ceph/src/boost/libs/graph/include/boost/graph/property_maps/container_property_map.hpp

   1 // (C) Copyright 2007-2009 Andrew Sutton
   2 //
   3 // Use, modification and distribution are subject to the
   4 // Boost Software License, Version 1.0 (See accompanying file
   5 // LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #ifndef BOOST_GRAPH_CONTAINER_PROPERTY_MAP_HPP
   8 #define BOOST_GRAPH_CONTAINER_PROPERTY_MAP_HPP
   9
  10 #include <boost/graph/detail/index.hpp>
  11 #include <boost/property_map/property_map.hpp>
  12
  13 namespace boost
  14 {
  15     // This is an adapter built over the iterator property map with
  16     // more useful uniform construction semantics. Specifically, this
  17     // requires the container rather than the iterator and the graph
  18     // rather than the optional index map.
  19     template <typename Graph, typename Key, typename Container>
  20     struct container_property_map
  21         : public boost::put_get_helper<
  22                 typename iterator_property_map<
  23                         typename Container::iterator,
  24                         typename property_map<
  25                                 Graph,
  26                                 typename detail::choose_indexer<Graph, Key>::index_type
  27                             >::type
  28                     >::reference,
  29                     container_property_map<Graph, Key, Container>
  30             >
  31     {
  32         typedef typename detail::choose_indexer<Graph, Key>::indexer_type indexer_type;
  33         typedef typename indexer_type::index_type index_type;
  34         typedef iterator_property_map<
  35                 typename Container::iterator,
  36                 typename property_map<Graph, index_type>::type
  37             > map_type;
  38         typedef typename map_type::key_type key_type;
  39         typedef typename map_type::value_type value_type;
  40         typedef typename map_type::reference reference;
  41         typedef typename map_type::category category;
  42
  43         // The default constructor will *probably* crash if its actually
  44         // used for referencing vertices since the underlying iterator
  45         // map points past the end of an unknown container.
  46         inline container_property_map()
  47             : m_map()
  48         { }
  49
  50         // This is the preferred constructor. It is invoked over the container
  51         // and the graph explicitly. This requires that the underlying iterator
  52         // map use the indices of the vertices in g rather than the default
  53         // identity map.
  54         //
  55         // Note the const-cast this ensures the reference type of the
  56         // vertex index map is non-const, which happens to be an
  57         // artifact of passing const graph references.
  58         inline container_property_map(Container& c, const Graph& g)
  59             : m_map(c.begin(), indexer_type::index_map(const_cast<Graph&>(g)))
  60         { }
  61
  62         // Typical copy constructor.
  63         inline container_property_map(const container_property_map& x)
  64             : m_map(x.m_map)
  65         { }
  66
  67         // The [] operator delegates to the underlying map/
  68         inline reference operator [](const key_type& k) const
  69         { return m_map[k];  }
  70
  71         map_type m_map;
  72     };
  73 }
  74
  75 #endif