is absolutely necessary for beams, since they have to adjust the
length of stems of notes they encompass.
*/
-class Spanner : public Grob
+class Spanner : public Preinit<Spanner>, public Grob
{
Drul_array<Item *> spanned_drul_;
vsize break_index_;
void set_bound (Direction d, Grob *);
Item *get_bound (Direction d) const;
+ void pre_init ();
Spanner (SCM);
Spanner (Spanner const &);
bool is_broken () const;