virtual Rest_req *rest() {return 0;}
virtual Span_req *span() {return 0;}
virtual Beam_req *beam() { return 0 ; }
+ virtual Slur_req *slur() { return 0 ; }
virtual Rhythmic_req*rhythmic() { return 0;}
virtual Real duration() const { return 0.0; }
virtual Request* clone() const =0;
/// a slur
struct Slur_req : Span_req {
virtual Request*clone()const;
+ virtual Slur_req*slur() { return this; }
};