Add test

Author: odersky

tests/neg/i7060.scala

@@ -0,0 +1,19 @@
+object PostConditions1 {
+
+  import PostConditions.{ensure, res, Box}
+
+  val v = List(1, 2, 4).sum.ensure(Box(10) => res == 10) // error: not a legal formal parameter
+  println(v)
+}
+
+object PostConditions {
+
+  class Box[T](val t: T)
+
+  def res[T] given (b: Box[T]): T = b.t
+
+  def (e: T) ensure[T](cond: given Box[T] => Boolean): T = {
+    if (cond given Box(e)) e
+    else throw new AssertionError("condition not fulfilled")
+  }
+}