+void
+Source::add_playlist (Playlist* pl)
+{
+ _playlists.insert (pl);
+}
+
+void
+Source::remove_playlist (Playlist* pl)
+{
+ std::set<Playlist*>::iterator x;
+
+ if ((x = _playlists.find (pl)) != _playlists.end()) {
+ _playlists.erase (x);
+ }
+}
+
+uint32_t
+Source::used () const
+{
+ return _playlists.size();
+}