1 files changed, 7 insertions, 7 deletions
diff --git a/src/library/dao/trackdao.h b/src/library/dao/trackdao.h
index 19c2e09661..9df042b977 100644
--- a/src/library/dao/trackdao.h
+++ b/src/library/dao/trackdao.h
@@ -75,21 +75,21 @@ class TrackDAO : public QObject, public virtual DAO, public virtual GlobalTrackC
     void trackClean(TrackId trackId);
 
     // Multiple tracks
-    void tracksAdded(QSet<TrackId> trackIds);
-    void tracksChanged(QSet<TrackId> trackIds);
-    void tracksRemoved(QSet<TrackId> trackIds);
+    void tracksAdded(const QSet<TrackId>& trackIds);
+    void tracksChanged(const QSet<TrackId>& trackIds);
+    void tracksRemoved(const QSet<TrackId>& trackIds);
 
-    void progressVerifyTracksOutside(QString path);
-    void progressCoverArt(QString file);
+    void progressVerifyTracksOutside(const QString& path);
+    void progressCoverArt(const QString& file);
     void forceModelUpdate();
 
   public slots:
     // Slots to inform the TrackDAO about changes that
     // have been applied directly to the database.
     void slotDatabaseTracksChanged(
-            QSet<TrackId> changedTrackIds);
+            const QSet<TrackId>& changedTrackIds);
     void slotDatabaseTracksRelocated(
-            QList<RelocatedTrack> relocatedTracks);
+            const QList<RelocatedTrack>& relocatedTracks);
 
   private:
     friend class LibraryScanner;