Hello, I like the named parameter method to define graph properties, so all our properties are concentrated in a struct. But, I'd like add a vertex with specific properties are already defined: //======================= #include <iostream> #include <string> #include #include using namespace std; using namespace boost; struct People { People () { } People (string const& n, int a) : name(n), age(a) { } string name; int age; }; int main(int, char**) { typedef adjacency_list< vecS, vecS, bidirectionalS, People > Graph; typedef graph_traits< Graph >::vertex_descriptor vertex_descriptor; Graph g; vertex_descriptor v; People n ("toto", 26); v = add_vertex (g); // this use the default ctor of People, a add_vertex(g, n) g[v] = n; // will be more efficiently (avoid a People assignment) cout << g[v].name << " is " << g[v].age << " old." << endl; } //======================= -- Johan