On Nov 15, 2005, at 12:53 PM, Daniel Mitchell wrote:
I work with very large implicit graphs that use out-of-core storage for
properties, including the vertex color property,
Very cool.
but the following bit of
code in dijkstra_shortest_paths_no_init (boost-1.33.0) seems to
preclude the
use of a custom color map.
std::vector color(num_vertices(g));
default_color_type c = white_color;
breadth_first_visit(g, s, Q, bfs_vis,
make_iterator_property_map(&color[0], index_map, c));
What is the rationale for the above code, and how should I work around
it?
Well, I'd say that's a bug in dijkstra_shortest_paths_no_init, which
should have a ColorMap template parameter. The best way to fix this
would be to add a ColorMap parameter at the end, e.g., to turn
dijkstra_shortest_paths_no_init into:
template
inline void
dijkstra_shortest_paths_no_init
(const VertexListGraph& g,
typename graph_traits<VertexListGraph>::vertex_descriptor s,
PredecessorMap predecessor, DistanceMap distance, WeightMap weight,
IndexMap index_map,
Compare compare, Combine combine, DistZero zero,
DijkstraVisitor vis, ColorMap color);
Then just pass that color map through to the underlying
breadth_first_search. For backward compatibility reasons, one would
provide a helper function with the old signature that creates that
iterator_property_map and forwards to the new, more-parameterized
version.
If you happen to make this change, I was greatly appreciate it if you
would send it to the list so that we can incorporate it in future
versions of the library. If we're quick, we can even get it into the
upcoming 1.33.1 bug-fix release.
Doug
