bool verify_start (framepos_t);
bool verify_start_and_length (framepos_t, framecnt_t&);
bool verify_start_mutable (framepos_t&_start);
- bool verify_length (framecnt_t);
+ bool verify_length (framecnt_t&);
virtual void recompute_at_start () = 0;
virtual void recompute_at_end () = 0;