-ADD_ACKNOWLEDGER (Concurrent_hairpin_engraver, hairpin);
-ADD_END_ACKNOWLEDGER (Concurrent_hairpin_engraver, hairpin);
+
+void
+Concurrent_hairpin_engraver::boot ()
+{
+ ADD_ACKNOWLEDGER (Concurrent_hairpin_engraver, hairpin);
+ ADD_END_ACKNOWLEDGER (Concurrent_hairpin_engraver, hairpin);
+}