src/Pure/System/swing_thread.scala

--- a/src/Pure/System/swing_thread.scala	Sat Jun 29 08:45:04 2013 +0200
+++ b/src/Pure/System/swing_thread.scala	Sat Jun 29 12:57:04 2013 +0200
@@ -19,6 +19,8 @@
   def assert() = Predef.assert(SwingUtilities.isEventDispatchThread())
   def require() = Predef.require(SwingUtilities.isEventDispatchThread())
 
+  def required[A](body: => A): A = { require(); body }
+
 
   /* main dispatch queue */