Add missing file to build.

[libsub.git] / src / font_size.h

diff --git a/src/font_size.h b/src/font_size.h
index 0b4b357457641a2cafb05e602978add08a12bd5a..6f4f8a52ace530b18c361436bf8029af3fe0a2c1 100644 (file)
--- a/src/font_size.h
+++ b/src/font_size.h
@@ -20,6 +20,8 @@
 #ifndef LIBSUB_FONT_SIZE_H
 #define LIBSUB_FONT_SIZE_H
 
+#include <boost/optional.hpp>
+
 namespace sub {
 
 /** @class FontSize