adding an external property to include index for vertix in graph (boost)

问题

I'm trying to use an associative_property_map to include index for vertices, but I get the following error with the following simple code, what is the problem ?

#include <boost/graph/iteration_macros.hpp>
#include <boost/graph/adjacency_list.hpp>

using namespace std;
using namespace boost;

struct NodeData
{
    int label;
};

struct EdgeData
{
    int age;
};

typedef map<vecS, size_t> IndexMap;
IndexMap mapIndex;
associative_property_map<IndexMap> propmapIndex(mapIndex);

typedef adjacency_list<setS, setS, undirectedS, NodeData, EdgeData> Graph;
typedef Graph::vertex_descriptor NodeID;
typedef Graph::edge_descriptor EdgeID;

int main()
{
    Graph g;

    NodeID n0 = add_vertex(g); g[n0].label = -1;
    NodeID n1 = add_vertex(g); g[n1].label = -1;

    EdgeID edge; bool ok;
    tie(edge, ok) = boost::add_edge(n0, n1, g);
    if (ok) g[edge].age = 10;

    int i=0;
    BGL_FORALL_VERTICES(v, g, Graph)
    {
        put(propmapIndex, v, i++);
    }

    return 0;
}

Errors:

c:\program files\codeblocks\mingw\bin..\lib\gcc\mingw32\4.4.1........\include\boost\property_map\property_map.hpp||In

function 'void boost::put(const boost::put_get_helper&, K, const V&) [with PropertyMap = boost::associative_property_map, std::allocator >

, Reference = unsigned int&, K = void*, V = int]':| C:\Users\memo\Desktop\Debuged\boostGraph\main.cpp|39|instantiated from here| c:\program files\codeblocks\mingw\bin..\lib\gcc\mingw32\4.4.1........\include\boost\property_map\property_map.hpp|361|error: no match for 'operator[]' in '(const boost::associative_property_map, std::allocator > > >&)((const boost::associative_property_map, std::allocator > > >*)(& pa))[k]'| c:\program files\codeblocks\mingw\bin..\lib\gcc\mingw32\4.4.1........\include\boost\property_map\property_map.hpp|498|note: candidates are: typename UniquePairAssociativeContainer::value_type::second_type& boost::associative_property_map::operator[](const typename UniquePairAssociativeContainer::key_type&) const [with UniquePairAssociativeContainer = std::map, std::allocator > >]| ||=== Build finished: 1 errors, 0 warnings ===|

Thanks

回答1:

The vertex descriptor must be specified to IndexMap, so it's map<NodeID, size_t> and not map<vecS, size_t> :

<...>
typedef Graph::vertex_descriptor NodeID;

typedef map<NodeID, size_t> IndexMap;
IndexMap mapIndex;
associative_property_map<IndexMap> propmapIndex(mapIndex);
<...>

// indexing all vertices
int i=0;
BGL_FORALL_VERTICES(v, g, Graph)
{
   put(propmapIndex, v, i++);
}

来源：https://stackoverflow.com/questions/7942457/adding-an-external-property-to-include-index-for-vertix-in-graph-boost