--- a/src/ButtonEvent.h	Thu Mar 14 16:11:08 2019 +0100
+++ b/src/ButtonEvent.h	Thu Mar 14 16:46:16 2019 +0100
@@ -22,6 +22,12 @@
 	int number;
 	bool pressed;
 
+	ButtonEvent() {
+	}
+
+	ButtonEvent(const ButtonEvent& other) : number(other.number), pressed(other.pressed) {
+	}
+
 	ButtonEvent(int number, bool pressed) :
 	number(number), pressed(pressed) {
 	}