Look at the following code, as you it print out: ----------- name: graph name sg1: subgraph 3 name sg2: subgraph 3 name sg3: subgraph 3 ----------- when I waiting for ----------- name: graph name sg1: subgraph 1 name sg2: subgraph 2 name sg3: subgraph 3 ----------- WHY? Is this a bug in the library? #include <string> #include <iostream> using namespace std; #include <boost/config.hpp> #include <boost/graph/graphviz.hpp> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/graph_utility.hpp> int main() { boost::GraphvizDigraph gr; boost::get_property(gr, boost::graph_name) = "graph"; std::cout << "name: " << get_property(gr, boost::graph_name) << std::endl; boost::subgraph<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::GraphvizVertexProperty, boost::GraphvizEdgeProperty, boost::GraphvizGraphProperty, boost::listS> > sg1 = gr.create_subgraph(); get_property(sg1, boost::graph_name) = "subgraph 1"; boost::subgraph<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::GraphvizVertexProperty, boost::GraphvizEdgeProperty, boost::GraphvizGraphProperty, boost::listS> > sg2 = gr.create_subgraph(); get_property(sg2, boost::graph_name) = "subgraph 2"; boost::subgraph<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::GraphvizVertexProperty, boost::GraphvizEdgeProperty, boost::GraphvizGraphProperty, boost::listS> > sg3 = gr.create_subgraph(); get_property(sg3, boost::graph_name) = "subgraph 3"; std::cout << "name sg1: " << get_property(sg1, boost::graph_name) << std::endl; std::cout << "name sg2: " << get_property(sg2, boost::graph_name) << std::endl; std::cout << "name sg3: " << get_property(sg3, boost::graph_name) << std::endl; }