Boost Graph Library: bfs_visitor

#

    bfs_visitor<EventVisitorList>

This class is an adapter that converts a list of EventVisitors (constructed using `std::pair`) into a BFSVisitor.

### Example

This is an excerpt from `examples/bfs.cpp` where three event-visitors are combined to make a BFS visitor. The functions `boost::record_distances`, `boost::record_predecessors`, and `copy_graph` are all functions that create an event visitor.

      // Construct graph G and obtain the source vertex s ...

      boost::breadth_first_search(G, s,
       boost::make_bfs_visitor(
        std::make_pair(boost::record_distances(d, boost::on_tree_edge()),
        std::make_pair(boost::record_predecessors(p.begin(),
                                                  boost::on_tree_edge()),
                       copy_graph(G_copy, boost::on_examine_edge())))) );

### Model of

BFSVisitor

### Template Parameters

Parameter | Description | Default
--- | --- | ---
`EventVisitorList` | A list of EventVisitor's created with `std::pair`. | `null_visitor`

### Where Defined

`boost/graph/breadth_first_search.hpp`

### Member Functions

This class implements all of the member functions required by BFSVisitor. In each function the appropriate event is dispatched to the EventVisitor in the EventVisitorList.

### Non-Member Functions

Function | Description
--- | ---
`template <class EventVisitorList> bfs_visitor<EventVisitorList> make_bfs_visitor(EventVisitorList ev_list);` | Returns the event visitor list adapted to be a BFS visitor.

### See Also

Visitor concepts

The following are event visitors: `predecessor_recorder`, `distance_recorder`, `time_stamper`, and `property_writer`.

Copyright © 2000-2001 | Jeremy Siek, Indiana University (jsiek@osl.iu.edu) Lie-Quan Lee, Indiana University (llee@cs.indiana.edu) Andrew Lumsdaine, Indiana University (lums@osl.iu.edu)