Boost Graph Library: Reverse Graph Adaptor

#

    reverse_graph<BidirectionalGraph, GraphReference>

The `reverse_graph` adaptor flips the in-edges and out-edges of a BidirectionalGraph, effectively transposing the graph. The construction of the `reverse_graph` is constant time, providing a highly efficient way to obtain a transposed view of a graph.

### Example

The example from `example/reverse_graph.cpp`.

    int
    main()
    {
      typedef boost::adjacency_list<
        boost::vecS, boost::vecS, boost::bidirectionalS,
      > Graph;

      Graph G(5);
      boost::add_edge(0, 2, G);
      boost::add_edge(1, 1, G);
      boost::add_edge(1, 3, G);
      boost::add_edge(1, 4, G);
      boost::add_edge(2, 1, G);
      boost::add_edge(2, 3, G);
      boost::add_edge(2, 4, G);
      boost::add_edge(3, 1, G);
      boost::add_edge(3, 4, G);
      boost::add_edge(4, 0, G);
      boost::add_edge(4, 1, G);

      std::cout << "original graph:" << std::endl;
      boost::print_graph(G, boost::get(boost::vertex_index, G));

      std::cout << std::endl << "reversed graph:" << std::endl;
      boost::print_graph(boost::make_reverse_graph(G),
                         boost::get(boost::vertex_index, G));

      return 0;
    }

The output is:

    original graph:
    0 --> 2
    1 --> 1 3 4
    2 --> 1 3 4
    3 --> 1 4
    4 --> 0 1

    reversed graph:
    0 --> 4
    1 --> 1 2 3 4
    2 --> 0
    3 --> 1 2
    4 --> 1 2 3

### Template Parameters

Parameter | Description | Default
--- | --- | ---
`BidirectionalGraph` | The graph type to be adapted. |
`GraphReference` | This type should be `const BidirectionalGraph&` if you want to create a const reverse graph, or `BidirectionalGraph&` if you want to create a non-const reverse graph. | `const BidirectionalGraph&`

### Model of

BidirectionalGraph and optionally VertexListGraph and PropertyGraph

### Where Defined

`boost/graph/reverse_graph.hpp`

## Associated Types

`graph_traits<reverse_graph>::vertex_descriptor`
The type for the vertex descriptors associated with the `reverse_graph`.

`graph_traits<reverse_graph>::edge_descriptor`
The type for the edge descriptors associated with the `reverse_graph`.

`graph_traits<reverse_graph>::vertex_iterator`
The type for the iterators returned by `vertices()`.

`graph_traits<reverse_graph>::edge_iterator`
The type for the iterators returned by `edges()`.

`graph_traits<reverse_graph>::out_edge_iterator`
The type for the iterators returned by `out_edges()`.

`graph_traits<reverse_graph>::adjacency_iterator`
The type for the iterators returned by `adjacent_vertices()`.

`graph_traits<reverse_graph>::directed_category`
Provides information about whether the graph is directed (`directed_tag`) or undirected (`undirected_tag`).

`graph_traits<reverse_graph>::edge_parallel_category`
This describes whether the graph class allows the insertion of parallel edges (edges with the same source and target). The two tags are `allow_parallel_edge-_tag` and `disallow_parallel_edge_tag`. The `setS` and `hash_setS` variants disallow parallel edges while the others allow parallel edges.

`graph_traits<reverse_graph>::vertices_size_type`
The type used for dealing with the number of vertices in the graph.

`graph_traits<reverse_graph>::edges_size_type`
The type used for dealing with the number of edges in the graph.

`graph_traits<reverse_graph>::degree_size_type`
The type used for dealing with the number of edges incident to a vertex in the graph.

`property_map<reverse_graph, PropertyTag>::type`
and
`property_map<reverse_graph, PropertyTag>::const_type`
The property map type for vertex or edge properties in the graph. The specific property is specified by the `PropertyTag` template argument, and must match one of the properties specified in the `VertexProperty` or `EdgeProperty` for the graph.

`property_map<reverse_graph, edge_underlying_t>::type`
and
`property_map<reverse_graph, edge_underlying_t>::const_type`
An edge property type mapping from edge descriptors in the `reverse_graph` to edge descriptors in the underlying `BidirectionalGraph` object.

## Member Functions

    reverse_graph(BidirectionalGraph& g)

Constructor. Create a reversed (transposed) view of the graph `g`.

