static void evaluate_empty (Grob*);
DECLARE_SCHEME_CALLBACK (width_callback, (SCM smob, SCM axis));
DECLARE_SCHEME_CALLBACK (get_bar_size, (SCM ));
static void evaluate_empty (Grob*);
DECLARE_SCHEME_CALLBACK (width_callback, (SCM smob, SCM axis));
DECLARE_SCHEME_CALLBACK (get_bar_size, (SCM ));