From 1591c14e504246d2cb49b1f7f3e00f6d986f6a06 Mon Sep 17 00:00:00 2001 From: Iulian Dragos Date: Tue, 17 Jan 2012 15:23:02 +0100 Subject: Make specialization pick up opportunities when the specialized method has additional (non-specialized) type parameters. This fix comes from Stefan's desire to specialize HLists (see corresponding test). review by @prokopec --- test/files/specialized/spec-hlists.scala | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 test/files/specialized/spec-hlists.scala (limited to 'test/files/specialized/spec-hlists.scala') diff --git a/test/files/specialized/spec-hlists.scala b/test/files/specialized/spec-hlists.scala new file mode 100644 index 0000000000..8c4ac8f610 --- /dev/null +++ b/test/files/specialized/spec-hlists.scala @@ -0,0 +1,29 @@ +/** Test contributed by Stefan Zeiger showing that HLists can be + * specialized. + */ + +sealed trait HList { + type Self <: HList + + type |: [E] = HCons[E, Self] + + final def |: [@specialized E](elem: E): |: [E] = new HCons[E, Self](elem, this.asInstanceOf[Self]) + + def m[@specialized E, T <: AnyRef](x: E): T = null.asInstanceOf[T] +} + +final class HCons[@specialized H, T <: HList](val head: H, val tail: T) extends HList { + type Self = HCons[H, T] +} + +final object HNil extends HList { + type Self = HNil.type +} + +object Test extends App { + val l1 = new HCons(42, "foo" |: HNil) + println(l1.getClass) + + val l2 = 42 |: "abc" |: HNil + println(l2.getClass) +} -- cgit v1.2.3