Sharpen prototypes of implicit methods.

Necessary to make implicit resolution of type-level peano numbers work.
The current commit makes takes the inimal steps to make this happen. We
could also consider sharpening using followAlias every type we constrain
a result, or every time we adapt a type.

1 files changed, 15 insertions, 0 deletions

diff --git a/tests/pos/implicitNums.scala b/tests/pos/implicitNums.scala
new file mode 100644
index 000000000..48c5302f7
--- /dev/null
+++ b/tests/pos/implicitNums.scala
@@ -0,0 +1,15 @@
+object Test {
+
+  trait Number
+  trait Zero extends Number
+  trait Succ[N <: Number](n: N) extends Number
+
+  implicit def succ[N <: Number](implicit n: N): Succ[N] = new Succ[N](n) {}
+  implicit def zero: Zero = new Zero{}
+
+  implicitly[Zero]
+  implicitly[Succ[Zero]]
+  implicitly[Succ[Succ[Zero]]]
+  implicitly[Succ[Succ[Succ[Zero]]]]
+
+}