sigc::signal<void, bool> signal_power;
sigc::signal<void, bool> signal_halt;
sigc::signal<void, const DetectedLocomotive &> signal_locomotive_detected;
sigc::signal<void, bool> signal_power;
sigc::signal<void, bool> signal_halt;
sigc::signal<void, const DetectedLocomotive &> signal_locomotive_detected;
virtual void set_sensor(unsigned, bool) = 0;
virtual bool get_sensor(unsigned) const = 0;
virtual void set_sensor(unsigned, bool) = 0;
virtual bool get_sensor(unsigned) const = 0;