Iterator problem with adjacent_vertices

From: EJ van Eijk (kojak_at_[hidden])
Date: 2002-07-28 02:10:55

Hello,

I'm currently implementing some algorithms for drawing graphs, using
boost::graph. PropertyMaps e.a. are working like a charm, but for my
algorithm I need to find the adjacent vertices. Now I've become stuck
on the following:

typedef boost::adjacency_list < boost::mapS,
                                   boost::vecS,
                                boost::undirectedS,
                                VertexProperty,
                                EdgeProperty> Graph;
typedef boost::graph_traits<Graph>::vertex_descriptor Vertex;
class functor {
 ...
        void operator()(Vertex& v) { ... };
};

for_each(adjacent_vertices(u,g).first,
        adjacent_vertices(u,g).second,
        functor<Graph>(g));

complains about
foo.cc:30: initialization of non-const reference type `Vertex &'
foo.cc:30: from rvalue of type `unsigned int'

But, when using vertices(g) instead of adjacent_vertices(v,g), the
code compiles, and applies functor to each vertex.

What am I missing? The documentation is quite thorough, but I'm lost at the
moment...

EJ