$OpenBSD: patch-src_pingus_screens_demo_session_cpp,v 1.1 2019/05/17 19:14:08 cwen Exp $

Add missing header for ports-gcc

Index: src/pingus/screens/demo_session.cpp
--- src/pingus/screens/demo_session.cpp.orig
+++ src/pingus/screens/demo_session.cpp
@@ -17,6 +17,7 @@
 #include "pingus/screens/demo_session.hpp"
 
 #include <algorithm>
+#include <functional>
 #include <iostream>
 
 #include "engine/gui/gui_manager.hpp"
