Boost Graph Library: property

property_writer<PropertyMap, OutputIterator, EventTag>

This is an EventVisitor that can be used to output the property of a vertex or edge at some event-point within an algorithm.

property_writer can be used with graph algorithms by wrapping it with the algorithm-specific adaptor, such as bfs_visitor and dfs_visitor. Also, this event visitor can be combined with other event visitors using std::pair to form an EventVisitorList.

Example

The following is an excerpt from examples/dave.cpp.

  std::ostream_iterator cout_int(std::cout, " ");
  std::ostream_iterator cout_char(std::cout, " ");

  boost::breadth_first_search
    (G, vertex(a, G), make_bfs_visitor(
     std::make_pair(write_property(name, cout_char, on_discover_vertex()),
     std::make_pair(write_property(distance.begin(), cout_int, 
                                   on_discover_vertex()),
     std::make_pair(print_edge(name, std::cout, on_examine_edge()),
                    print_endl(std::cout, on_finish_vertex()
                    ))))));

Model of

EventVisitor

Where Defined

boost/graph/visitors.hpp

Template Parameters

Parameter Description Default

PropertyMap A ReadablePropertyMap where the key_type is the vertex descriptor type or edge descriptor of the graph (depending on the kind of event tag) and the value_type of the property is convertible to the value_type of the OutputIterator.

OutputIterator The iterator type used to write out the property values, which must be a model of OutputIterator.

EventTag The tag to specify when the property_writer should be applied during the graph algorithm.

Parameter	Description	Default
`PropertyMap`	A ReadablePropertyMap where the `key_type` is the vertex descriptor type or edge descriptor of the graph (depending on the kind of event tag) and the `value_type` of the property is convertible to the `value_type` of the `OutputIterator`.
`OutputIterator`	The iterator type used to write out the property values, which must be a model of OutputIterator.
`EventTag`	The tag to specify when the `property_writer` should be applied during the graph algorithm.

Associated Types

Type	Description
`property_writer::event_filter`	This will be the same type as the template parameter `EventTag`.

Member Functions

Member Description

property_writer(PropertyMap pa, OutputIterator out); Construct a property writer object with the property map pa and output iterator out.

template <class X, class Graph> void operator()(X x, const Graph& g); This writes the property value for x to the output iterator.
*out++ = get(pa, x);

Member	Description
`property_writer(PropertyMap pa, OutputIterator out);`	Construct a property writer object with the property map `pa` and output iterator `out`.
`template <class X, class Graph> void operator()(X x, const Graph& g);`	This writes the property value for `x` to the output iterator. `*out++ = get(pa, x);`

Non-Member Functions

Function	Description
`template <class PropertyMap, class OutputIterator, class Tag> property_writer<PropertyMap, OutputIterator, Tag> write_property(PropertyMap pa, OutputIterator out, Tag);`	A convenient way to create a `property_writer`.

property_writer<PropertyMap, OutputIterator, EventTag>