Re: [Boost-Users] Graph - return edge_descriptor (side-note)

From: Tarjei Knapstad (tarjeik_at_[hidden])
Date: 2002-08-22 15:32:37

On Thu, 2002-08-22 at 10:19, Shaw, Richard A wrote:
> Can anybody tell my why the find_edge function in the code below fails to
> get a property if I return the first edge in the list.
> 
> This is what happens -
> 
> Find_edge looks for edge A - B
> It winds it and prints out the edge descriptor, and the weight of the edge
> It the returns the edge
> The main code prints out the edge descriptor and the fails when trying to
> print the weight.
> 
> BTW - Is there a ready made function to find an edge based on the vertices ?
> 
> #include <boost/config.hpp>
> #include <iostream>
> #include <fstream>
> 
> #include <boost/graph/graph_traits.hpp>
> #include <boost/graph/adjacency_list.hpp>
> #include <boost/graph/dijkstra_shortest_paths.hpp>
> 
> using namespace boost;
> 
> // Find edge
> template <class Graph>
> std::pair<bool, graph_traits<Graph>::edge_descriptor>
> find_edge(graph_traits<Graph>::vertex_descriptor u,
> graph_traits<Graph>::vertex_descriptor v,
> 	Graph g)

It's a lot more efficient to pass a const reference to 
the graph you're searching in.

As Jeremy though, I cannot reproduce your problem using gcc 3.1 and
either of boost 1.2.8 or the latest CVS source tree.

Regards,
Tarjei