Re: [Boost-users] [BGL] Is vertex_descriptor always integer?

Daniel, thank you for you answer. As you suggested, I tied to use make_iterator_property_map: std::vector pred_vec(num_vertices(g)); auto pred = make_iterator_property_map(pred_vec.begin(), get(vertex_index_t(), g)); auto rep = record_edge_predecessors(pred, on_edge_relaxed()); My code compiled for: boost::adjacency_list but not for: boost::adjacency_list Am I doing something wrong? As for another solution, my guess is that for a mapping from any kind of vertex_descriptor to edge_descriptor, one could use associative_property_map. Would that be true? Thanks & best, Irek On 04.12.2015 17:30, Daniel Hofmann wrote:

For the concept a vertex_descriptor models, take a look here:

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http://www.boost.org/doc/libs/1_59_0/libs/graph/doc/Graph.html

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A vertex descriptor corresponds to a unique vertex in an abstract graph instance. A vertex descriptor must be Default Constructible, Assignable, and Equality Comparable.

These are the guarantees you get.

I'm usually using make_iterator_property_map with a vector of the graph's vertex or edge descriptor.

Hope that helps, Daniel J H

On December 4, 2015 4:07:58 PM GMT+01:00, "Ireneusz Szcześniak" wrote:

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Hi,

In my code I do:

vector_property_map pred(num_vertices(g)); auto rep = record_edge_predecessors(pred, on_edge_relaxed()); auto dv = make_dijkstra_visitor(rep); dijkstra_shortest_paths(g, s, visitor(dv));

But this assumes that the vertex_descriptor is integer, since I'm using vector_property.

Does this assumption always hold, or should I choose the type of the property map based on the graph type?

Thanks & best, Irek _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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