const&     it,

                       LvaluePropertyMap m)

        : super_t(it),

          m_map(m) {}

    private:

      typename super_t::reference

      dereference() const

      {

        return m_map[*(this->base_reference())];

      }

      LvaluePropertyMap m_map;

    };

    template <class Iterator, class ReadablePropertyMap>

    class readable_pmap_iter :

      public iterator_adaptor< readable_pmap_iter< Iterator, ReadablePropertyMap >,

                               Iterator,

                               typename property_traits<ReadablePropertyMap>::value_type,

                               use_default,

                               typename property_traits<ReadablePropertyMap>::value_type>

    {

      friend class boost::iterator_core_access;

      typedef iterator_adaptor< readable_pmap_iter< Iterator, ReadablePropertyMap >,

                                Iterator,

                                typename property_traits<ReadablePropertyMap>::value_type,

                                use_default,

                                typename property_traits<ReadablePropertyMap>::value_type> super_t;

    public:

      readable_pmap_iter() { }

      readable_pmap_iter(Iterator const&     it,

                         ReadablePropertyMap m)

        : super_t(it),

          m_map(m) {}

    private:

      typename super_t::reference

      dereference() const

      {

        return get(m_map, *(this->base_reference()));

      }

      ReadablePropertyMap m_map;

    };

  } // namespace detail

  template <class PropertyMap, class Iterator>

  struct property_map_iterator_generator :

    mpl::if_< is_same< typename property_traits<PropertyMap>::category, lvalue_property_map_tag>,

              detail::lvalue_pmap_iter<Iterator, PropertyMap>,

              detail::readable_pmap_iter<Iterator, PropertyMap> >

  {};

  template <class PropertyMap, class Iterator>

  typename property_map_iterator_generator<PropertyMap, Iterator>::type

  make_property_map_iterator(PropertyMap pmap, Iterator iter)

  {

    typedef typename property_map_iterator_generator<PropertyMap, 

      Iterator>::type Iter;

    return Iter(iter, pmap);

  }

} // namespace boost

#endif // BOOST_PROPERTY_MAP_ITERATOR_HPP