title: How to modify properties while proceeding BFS in Boost Graph Library?
body: <p>I'm using bundled property for a graph. Definitions are as follows:<br></p>
  
  <pre><code>class Node
  {
      void AssignPlane(Plane&amp; p)
      Plane* dp;
      double errors;
  }
  
  void Node::AssignPlane(Plane&amp; p)
  {
      dp=&amp;p;
      errors=p.a+p.b+p.c;// simplified
  }
  
  typedef adjacency_list&lt;vecS,vecS,bidirectionalS,Node,float&gt; NGraph;
  
  //...
  
  struct NVisitor: default_bfs_visitor
  {
      void discover_vertex(VertexDesc u, const NGraph&amp; g) const
      {
          // CAN'T MODIFY G
      }
  }
  </code></pre>
  
  <p>But I can't simply call g[u].AssignPlane(p) to modify a vertex, nor can I get the pointer to the vertex, which are both vital to me. <br>
  Though this question may seem to be stupid, as a novice of Boost, and have fought two weeks to adapt to the convoluted style of Boost codes, I really need help. <br>
  Do not try to answer "You need to use something other than BGL", please, as I can find nothing to support my work other than BGL. <br>
  And I must also say, the official documentation is not intended to explain their great work in a simpler way. Since I have read the documentation for dozens of times, do not suggest me to reread the documentation. <br>
  I will appreciate any useful help, and say thank you in advance. </p>