## Non-Member Functions

    template <class BidirectionalGraph>
    reverse_graph<BidirectionalGraph, BidirectionalGraph&>
    make_reverse_graph(BidirectionalGraph& g);

    template <class BidirectionalGraph>
    reverse_graph<BidirectionalGraph, const BidirectionalGraph&>
    make_reverse_graph(const BidirectionalGraph& g)

Helper function for creating a `reverse_graph`.

    std::pair<vertex_iterator, vertex_iterator>
    vertices(const reverse_graph& g)

Returns an iterator-range providing access to the vertex set of graph `g`.

    std::pair<out_edge_iterator, out_edge_iterator>
    out_edges(vertex_descriptor v, const reverse_graph& g)

Returns an iterator-range providing access to the out-edges of vertex `v` in graph `g`. These out-edges correspond to the in-edges of the adapted graph.

    std::pair<in_edge_iterator, in_edge_iterator>
    in_edges(vertex_descriptor v, const reverse_graph& g)

Returns an iterator-range providing access to the in-edges of vertex `v` in graph `g`. These in-edges correspond to the out edges of the adapted graph.

    std::pair<adjacency_iterator, adjacency__iterator>
    adjacent_vertices(vertex_descriptor v, const reverse_graph& g)

Returns an iterator-range providing access to the adjacent vertices of vertex `v` in graph `g`.

    vertex_descriptor
    source(edge_descriptor e, const reverse_graph& g)

Returns the source vertex of edge `e`.

    vertex_descriptor
    target(edge_descriptor e, const reverse_graph& g)

Returns the target vertex of edge `e`.

    degree_size_type
    out_degree(vertex_descriptor u, const reverse_graph& g)

Returns the number of edges leaving vertex `u`.

    degree_size_type
    in_degree(vertex_descriptor u, const reverse_graph& g)

Returns the number of edges entering vertex `u`. This operation is only available if `bidirectionalS` was specified for the `Directed` template parameter.

    vertices_size_type
    num_vertices(const reverse_graph& g)

Returns the number of vertices in the graph `g`.

    vertex_descriptor
    vertex(vertices_size_type n, const reverse_graph& g)

Returns the nth vertex in the graph's vertex list.

    std::pair<edge_descriptor, bool>
    edge(vertex_descriptor u, vertex_descriptor v,
         const reverse_graph& g)

Returns the edge connecting vertex `u` to vertex `v` in graph `g`.

    template <class PropertyTag>
    property_map<reverse_graph, PropertyTag>::type
    get(PropertyTag, reverse_graph& g)

    template <class PropertyTag>
    property_map<reverse_graph, Tag>::const_type
    get(PropertyTag, const reverse_graph& g)

Returns the property map object for the vertex property specified by `PropertyTag`. The `PropertyTag` must match one of the properties specified in the graph's `VertexProperty` template argument.

    property_map<reverse_graph, edge_underlying_t>::const_type
    get(PropertyTag, const reverse_graph& g)

Returns a property map object that converts from edge descriptors in the `reverse_graph` to edge descriptors in the underlying `BidirectionalGraph` object.

    template <class PropertyTag, class X>
    typename property_traits<property_map<reverse_graph, PropertyTag>::const_type>::value_type
    get(PropertyTag, const reverse_graph& g, X x)

This returns the property value for `x`, which is either a vertex or edge descriptor.

    typename graph_traits<BidirectionalGraph>::edge_descriptor
    get(edge_underlying_t, const reverse_graph& g, edge_descriptor e)

This returns the underlying edge descriptor for the edge `e` in the `reverse_graph`.

    template <class PropertyTag, class X, class Value>
    void
    put(PropertyTag, const reverse_graph& g, X x, const Value& value)

This sets the property value for `x` to `value`. `x` is either a vertex or edge descriptor. `Value` must be convertible to `typename property_traits<property_map<reverse_graph, PropertyTag>::type>::value_type`

    template <class GraphProperties, class GraphPropertyTag>
    typename property_value<GraphProperties, GraphPropertyTag>::type&
    get_property(reverse_graph& g, GraphPropertyTag);

Return the property specified by `GraphPropertyTag` that is attached to the graph object `g`. The `property_value` traits class is defined in `boost/pending/property.hpp`.

    template <class GraphProperties, class GraphPropertyTag>
    const typename property_value<GraphProperties, GraphPropertyTag>::type&
    get_property(const reverse_graph& g, GraphPropertyTag);

Return the property specified by `GraphPropertyTag` that is attached to the graph object `g`. The `property_value` traits class is defined in `boost/pending/property.hpp`.

Copyright © 2000-2001 | Dave Abrahams (david.abrahams@rcn.com) Jeremy Siek, Indiana University (jsiek@osl.iu.edu)