Index: /trunk/FACT++/src/EventImp.h
===================================================================
--- /trunk/FACT++/src/EventImp.h	(revision 10370)
+++ /trunk/FACT++/src/EventImp.h	(revision 10371)
@@ -28,10 +28,10 @@
 
     // Function handling
-    EventImp &AssignFunction(boost::function<int(const EventImp &)> func) { fFunction = func; return *this; }
+    EventImp &AssignFunction(const boost::function<int(const EventImp &)> &func) { fFunction = func; return *this; }
     bool HasFunc() const { return !fFunction.empty(); }
     int ExecFunc() const { return HasFunc() ? fFunction(*this) : -1; }
 
     // Configuration helper
-    EventImp &operator()(boost::function<int(const EventImp &)> func) { return AssignFunction(func); }
+    EventImp &operator()(const boost::function<int(const EventImp &)> &func) { return AssignFunction(func); }
     EventImp &operator()(const std::string str) { SetDescription(str); return *this; }
     EventImp &operator()(const char *str) { SetDescription(str); return *this; }