nullstream is a NOP output stream, used only in the Final configuration for the dout output stream, which is otherwise used for debug information.
dout is often used with std::endl, but using std::endl with nullstream causes compiler errors.
Adding an overload to the << operator resolves that problem.
nullstreamis a NOP output stream, used only in theFinalconfiguration for thedoutoutput stream, which is otherwise used for debug information.doutis often used withstd::endl, but usingstd::endlwithnullstreamcauses compiler errors. Adding an overload to the<<operator resolves that problem.