title: About the astar algorithm in boost graph library
body: <p>I found this A star algorithm implementation of boost <a href="http://www.boost.org/doc/libs/1_38_0/libs/graph/doc/astar_search.html" rel="nofollow">http://www.boost.org/doc/libs/1_38_0/libs/graph/doc/astar_search.html</a> particularly the example <a href="http://www.boost.org/doc/libs/1_38_0/libs/graph/example/astar-cities.cpp" rel="nofollow">http://www.boost.org/doc/libs/1_38_0/libs/graph/example/astar-cities.cpp</a>.</p>
  
  <p>When I used that example on my graph, I found that the edges are not directed. I mean in certain cases my edges are directed, however, it seems that it ignores it. How, can I modify to make it directed</p>