Hi, I'm new to the boost and the BGL, and as the subject suggests, I'm
trying to get my property bundle-using adjacency list to use a vector
for its WeightMap.
First off, the property bundles in question:
template
struct EdgeProperty
{
EdgeProperty(long double foo = 0):Foo(foo),
Bar(NumberOfBar){}
long double Foo;
vector<long long> Bar;
};
template
struct VertexProperty
{
VertexProperty():Baz(NumberOfBar){}
vector > Baz;
};
The visitor:
struct MyVisitor
: public default_dijkstra_visitor
{
template
void discover_vertex(Vertex u, const Graph& g)
{
cout << "discovered " << u << '\n';
}
template
void tree_edge(Edge e, const Graph& g)
{
cout << "tree edge " << e << '\n';
}
template
void examine_edge(Edge e, const Graph& g)
{
cout << "examining edge " << e << '\n';
}
template
void finish_vertex(Vertex u, const Graph& g)
{
cout << "finishing vertex " << u << endl;
}
};
The graph typedef:
typedef adjacency_list< vecS, vecS, bidirectionalS,
property >,
property > > graph_t;
Adding edges and vertices to the graph works without issue, as does
assigning values to the properties, and navigating it, I was also able
to get my test visitor to work.. using this code:
int _tmain(int argc, _TCHAR* argv[])
{
graph_t mygraph;
//build graph
//...
//set up property accessors
typedef EdgeProperty<1> EdgeProp;
property_map::type edge_foo_t =
get(&EdgeProp::foo, mygraph);
property_map::type edge_bar_t =
get(&EdgeProp::Bar, mygraph);
property_map::type vertex_ind =
get(vertex_index, mygraph);
//dijkstra stuff
size_t numberOfVertices = num_vertices(mygraph);
std::vector<long double> distances(numberOfVertices,
(numeric_limits<long double>::max)());
vector predecessors(numberOfVertices);
MyVisitor vis;
dijkstra_shortest_paths(mygraph, *vi,
weight_map(edge_foo_t)
.weight_map2(edge_bar_t)
.distance_map(
make_iterator_property_map(distances.begin(), vertex_ind)
)
.predecessor_map(
make_iterator_property_map(predecessors.begin(), vertex_ind)
)
.visitor(vis)
);
return 0;
}
However when I switch edge_bar_t and edge_foo_t within the
weight_map/weight_map2 parentheses, I get this error (Visual Studio
2005) 'bool std::less<_Ty>::operator ()(const _Ty &,const _Ty &) const'
: cannot convert parameter 1 from 'std::vector<_Ty>' to 'const D &'
Of course that's normal because it's a vector. I figure I'm supposed to
use make_iterator_property_map and somehow point it to
&EdgeProp::Bar::begin() (or &EdgeProp::Bar::rbegin()) with a
property_map<...> as I did with the others...but what I've tried so far
hasn't worked.
Any ideas?
Thanks very much and best wishes,
Geoff
