Re: [Boost-users] [BGL] possible Bug in property handling

28 Aug 2009

      On Fri, 28 Aug 2009, Ralf Goertz wrote:
...
Hi,
I'm new to BGL (and generic programming) so this may well not be a bug
but I don't know how this could be intended. Consider the following
program:
#include <string>
#include <iostream>
#include 
#include 
#include 
using namespace boost;
typedef property VertexProp;
//this crashes
typedef adjacency_list < vecS, vecS, undirectedS,VertexProp, no_property > graph_t;
//this doesn't
//typedef adjacency_list < vecS, listS, undirectedS,VertexProp, no_property > graph_t;
typedef graph_traits < graph_t >::vertex_descriptor vertex_descriptor;
typedef property_map::type id_name_map_t;
typedef graph_traits::vertex_iterator vi_t;
std::pair vi;
int main(){
   graph_t g;
   vertex_descriptor vd;
   id_name_map_t name_map;
   vd=add_vertex(g);
   put(name_map,vd,"foo");
   for (vi=vertices(g); vi.first!=vi.second;++vi.first) {
       std::cout<
It appears that name_map is not initialized.  You need to do something 
like:

id_name_map_t name_map = get(vertex_name, g);

to get the property map before you use it.

-- Jeremiah Willcock