diff --git a/util/collection/TypeFunctions.scala b/util/collection/TypeFunctions.scala
index 8f542fb99..185c72226 100644
--- a/util/collection/TypeFunctions.scala
+++ b/util/collection/TypeFunctions.scala
@@ -15,6 +15,7 @@ trait TypeFunctions
 	final val right = new (Id ~> P1of2[Right, Nothing]#Apply) { def apply[T](t: T) = Right(t) }
 	final val some = new (Id ~> Some) { def apply[T](t: T) = Some(t) }
 	final def idFun[T] = (t: T) => t
+	final def const[A,B](b: B): A=> B = _ => b
 	
 	def nestCon[M[_], N[_], G[_]](f: M ~> N): (M ∙ G)#l ~> (N ∙ G)#l =
 		f.asInstanceOf[(M ∙ G)#l ~> (N ∙ G)#l] // implemented with a cast to avoid extra object+method call.  castless version: