Re: [Boost-users] [BGL] Problem with color maps for undirected_dfs_visit

From: Jeremy Siek (jsiek_at_[hidden])
Date: 2003-11-13 11:09:02

Hi Tarjei,

You need to initialize the edge index property map (only the vertex index
map is automatically initialized, and then only for VertexList=vecS).

Cheers,
Jeremy

On Thu, 13 Nov 2003, Tarjei Knapstad wrote:

tarjei> I'm trying to implement a DFS visitor and using it with
tarjei> undirected_dfs_visit, but I'm getting a segfault which relates to the
tarjei> edge color map. I've made the following test app for illustration:
tarjei>
tarjei> **************** START CODE ****************
tarjei>
tarjei> #include <vector>
tarjei> #include <boost/graph/adjacency_list.hpp>
tarjei> #include <boost/graph/undirected_dfs.hpp>
tarjei>
tarjei> using namespace boost;
tarjei>
tarjei> struct Types
tarjei> {
tarjei>     typedef adjacency_list<vecS, vecS, undirectedS,
tarjei> 			   property<vertex_color_t, default_color_type>,
tarjei> 			   property<edge_color_t, default_color_type,
tarjei> 				    property<edge_index_t, int> > > GraphType;
tarjei>
tarjei>     typedef std::vector<default_color_type> ColorVec;
tarjei>     typedef color_traits<default_color_type> Color;
tarjei> };
tarjei>
tarjei> int main()
tarjei> {
tarjei>     Types::GraphType g(6);
tarjei>
tarjei>     add_edge(0,1,g);
tarjei>     add_edge(1,2,g);
tarjei>     add_edge(2,3,g);
tarjei>     add_edge(2,4,g);
tarjei>     add_edge(4,5,g);
tarjei>
tarjei>     Types::ColorVec v_colors(num_vertices(g), Types::Color::white());
tarjei>     Types::ColorVec e_colors(num_edges(g), Types::Color::white());
tarjei>
tarjei>     default_dfs_visitor visitor;
tarjei>     undirected_depth_first_visit(g, 0, visitor,
tarjei>                    make_iterator_property_map(&v_colors[0],
tarjei>                                               get(vertex_index, g)),
tarjei>                    make_iterator_property_map(&e_colors[0],
tarjei>                                               get(edge_index, g)));
tarjei> };
tarjei>
tarjei> **************** END CODE ****************
tarjei>
tarjei> The code crashes in undirected_dfs.hpp line 73 the first time it's
tarjei> trying to access a color from the edge color map:
tarjei>
tarjei>     EColorValue uv_color = get(edge_color, *ei);
tarjei>
tarjei> Valgrind turns up a lot of illegal reads/writes to the edge_color_map as
tarjei> well, so I'm guessing that I've screwed up on the colormap creation.
tarjei> Could anyone point out my error? Also, is this an error that could be
tarjei> caught compile time by adding some sort of concept check?
tarjei>
tarjei> Thanks in advance for any help!
tarjei>
tarjei> Regards,
tarjei> --
tarjei> Tarjei
tarjei>
tarjei>
tarjei> _______________________________________________
tarjei> Boost-users mailing list
tarjei> Boost-users_at_[hidden]
tarjei> http://lists.boost.org/mailman/listinfo.cgi/boost-users
tarjei>

----------------------------------------------------------------------
 Jeremy Siek                          http://php.indiana.edu/~jsiek/
 Ph.D. Student, Indiana Univ. B'ton   email: jsiek_at_[hidden]
 C++ Booster (http://www.boost.org)   office phone: [phone]
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