[Boost-users] [BGL] filtered_graph and null_vertex()

From: Tiago de Paula Peixoto (tiago_at_[hidden])
Date: 2005-08-13 13:37:52

Hello.

Is the function graph_traits<G>::null_vertex() defined for G =
filtered_graph? When I try to compile the following simple program:

--------------------------------------------------------------
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/filtered_graph.hpp>

using namespace boost;

int main()
{
    typedef adjacency_list<vecS> graph_t;
    typedef filtered_graph<graph_t,keep_all> f_graph_t;
    graph_traits<f_graph_t>::vertex_descriptor v =
graph_traits<f_graph_t>::null_vertex();
    return 0;
}
--------------------------------------------------------------

I get the following error with GCC 4.0.1 and boost 1.33.0:

/usr/include/boost/graph/graph_traits.hpp: In static member function
‘static typename boost::graph_traits<G>::vertex_descriptor
boost::graph_traits<G>::null_vertex() [with G = main()::f_graph_t]’:
filtered_test.cc:10:   instantiated from here
/usr/include/boost/graph/graph_traits.hpp:49: error: ‘null_vertex’ is
not a member of ‘main()::f_graph_t’

Shouldn't null_vertex() just be defined to return the null_vertex() for
the underlying graph, since the vertex descriptors are the same? Do I
miss something?

-- 
Tiago de Paula Peixoto <tiago_at_[hidden]>