#

    astar_heuristic<Graph, CostType>

This class is a default implementation of the AStarHeuristic concept. It implements a "zero" heuristic -- a heuristic function that returns a cost of zero regardless of the vertex it is passed.

### Model of

AStarHeuristic

### Template Parameters

Parameter | Description | Default
--- | --- | ---
`Graph` | The type of the graph being searched. |
`CostType` | A type that can be used with the `compare` and `combine` functions passed to A*. Typically an integer or floating point type. |

### Where Defined

`boost/graph/astar_search.hpp`

### Member Functions

This class implements the single member function required by AStarHeuristic:

Function | Description
--- | ---
`CostType operator()(graph_traits<Graph>::vertex_descriptor u);` | Called for the target of every out edge of a vertex being examined. Returns the cost, estimated by the heuristic, from vertex `u` to a goal.

Copyright © 2004 | Kristopher Beevers, Rensselaer Polytechnic Institute (beevek@cs.rpi.edu)