st::graph_traits&lt;G&gt;::vertex_descriptor v;
    G g;
  };
</PRE>

<h3>Design Rationale</h3>

The AdjacencyGraph concept is somewhat frivolous since <a
href="./IncidenceGraph.html">IncidenceGraph</a> really covers the same
functionality (and more).  The AdjacencyGraph concept exists because
there are situations when <tt>adjacent_vertices()</tt> is more
convenient to use than <tt>out_edges()</tt>. If you are constructing a
graph class and do not want to put in the extra work of creating an
adjacency itera