自定义BGL图需要什么才能与拓扑排序一起使用？

#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/topological_sort.hpp>

typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS> Graph;
typedef boost::graph_traits<Graph>::vertex_descriptor Vertex;

Graph g;
Vertex v1 = add_vertex(g);
Vertex v2 = add_vertex(g);
Vertex v3 = add_vertex(g);
add_edge(v1, v2, g);
add_edge(v2, v3, g);

std::vector<Vertex> topo_order;
boost::topological_sort(g, std::back_inserter(topo_order));

for (Vertex v : topo_order) {
    std::cout<< v << " ";
}

std::vector<int> component(num_vertices(g));
int num = connected_components(g, &component[0]);
if (num > 1) {
    std::cout << "Graph contains cycles or disconnected components." << std::endl;
}