X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=src%2Flib%2Fevent_history.h;h=4670e7bfe8069b215448d09c62f545af909c7d1c;hb=bcc4e2f7dc4cd5658e199ddacb7202b00ec72cf1;hp=e194f633335f0c3e0850a4db3c101d54aadabfef;hpb=a69d242f3f00207d6ea7320e6723775f4b0dbfb3;p=dcpomatic.git

diff --git a/src/lib/event_history.h b/src/lib/event_history.h
index e194f6333..4670e7bfe 100644
--- a/src/lib/event_history.h
+++ b/src/lib/event_history.h
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2017 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2017-2019 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
@@ -22,6 +22,7 @@
 #define DCPOMATIC_EVENT_HISTORY_H
 
 #include <boost/thread/mutex.hpp>
+#include <boost/optional.hpp>
 #include <list>
 
 class EventHistory
@@ -29,7 +30,7 @@ class EventHistory
 public:
 	explicit EventHistory (int size);
 
-	float rate () const;
+	boost::optional<float> rate () const;
 	void event ();
 
 private: