> in graph <tt>g</tt>.<br>
(Required by <a href="AdjacencyMatrix.html">AdjacencyMatrix</a>.)

<hr>
<pre>
std::pair&lt;edge_descriptor, bool&gt;
add_edge(vertex_descriptor u, vertex_descriptor v,
         adjacency_matrix&amp; g)
</pre>
  Adds edge <tt>(u,v)</tt> to the graph and returns the edge descriptor for
  the new edge. If the edge is already in the graph then a duplicate
  will not be added and the <tt>bool</tt> flag will be <tt>false</tt>.
  This operation does not invalidate any of the graph's iter