#

    time_stamper<TimeMap, TimeT, EventTag>

This is an EventVisitor that can be used to "stamp" a time at some event-point within an algorithm. An example of this is recording the discover or finish time of a vertex during a graph search.

`time_stamper` 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 example shows the usage of the `time_stamper`.

      std::vector color(num_vertices(G));
      std::vector dtime(num_vertices(G));
      std::vector ftime(num_vertices(G));

      int time = 0;
      boost::breadth_first_search
        (G, vertex(s, G), make_bfs_visitor(
         std::make_pair(stamp_times(dtime.begin(), time, on_discover_vertex()),
                        stamp_times(ftime.begin(), time, on_finish_vertex()))),
         color.begin());

### Model of

EventVisitor

### Where Defined

`boost/graph/visitors.hpp`

### Template Parameters

Parameter | Description | Default
--- | --- | ---
`TimeMap` | A WritablePropertyMap, where the `key_type` is the vertex descriptor type or edge descriptor of the graph (depending on the kind of event tag), and where the `TimeT` type is convertible to the `value_type` of the time property map. |
`TimeT` | The type for the time counter, which should be convertible to the `value_type` of the time property map |
`EventTag` | The tag to specify when the `time_stamper` should be applied during the graph algorithm. |

## Associated Types

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

### Member Functions

Member | Description
--- | ---
`time_stamper(TimeMap time_pa, TimeT& t);` | Construct a time stamper object with time property map `time_pa` and time counter `t`.
`template <class X, class Graph> void operator()(X x, const Graph& g);` | This increments the time count and "stamps" the time: `put(time_pa, x, ++t);`

### Non-Member Functions

Function | Description
--- | ---
`template <class TimeMap, class TimeT, class Tag> time_stamper<TimeMap, TimeT, Tag> stamp_times(TimeMap pa, TimeT& t, Tag);` | A convenient way to create a `time_stamper`.

### See Also

Visitor concepts

The following are other event visitors: `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)