On Wed, 6 Jan 2010, Emil Dotchevski wrote:

On Wed, Jan 6, 2010 at 8:20 AM, Damien Maupu wrote:

...

I write something like: typedef boost::shared_ptr<Vertex> VertexPtr; typedef boost::shared_ptr<Edge> EdgePtr; typedef adjacency_list    Graph;

It is probably not a good idea to use shared_ptr for graphs; some graphs have cycles and this will lead to leaks (if your data structure is a DAG, you're fine.)

I don't think that will be an issue -- his shared pointers link to properties; the graph structure itself is in BGL data structures. However, if the properties refer to other graph vertices or edges, there is an issue of dangling references if those objects are removed from the graph. -- Jeremiah Willcock

Hi, It's me one more time. I am still quite new to metaprogramming. I don't understand how you have a functor that "take an edge descriptor". Can you give me such example of functor? In the link you send me on "function_property_map" how should be written "get_weight" ? Thank you Damien Jeremiah Willcock a écrit :

On Wed, 6 Jan 2010, Damien Maupu wrote:

...

Dear all,

I am using bundled properties when I define my graph. The bundled properties are smart pointers to my own class Edge and Vertex. I write something like: typedef boost::shared_ptr<Vertex> VertexPtr; typedef boost::shared_ptr<Edge> EdgePtr; typedef adjacency_list Graph;

Vertex and Edge being my own classes to store information on the vertices and the edges. For what I read in the doc, this is the correct, more modern way to do it.

My problem is the following. I am trying to use the BGL algorithms and some of them require vertex/edge info to be provide as properties maps.

From http://www.boost.org/doc/libs/1_41_0/libs/graph/doc/bundles.html I know it is possible to generate those maps from bundled properties.

It works well if I don't use shared_ptr but cannot compile otherwise.

When using shared_ptr, similarly to the doc, I wrote:

typedef property_map::type WeightMap; WeightMap weightMap = get(&EdgePtr::m_cost, *_graph);

m_cost being a public float member of my own class Edge.

I have the following compilation error: 'm_cost' : is not a member of 'boost::shared_ptr<T>'

Indeed it is not. My question is, I can let the shared_ptr access the member? In other world how to deal with bundled properties / properties maps and shared_ptr.

Extra question, could 'm_cost' be a private member of my own class Edge?

Try writing a function that takes an edge descriptor and returns a reference to m_cost for that edge (using the bundled property syntax), then using the code in URL:http://article.gmane.org/gmane.comp.lib.boost.user/54397 to convert that into a property map.

BTW, sorry about referring to this message before I sent it (this is the one I was referring to about handling pointers as bundled properties). I thought I had sent it earlier.

-- Jeremiah Willcock _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users