d from a <tt>std::vector</tt>
  of edge descriptors of size <tt>num_vertices(g)</tt> and
  using the <tt>i_map</tt> for the index map.
</blockquote>

UTIL: <tt>distance_map(DistanceMap d_map)</tt> 
<blockquote>
  The shortest path weight from the source vertex <tt>s</tt> to each
  vertex in the graph <tt>g</tt> is recorded in this property map. The
  shortest path weight is the sum of the edge weights along the
  shortest path.  The type <tt>DistanceMap</tt> must be a model of <a
  href="../../property_map/