boost/boost/property_map_iterator.hpp

   1 // (C) Copyright Jeremy Siek, 2001. Permission to copy, use, modify,
   2 // sell and distribute this software is granted provided this
   3 // copyright notice appears in all copies. This software is provided
   4 // "as is" without express or implied warranty, and with no claim as
   5 // to its suitability for any purpose.
   6
   7 //  See http://www.boost.org/libs/property_map for documentation.
   8
   9 #ifndef BOOST_PROPERTY_MAP_ITERATOR_HPP
  10 #define BOOST_PROPERTY_MAP_ITERATOR_HPP
  11
  12 #include <boost/property_map.hpp>
  13 #include <boost/iterator/iterator_adaptor.hpp>
  14 #include <boost/mpl/if.hpp>
  15 #include <boost/type_traits/is_same.hpp>
  16
  17 namespace boost {
  18
  19   //======================================================================
  20   // property iterator, generalized from ideas by François Faure
  21
  22   namespace detail {
  23
  24     template <class Iterator, class LvaluePropertyMap>
  25     class lvalue_pmap_iter
  26       : public iterator_adaptor< lvalue_pmap_iter< Iterator, LvaluePropertyMap >,
  27                                  Iterator,
  28                                  typename property_traits<LvaluePropertyMap>::value_type,
  29                                  use_default,
  30                                  typename property_traits<LvaluePropertyMap>::reference>
  31     {
  32       friend class boost::iterator_core_access;
  33
  34       typedef iterator_adaptor< lvalue_pmap_iter< Iterator, LvaluePropertyMap >,
  35                                 Iterator,
  36                                 typename property_traits<LvaluePropertyMap>::value_type,
  37                                 use_default,
  38                                 typename property_traits<LvaluePropertyMap>::reference> super_t;
  39
  40     public:
  41       lvalue_pmap_iter() { }
  42       lvalue_pmap_iter(Iterator const&     it,
  43                        LvaluePropertyMap m)
  44         : super_t(it),
  45           m_map(m) {}
  46
  47     private:
  48       typename lvalue_pmap_iter::reference
  49       dereference() const
  50       {
  51         return m_map[*(this->base_reference())];
  52       }
  53
  54       LvaluePropertyMap m_map;
  55     };
  56
  57     template <class Iterator, class ReadablePropertyMap>
  58     class readable_pmap_iter :
  59       public iterator_adaptor< readable_pmap_iter< Iterator, ReadablePropertyMap >,
  60                                Iterator,
  61                                typename property_traits<ReadablePropertyMap>::value_type,
  62                                use_default,
  63                                typename property_traits<ReadablePropertyMap>::value_type>
  64
  65
  66     {
  67       friend class iterator_core_access;
  68
  69       typedef iterator_adaptor< readable_pmap_iter< Iterator, ReadablePropertyMap >,
  70                                 Iterator,
  71                                 typename property_traits<ReadablePropertyMap>::value_type,
  72                                 use_default,
  73                                 typename property_traits<ReadablePropertyMap>::value_type> super_t;
  74
  75     public:
  76       readable_pmap_iter() { }
  77       readable_pmap_iter(Iterator const&     it,
  78                          ReadablePropertyMap m)
  79         : super_t(it),
  80           m_map(m) {}
  81
  82     private:
  83       typename readable_pmap_iter::reference
  84       dereference() const
  85       {
  86         return get(m_map, *(this->base_reference()));
  87       }
  88
  89       ReadablePropertyMap m_map;
  90     };
  91
  92
  93   } // namespace detail
  94
  95   template <class PropertyMap, class Iterator>
  96   struct property_map_iterator_generator :
  97     mpl::if_< is_same< typename property_traits<PropertyMap>::category, lvalue_property_map_tag>,
  98               detail::lvalue_pmap_iter<Iterator, PropertyMap>,
  99               detail::readable_pmap_iter<Iterator, PropertyMap> >
 100   {};
 101
 102   template <class PropertyMap, class Iterator>
 103   typename property_map_iterator_generator<PropertyMap, Iterator>::type
 104   make_property_map_iterator(PropertyMap pmap, Iterator iter)
 105   {
 106     typedef typename property_map_iterator_generator<PropertyMap,
 107       Iterator>::type Iter;
 108     return Iter(iter, pmap);
 109   }
 110
 111 } // namespace boost
 112
 113 #endif // BOOST_PROPERTY_MAP_ITERATOR_HPP
 114