Re: [Boost-users] Retrieving edge weights

Subject: Re: [Boost-users] Retrieving edge weights
From: Jeremiah Willcock (jewillco_at_[hidden])
Date: 2011-06-11 17:12:33

On Sat, 11 Jun 2011, David Doria wrote:

> I found one way to get edge weights:
>
>  typedef boost::property_map<Graph, boost::edge_weight_t>::type EdgeWeightMap;
>  EdgeWeightMap edgeWeightMap = get(boost::edge_weight, g);
>
>  std::pair<Graph::edge_descriptor, bool> edgePair = boost::edge(v0, v1, g);
>  Graph::edge_descriptor edge = edgePair.first;
>
> That seems like a lot of work though. It looks like there is a
> operator[](edge_descriptor), but I don't understand how to use it:
>
> I tried:
>
> g[edge]->edge_weight

That syntax only works for bundled properties.  If you had used a struct 
with an edge_weight member as your vertex property type, you could use the 
[] syntax.  With the old-style property syntax, however, you will need to 
use the version you posted at the top.  You can use a three-parameter 
version of get (get(boost::edge_weight, g, v) is the order, I think) if 
you are not getting a lot of weights.

-- Jeremiah Willcock