Re: Graph - return edge_descriptor (side-note)

On Thu, 2002-08-22 at 10:19, Shaw, Richard A wrote:

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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

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It the returns the edge The main code prints out the edge descriptor and the fails when

In my last mail I didn't say how it failed. It gets a bad address for the property - so for the weight it displays a large meaningless number, for a string property it prints pages of garbage - I was surprised how few zeros were in memory ! I had a look at the implementation of edge() and I see that it returns the following - edge_descriptor(u, v, &(*i).get_property() my code just returns the contents of the out_edge_iterator I changed my function to return - return std::make_pair(true, graph_traits<Graph>::edge_descriptor(u, v, (*ei).get_property())); but it made no difference. I tried using edge() and it works OK. Strange. --- In Boost-Users@y..., Tarjei Knapstad wrote: the edge trying to

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print the weight.

BTW - Is there a ready made function to find an edge based on the vertices ?

#include #include <iostream> #include <fstream>

#include #include #include

using namespace boost;

// Find edge template <class Graph> std::pair 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