Hi all, First of all, I new to the mailing list, so please excuse me for any beginner's mistakes I may make :) I am also new to the Boost Graph Library. I am having some trouble implementing the Boost Graph Library isomorphism algorithm under MSVC++ 2008 Express Edition. Since I am using MSVC++, I cannot use the named parameter method, as specified in the docs. I am not entirely sure, but I think my problem is the vertex invariants that I pass to the algorithm. I am using Boost 1.43. My graph and relevant typedefs look like this: typedef adjacency_list<listS, listS, undirectedS, VertexProperty, EdgeProperty, no_property, listS> UndirectedGraph; typedef graph_traits<UndirectedGraph>::vertex_descriptor VertexDescriptor; I am using bundled properties: struct VertexProperty { string id; int index; }; struct EdgeProperty { string id; int weight; }; Here's my code that tries to call the isomorphism algorithm: bool BoostGraph::Compare(BoostGraph& comparableGraph) { vector<VertexDescriptor> f(GetNoVertices()); property_map<UndirectedGraph, int VertexProperty::*>::type indexMap1 = get(&VertexProperty::index, uGraph); property_map<UndirectedGraph, int VertexProperty::*>::type indexMap2 = get(&VertexProperty::index, comparableGraph.GetGraph()); return isomorphism(uGraph, comparableGraph.GetGraph(), isomorphism_map(make_iterator_property_map(f.begin(), indexMap1, f[0])), ???, ???, vertex_invariant2.max(), indexMap1, indexMap2); } The two '???' are where I need to pass the vertex degree invariants, but I do not know how to construct them. I hope I have supplied sufficient information for you. Thanks in advance!