+std::istream& operator>>(std::istream& o, ARDOUR::AutoConnectOption& sf);
+std::istream& operator>>(std::istream& o, ARDOUR::EditMode& sf);
+std::istream& operator>>(std::istream& o, ARDOUR::MonitorModel& sf);
+std::istream& operator>>(std::istream& o, ARDOUR::RemoteModel& sf);
+std::istream& operator>>(std::istream& o, ARDOUR::SoloModel& sf);
+std::istream& operator>>(std::istream& o, ARDOUR::LayerModel& sf);
+std::istream& operator>>(std::istream& o, ARDOUR::CrossfadeModel& sf);
+std::istream& operator>>(std::istream& o, ARDOUR::SlaveSource& sf);
+std::istream& operator>>(std::istream& o, ARDOUR::ShuttleBehaviour& sf);
+std::istream& operator>>(std::istream& o, ARDOUR::ShuttleUnits& sf);
+std::istream& operator>>(std::istream& o, ARDOUR::SmpteFormat& sf);
+std::istream& operator>>(std::istream& o, ARDOUR::DenormalModel& sf);
+
+using ARDOUR::nframes_t;
+
+static inline nframes_t
+session_frame_to_track_frame (nframes_t session_frame, double speed)