Test case for pending #4908

Author: odersky

tests/pending/pos/i4908.scala

@@ -0,0 +1,41 @@
+object Test {
+  trait A
+  trait B
+  trait TestConstructor1 { type F[X <: A]
+    trait FromSet[C[_ <: A with B]]
+
+    trait MSetLike[X <: A with B, This <: MSet[X] with MSetLike[X, This]] {
+      def to[C[X <: A with B] <: MSet[X] with MSetLike[X, C[X]]](fi: FromSet[C]): C[X] = ???
+    }
+    trait MSet[X <: A with B] extends MSetLike[X, MSet[X]]
+    object MSetFactory extends FromSet[MSet]
+  }
+
+  trait TestConstructor4[D] {
+    trait TestConstructor5[E] {
+      trait FromSet[C[_ <: D with E]]
+
+      trait MSetLike[X <: D with E, This <: MSet[X] with MSetLike[X, This]] {
+        def to[C[X <: D with E] <: MSet[X] with MSetLike[X, C[X]]](fi: FromSet[C]): C[X] = ???
+      }
+      trait MSet[X <: D with E] extends MSetLike[X, MSet[X]]
+      object MSetFactory extends FromSet[MSet]
+    }
+  }
+
+  type C = A & B
+  val v1: TestConstructor1 => Unit = { f =>
+    type P[a <: A] = f.F[a]
+
+    type P1[c <: C] = f.MSet[c]
+      (f.MSetFactory: f.FromSet[f.MSet]): Unit
+      (x: P1[C]) => x.to(f.MSetFactory)
+  }
+
+  def f3(f: TestConstructor4[A])(g: f.TestConstructor5[B]): Unit = {
+    type P1[c <: C] = g.MSet[c]
+      (g.MSetFactory: g.FromSet[g.MSet]): Unit
+      (x: P1[C]) => x.to(g.MSetFactory)
+      (x: P1[C]) => x.to[g.MSet](g.MSetFactory)
+  }
+}