Undefined symbols for architecture x86_64

[mpelleau]

When trying to inherit from htd::Hypergraph, I get the following error :

Undefined symbols for architecture x86_64:
  "typeinfo for htd::Hypergraph", referenced from:
      construction vtable for htd::Hypergraph-in-MYHGraph in Main.o
      typeinfo for MYHGraph in Main.o
ld: symbol(s) not found for architecture x86_64

There must be an undefined virtual member function in MYHGraph, but I cannot figure out which function is missing.

Here is the code of my class:

#ifndef MY_HGRAPH_H
#define MY_HGRAPH_H

#include <htd/main.hpp>

class MYHGraph : public htd::Hypergraph {
    public:
        unsigned int rank;
    public:
        MYHGraph() : htd::Hypergraph(htd::createManagementInstance(htd::Id::FIRST)) {}
        MYHGraph(unsigned int rank) : htd::Hypergraph(htd::createManagementInstance(htd::Id::FIRST)), rank(rank) {}
        ~MYHGraph() {}
};

#endif