diff -Nrup a/include/internal/infrastructure/event/delegate.h b/include/internal/infrastructure/event/delegate.h
--- a/include/internal/infrastructure/event/delegate.h	2018-10-25 07:56:10.000000000 -0600
+++ b/include/internal/infrastructure/event/delegate.h	2019-09-23 20:01:51.045172921 -0600
@@ -13,6 +13,7 @@
 
 
 #include <functional>
+#include <string>