Index: libcfa/prelude/builtins.c
===================================================================
--- libcfa/prelude/builtins.c	(revision f5cb7c269226704242a4ae0da454d766be24093c)
+++ libcfa/prelude/builtins.c	(revision 85855b0f02c6f17de398969fbe7ab4810d76737a)
@@ -178,4 +178,10 @@
 } // distribution
 
+struct quasi_void {};
+static inline void ?{}(quasi_void &) {}
+static inline void ?{}(quasi_void &, quasi_void) {}
+static inline void ^?{}(quasi_void &) {}
+static inline quasi_void ?=?(quasi_void &, quasi_void & _src) { return _src; }
+
 // Local Variables: //
 // mode: c //