Merged revisions 22172 via svnmerge from

https://lampsvn.epfl.ch/svn-repos/scala/scala/trunk

........
  r22172 | extempore | 2010-06-05 17:40:48 +0200 (Sat, 05 Jun 2010) | 3 lines

  Patch from Jason Zaugg so singleton types aren't accidentally deprived
of a fourth try at satisfaction. Already reviewed by odersky, so no
review. ........

1 files changed, 55 insertions, 0 deletions

diff --git a/test/files/pos/scala-singleton.scala b/test/files/pos/scala-singleton.scala
new file mode 100644
index 0000000000..08038db93b
--- /dev/null
+++ b/test/files/pos/scala-singleton.scala
@@ -0,0 +1,55 @@
+// A bunch of ridiculous seeming tests until you realize much
+// of this didn't work until the commit which accompanies this.
+object Test {
+  def f1(x: AnyRef with Singleton): AnyRef with Singleton = x
+  def f2[T <: AnyRef with Singleton](x: T): T = x
+
+  val x1: AnyRef with Singleton = "abc"
+  val x2 = "def"
+  final val x3 = "ghi"
+  val x4: String = "jkl"
+
+  // compiles...
+  def narrow1(x: AnyRef): AnyRef with Singleton = x
+
+  // compiles, still doesn't help.
+  def narrow2(x: AnyRef): AnyRef with Singleton = x.asInstanceOf[x.type]
+
+  // fails, wait, what? This fails and narrow1 compiles?
+  def narrow3(x: AnyRef): AnyRef with Singleton = x.asInstanceOf[AnyRef with Singleton]
+
+  // ok
+  def narrow4[T <: AnyRef](x: T): AnyRef with Singleton = x
+
+  object imp {
+    implicit def narrow4[T <: AnyRef](x: T): AnyRef with Singleton = x
+    val x5: String = "mno"
+    def imp1 = f1(x5)
+
+    // f2(x5)   // doesn't work but I think it should
+    def imp2 = f2(narrow4(x5))
+  }
+
+  def main(args: Array[String]): Unit = {
+    // compiles
+    f1(x1)
+    f1(x2)
+    f1(x3)
+    f1(x4)
+
+    f2(x1)
+    // f2(x2)
+    // f2(x3)   // maybe this one should work
+    // f2(x4)
+
+    f1(narrow1(x4))
+    f1(narrow2(x4))
+    f1(narrow3(x4))
+    f1(narrow4(x4))
+    f2(narrow1(x4))
+    f2(narrow2(x4))
+    f2(narrow3(x4))
+    f2(narrow4(x4))
+  }
+}
+