Yet another BGL's Betweenness centrality issue - c++

Question

Drawing on this reply, I've tried to implement the Betweenness centrality as follows:
typedef struct vpr_
{
int id;
} VProp;
typedef boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, VProp, EProp> graph_t;
boost::shared_array_property_map<double, boost::property_map<graph_t, int>::const_type> centrality_map(num_vertices(g), get(VProp::id, g));
But the following error was returned.
In file included from /usr/local/include/boost/graph/adjacency_list.hpp:246:0,
from /usr/local/include/boost/graph/random.hpp:23,
from ../../src/graph/Graph.h:25,
from Graph.cpp:23:
/usr/local/include/boost/graph/detail/adjacency_list.hpp: In instantiation of ‘struct boost::adj_list_any_vertex_pa::bind_<int, boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, vpr_, epr_>, vpr_>’:
/usr/local/include/boost/graph/detail/adjacency_list.hpp:2568:12: required from ‘struct boost::detail::adj_list_choose_vertex_pa<int, boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, vpr_, epr_>, vpr_>’
/usr/local/include/boost/graph/detail/adjacency_list.hpp:2705:12: required from ‘struct boost::adj_list_vertex_property_selector::bind_<boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, vpr_, epr_>, vpr_, int>’
/usr/local/include/boost/graph/properties.hpp:217:12: required from ‘struct boost::detail::vertex_property_map<boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, vpr_, epr_>, int>’
/usr/local/include/boost/graph/properties.hpp:228:10: required from ‘struct boost::property_map<boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, vpr_, epr_>, int>’
Graph.cpp:374:76: required from here
/usr/local/include/boost/graph/detail/adjacency_list.hpp:2498:29: error: forming reference to void
/usr/local/include/boost/graph/detail/adjacency_list.hpp:2499:35: error: forming reference to void
/usr/local/include/boost/graph/detail/adjacency_list.hpp:2502:47: error: forming reference to void
/usr/local/include/boost/graph/detail/adjacency_list.hpp:2504:53: error: forming reference to void
Graph.cpp: In member function ‘void Graph::getBetweennes()’:
Graph.cpp:374:88: error: template argument 2 is invalid
Graph.cpp:375:17: error: invalid type in declaration before ‘(’ token
In file included from ../../src/graph/graph_t.h:33:0,
from ../../src/graph/Graph.h:26,
from Graph.cpp:23:
../../src/graph/VProp.h:38:6: error: invalid use of non-static data member ‘vpr_::id’
Graph.cpp:375:46: error: from this location
Graph.cpp:375:52: error: expression list treated as compound expression in initializer [-fpermissive]
EDIT
#include <boost/graph/iteration_macros.hpp>
#include <boost/random/mersenne_twister.hpp>
#include <boost/graph/random.hpp>
typedef struct vpr_
{
int id;
} VProp;
typedef struct epr_
{
int id;
} EProp;
typedef boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, VProp, EProp> graph_t;
int main(void) {
graph_t g;
boost::shared_array_property_map<double, boost::property_map<graph_t, VProp::*>::const_type> centrality_map(num_vertices(g), get(&VProp::id, g));
}
The code has been compiled with g++ -L/usr/local/lib -lboost_graph gtest.cpp, and the returned error is:
gtest.cpp: In function ‘int main()’:
gtest.cpp:18:81: error: template argument 2 is invalid
gtest.cpp:18:94: error: template argument 2 is invalid
gtest.cpp:18:110: error: invalid type in declaration before ‘(’ token
gtest.cpp:18:146: error: expression list treated as compound expression in initializer [-fpermissive]
gtest.cpp:18:146: error: cannot convert ‘boost::adj_list_any_vertex_pa::bind_<int vpr_::*, boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, vpr_, epr_>, vpr_>::type {aka boost::adj_list_vertex_property_map<boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, vpr_, epr_>, int, int&, int vpr_::*>}’ to ‘int’ in initialization
How could I fix this? Thanks in advance

Answer 1

Jackb, this BGL algorithm like many others in BGL requires a "vertex index property map" -- a one-to-one mapping between set of graph vertices and integer numbers within interval [0,num_vertices(g)).
Now, your structures EProp and VProp cannot be used as substitutes for vertex_index property maps, and it is what causes the compilation errors.
If you can use boost::adjacency_list<boost::vecS, ...> as your graph type, then vertex_index mapping will come for free (as internal property of the graph). Then you will be able to call centrality algorithms the way it is called in your referenced thread: centrality_map(num_vertices(g), get(boost::vertex_index, g));.
If for some reasons you cannot use boost::vecS, you have to organize the mapping yourself. For setS and listS it is discussed here How to use boost::graph algorithms with listS, setS as vertex/edge containers? and references thereof.
See related discussions on Property Map here What is a property map in BOOST? and specifically on vertex_index map here: Dijkstra Shortest Path with VertexList = ListS in boost graph