Originally posted by: skkim

how can we print out nodeid?

I tried 

cout<< getNodeId() << endl;

or

getenv().out()<< getNodeId() << endl;

Neither of them is working. 

You can either use the _id field of class IloCplex::MIPCallbackI::NodeId directly

std::cout << getNodeId()._id;

or define this operator (a more elegant but also more intrusive solution)

inline std::ostream &
operator<<(std::ostream &s, IloCplex::MIPCallbackI::NodeId const &id) {
   return s << id._id;
}

With this operator you can then just do

std::cout << getNodeId();

Originally posted by: skkim

Thank you. It works...