#

    property_put<PropertyMap, EventTag>

This is an EventVisitor that can be used to write a fixed value to a property map when a vertex or edge is visited at some event-point within an algorithm. For example, this visitor can be used as an alternative to a loop to initialize a property map, or it can be used to mark only back edges with a property.

`property_put` 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

      boost::depth_first_search
        (G, boost::visitor(
              boost::make_dfs_visitor(
                boost::put_property(is_back_edge, boost::on_back_edge()))));

### Model of

EventVisitor

### Where Defined

`boost/graph/visitors.hpp`

### Template Parameters

Parameter | Description | Default
--- | --- | ---
`PropertyMap` | A WritablePropertyMap, where the `key_type` is the vertex descriptor type or edge descriptor of the graph (depending on the kind of event tag). |
`EventTag` | The tag to specify when the `property_put` should be applied during the graph algorithm. |

## Associated Types

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

### Member Functions

Member | Description
--- | ---
`property_put(PropertyMap pa, property_traits::value_type val);` | Construct a property put object with the property map `pa` and constant value `val`.
`template <class X, class Graph> void operator()(X x, const Graph& g);` | This puts the value `val` into the property map for the vertex or edge `x`.

### Non-Member Functions

Function | Description
--- | ---
`template <class PropertyMap, class EventTag> property_put<PropertyMap, EventTag> put_property(PropertyMap pa, typename property_traits::value_type val, EventTag);` | A convenient way to create a `property_put`.

### See Also

Visitor concepts

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

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)
Copyright © 2010 | Matthias Walter (xammy@xammy.homelinux.net)
| Trustees of Indiana University