Move more code
diff --git a/src/hb-ot-layout.hh b/src/hb-ot-layout.hh
index f5ffe31..64b3d74 100644
--- a/src/hb-ot-layout.hh
+++ b/src/hb-ot-layout.hh
@@ -112,32 +112,16 @@
 			       hb_buffer_t  *buffer);
 
 
-struct hb_ot_layout_lookup_accelerator_t
-{
-  template <typename TLookup>
-  inline void init (const TLookup &lookup)
-  {
-    digest.init ();
-    lookup.add_coverage (&digest);
-  }
-  inline void fini (void) {}
-
-  inline bool may_have (hb_codepoint_t g) const
-  { return digest.may_have (g); }
-
-  private:
-  hb_set_digest_t digest;
-};
-
 namespace OT {
   struct hb_ot_apply_context_t;
   struct SubstLookup;
+  struct hb_ot_layout_lookup_accelerator_t;
 }
 
 HB_INTERNAL void
 hb_ot_layout_substitute_lookup (OT::hb_ot_apply_context_t *c,
 				const OT::SubstLookup &lookup,
-				const hb_ot_layout_lookup_accelerator_t &accel);
+				const OT::hb_ot_layout_lookup_accelerator_t &accel);
 
 
 /* Should be called before all the position_lookup's are done. */