title: find multiple edges given 2 vertices in BOOST graph
body: <p>I am using Boost Graph library for some project and i want to find number of times an edge is repeated in a graph. for example, </p>
  
  <pre><code>typedef boost::adjacency_list&lt;boost::vecS, boost::vecS, boost::undirectedS, Node_Info, Edge_Info &gt; Graph_t;  
  //node_info and Edge_info are external node and edge properties (structures)
  </code></pre>
  
  <p>suppose if i have two nodes, node1 and node2 and there is an edge between them (node1, node2). edge property for each edge contains a timestamp start, end.. and there can be many such edges in the graph with different timestamps. for example. </p>
  
  <pre><code>edge1 = (node1, node2) with start = 100, end = 200.
  edge2 = (node1, node2) with start = 250, end = 400.
  </code></pre>
  
  <p>I know that in a boost graph, given two vertices, we can find whether an edge exists in the graph or not using the following. </p>
  
  <pre><code>std::pair &lt; edge_t, bool &gt; p = boost::edge( node1, node2, myGraph );
  if(p.second == 1)  cout &lt;&lt; "edge exists!" &lt;&lt; endl;
  else cout &lt;&lt; " does not exist " &lt;&lt; endl;
  </code></pre>
  
  <p>But this could mean that it would only return any one edge even if multiple edges exist  with different edge properties --> PROBLEM</p>
  
  <p>can anyone suggest an idea how to get such multiple edges between two given nodes? Thanks!</p>