[BGL] isomorphism, filtered_graph problems

From: Vladimir Prus (ghost_at_[hidden])
Date: 2001-11-05 04:32:48

I've got several problems with BGL:
1. 'isomorphism' has problems with directed graph. The following does not 
compile:
        [ includes skipped]
        int main()
        {
            adjacency_list<vecS, vecS, directedS> g1, g2;
            isomorphism(g1, g2);
        }
When 'undirectedS' is used, it compiles. Is it my fault, or BGL's?
2. Semantics of num_vertices when applied to filtered_graph is non-intiutive, 
but is not stated explicitly in docs. In truth, it should be better to fix, 
yet I have no idea how this can be easily done -- 
vector<whatever>  v(num_vertices(g)) is an idiomatic usage and changing 
num_vertices semantics for filtered_graph will break it. The only way I see 
to deal with it, it to deprecate vector usage, and create 
resizable-on-subscript container specially for BGL.
3. filtered_graph cannot be made from const graph, since ctor takes non-const 
parameter. This requires making copy of the original graph. Is it the 
recommended way, of just filtered_graph for const underlying graph is not 
implemented?