X-Git-Url: https://git.carlh.net/gitweb/?a=blobdiff_plain;f=src%2Flib%2Fevent_history.h;h=a98447f4246f58aa37d11514a59406e59a3af326;hb=5a5f6d3ac42668017141469fd0e5cd14e3bebe88;hp=f723591fbd19bd81c0fa052e997a59c88195a22c;hpb=b19987ae5342602977b265ba9167ec09e433367c;p=dcpomatic.git

diff --git a/src/lib/event_history.h b/src/lib/event_history.h
index f723591fb..a98447f42 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) 2017-2021 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
@@ -18,18 +18,22 @@
 
 */
 
+
 #ifndef DCPOMATIC_EVENT_HISTORY_H
 #define DCPOMATIC_EVENT_HISTORY_H
 
+
 #include <boost/thread/mutex.hpp>
+#include <boost/optional.hpp>
 #include <list>
 
+
 class EventHistory
 {
 public:
-	EventHistory (int size);
+	explicit EventHistory (int size);
 
-	float rate () const;
+	boost::optional<float> rate () const;
 	void event ();
 
 private:
@@ -43,4 +47,5 @@ private:
 	int const _size;
 };
 
+
 #endif