Hello, I want to put edge label but facing an error. Please share any better idea. Thanks in advance. YASIN ======================= My graph is: namespace boost { struct computable_object_t { typedef vertex_property_tag kind; }; } typedef boost::property > slVertexProperty; typedef boost::property> slEdgeProperty; typedef boost::adjacency_list slGraph; slGraph graph; .... ... //Now i want to add edge name boost::property_map::type labelmap = get(edge_name, graph); for(tie(ei, ei_end) = edges(graph); ei != ei_end; ++ei){ string label = "unknown"; put(labelmap, *ei, label); cout<<"\nUndirected s: "< E:\ProBT22\boost_1_46_1\boost/pending/detail/property.hpp(21): could be 'boost::detail::error_property_not_found &boost::detail::error_property_not_found::operator =(const boost::detail::error_property_not_found &)' 1> while trying to match the argument list '(boost::detail::error_property_not_found, const std::string)' 1> MMHC\ResultAnalysis.cpp(558) : see reference to function template instantiation 'void boost::put,Ref,boost::detail::edge_desc_impl,std::string>(const boost::put_get_helper &,K,const V &)' being compiled 1> with 1> [ 1> Directed=boost::bidirectional_tag, 1> Value=boost::detail::error_property_not_found, 1> Ref=boost::detail::error_property_not_found &, 1> Vertex=void *, 1> Property=boost::propertyboost::edge_weight_t,slScoreValueType, 1> Tag=boost::edge_name_t, 1> Reference=boost::detail::error_property_not_found &, 1> LvaluePropertyMap=boost::adj_list_edge_property_mapboost::edge_weight_t,slScoreValueType,boost::edge_name_t>, 1> K=boost::detail::edge_desc_impl, 1> V=std::string 1> ]