[Boost-users] [Graph] Issue with remove_edge function and subgraphs

Subject: [Boost-users] [Graph] Issue with remove_edge function and subgraphs
From: Marcus Fontaine (mfontai5_at_[hidden])
Date: 2010-05-09 16:57:14

According to the online documentation, 
http://www.boost.org/doc/libs/1_38_0/libs/graph/doc/subgraph.html

The remove_edge function when used on a subgraph should,
"Remove the edge (u,v) from the subgraph and from all of the ancestors 
of g in the subgraph tree."

In the example I have here, it just seems to remove the edge between 
vertices 0 and 2 from the ancestor and not the subgraph.

Any advice or explanation would be greatly appreciated.

#include <iostream>
#include <vector>
#include <boost/config.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/subgraph.hpp>

using namespace std;
using namespace boost;

typedef subgraph< adjacency_list<vecS, vecS, undirectedS,
    property<vertex_index_t, int>, property<edge_index_t, int> > > Graph;

int main()
{
    Graph G;
   
    add_edge(0, 1, G);
    add_edge(0, 2, G);
    add_edge(1, 2, G);
    add_edge(2, 3, G);
    add_edge(0, 3, G);

    Graph subG = G.create_subgraph();

    add_vertex(0, subG);
    add_vertex(1, subG);
    add_vertex(2, subG);
    add_vertex(3, subG);
   
    remove_edge(subG.global_to_local(2), subG.global_to_local(0) ,subG);

    graph_traits<Graph>::adjacency_iterator ai;
    graph_traits<Graph>::adjacency_iterator ai_end;

    cout << "Adjacent vertices of 0 in G: ";
    //Should be 1 3, and correctly is so.

    for(tie(ai, ai_end) = adjacent_vertices(0, G); ai != ai_end; ++ai)
    {
        cout << *ai << " ";
    }
    cout << endl;

    cout << "Adjacent vertices of 0 in subG: ";
    //Should be 1 3, but gives 1 2 3.

    for(tie(ai, ai_end) = adjacent_vertices(subG.global_to_local(0), 
subG); ai != ai_end; ++ai)
    {
        cout << subG.local_to_global(*ai) << " ";
    }
    cout << endl;
   
return 0;
}