`sig
external convert_points : float array -> Gpointer.boxed
= "ml_gnome_canvas_convert_points"
external convert_dash : float -> float array -> Gpointer.boxed
= "ml_gnome_canvas_convert_dash"
external get_points : Gpointer.boxed -> float array
= "ml_gnome_canvas_get_points"
external get_dash : Gpointer.boxed -> float * float array
= "ml_gnome_canvas_get_dash"
val points : float array option Gobject.data_conv
val art_vpath_dash : (float * float array) option Gobject.data_conv
val path_def : GnomeCanvas.PathDef.t option Gobject.data_conv
end`