keyword argument support, removed last traces of std::function<> usage
diff --git a/example/example4.cpp b/example/example4.cpp
index ed9d0da..3293e93 100644
--- a/example/example4.cpp
+++ b/example/example4.cpp
@@ -1,5 +1,5 @@
 /*
-    example/example4.cpp -- Example 4: global constants and functions, enumerations
+    example/example4.cpp -- global constants and functions, enumerations
 
     Copyright (c) 2015 Wenzel Jakob <wenzel@inf.ethz.ch>