Re: [boost] [property_map, graph] optional properties

Hello, If i understand correctly, what you're asking is to be able to detect if a property is part of a graph or not.

edge_weight_property_map = get(edge_weight, graph); if (edge_weight_property_map ) {...}

It's pretty clear in the example you've given that this information is held by the type of the object "edge_weight_property_map". So the bool() operator you're asking for is, in my opinion, not necessary. Play a bit with boost::enable_if and boost::property_map<Graph, edge_weight_t> and you should be able to do what you want. Benoît