Hi all,
I have started using the boost graph library recently. I want to add vertices
and edges to a graph through an algorithm visitor. I chose the 'discover_vertex'
event and added some code to add a vertex/edge. But the compiler could not
determine the apporpriate the matching add_vertex/add_edge function. I tried
fully specifiying the template arguments with no success. (I am using gcc 3.3.1
on SuSE Linux.)
I tried another alternative which does not work either. I created a pointer to a
graph object which points to my graph insided the 'discover_vertex'. But then I
ended up having a run time error after the vertex is added.
Many thanks,
Abebaw Wubshet
Here is a sample code
/************************************************************************/
#include
#include <iostream>
#include
#include
#include
using namespace boost;
class VertexProperties
{
public:
std::string _name;
VertexProperties () {}
VertexProperties (std::string name) : _name(name) {}
};
//OPTION ONE
class bfs_extend_graph1 : public default_bfs_visitor
{
public:
template
void discover_vertex (Vertex v, Graph& g)
{
std::cout<<"\ndiscover";
Vertex v_new;
//the compile gets confused here !!!!!
v_new = add_vertex(VertexProperties("C"),g);
add_edge(v,v_new,g);
}
};
//OPTION TWO
class bfs_extend_graph2 : public default_bfs_visitor
{
public:
template
void discover_vertex (Vertex v, Graph& g)
{
std::cout<<"\ndiscover";
Vertex v_new;
typedef adjacency_list< vecS, vecS, directedS, VertexProperties>
graph_t;
//a pointer to
shared_ptr ptr_g;
*ptr_g = g; //reference to the actual graph
v_new = add_vertex(VertexProperties("C"),*ptr_g);
add_edge(v,v_new,*ptr_g);
}
};
int main()
{
typedef adjacency_list< vecS, vecS, directedS, VertexProperties> graph_t;
typedef graph_traits::vertex_descriptor Vertex;
typedef graph_traits::vertex_iterator vertex_iterator;
typedef property_map::type VP_map_t;
graph_t g;
Vertex v1,v2;
v1 = add_vertex(VertexProperties("A"),g);
v2 = add_vertex(VertexProperties("B"),g);
add_edge(v1,v2,g);
//get the VP map
VP_map_t VP_map = get(&VertexProperties::_name,g);
bfs_extend_graph1 bfs_e1;
breadth_first_search(g,v1,visitor(bfs_e1));
bfs_extend_graph2 bfs_e2;
breadth_first_search(g,v1,visitor(bfs_e2));
//check if everything is okay
std::pair vp;
std::cout<
