title: Apply algorithms considering a specific edge subset
body: <p>I've got a huge graph with typed edge (i.e. edge with a type property). Say  </p>
  
  <pre><code>typedef adjacency_list&lt;vecS, vecS, vertex_prop, edge_prop&gt; Graph;  
  </code></pre>
  
  <p>The "type" of the edge is a member of edge_prop and has a value in {A,B,C,D},<br>
  I'd like to run the breadth first search algorithm considering only edges of type A or B.<br>
  How would you do that?  </p>