+/** @return position of the first thing on the playlist, if it's not empty */
+optional<DCPTime>
+Playlist::start () const
+{
+ if (_content.empty ()) {
+ return optional<DCPTime> ();
+ }
+
+ DCPTime start = DCPTime::max ();
+ BOOST_FOREACH (shared_ptr<Content> i, _content) {
+ start = min (start, i->position ());
+ }
+
+ return start;
+}
+