hi list I am developping a scheduling algorithm using boost When probleme is that I want to use the adresses of boost nodes. I have writen this code. then I put the node number 2 in the ready tasks list and the iterator make the next iteration , I found that the node number 3 is in the ready list. any advice will be helpful thanks void allocate2(Graph &g,vector<MACHINE> &m,fstream &f){ ///////////////////////////// declarations /////////////////////////////// cerr << "in function allocate 2 " << endl; typedef typename property_map::type NamePA; NamePA name = get(vertex_first_name, g); typedef typename boost::property_traits<NamePA>::value_type NameType; typename boost::property_map::type id = get(vertex_index, g); typedef typename boost::graph_traits<Graph>::vertex_descriptor vertex; NameType src_name; typename boost::graph_traits<Graph>::vertex_iterator vi; list readyTasks; ///////////////////////// initialisation ///////////////////// for (vi=vertices(g).first;vi!=vertices(g).second;++vi){ if (in_degree(*vi,g)==0){ vertex v = *vi; readyTasks.push_back(&v); } } for (list::iterator it=readyTasks.begin(); it!=readyTasks.end(); ++it){ vertex *temp = *it; cerr << name[*temp].Id()<< endl; } while(readyTasks.size()){ vertex *head=readyTasks.front(); vector<int> times(m.size()); //////////////// determine the best allocations time for (int i=0;i::iterator itr=readyTasks.begin();itr!=readyTasks.end();++itr){ vertex *currentRt = *itr; cerr << "\t\ttraitement de la tache "<