ith the Parallel BGL), we can
state that a <tt class="docutils literal"><span class="pre">City</span></tt> can be constructed directly from the name of the
city using its second constructor:</p>
<pre class="literal-block">
namespace boost { namespace graph {

template&lt;&gt;
struct internal_vertex_constructor&lt;City&gt;
{
  typedef vertex_from_name&lt;City&gt; type;
};

} }
</pre>
<p>Now, one can add edges by vertex name freely, without worrying about
the explicit addition of vertices. The <tt class="docu