Test to close scala/bug#5075.

milessabin · milessabin · commit 705f194bbc92 · 2018-03-03T12:30:32.000Z
diff --git a/test/files/pos/t5075.scala b/test/files/pos/t5075.scala
@@ -0,0 +1,37 @@
+object BugReport {
+    //Copied from Scalaz - http://scalaz.googlecode.com/svn/continuous/latest/browse.sxr/scalaz/PartialApplys.scala.html
+    trait PartialApply1Of2[T[_, _], A] {
+      type Apply[B] = T[A, B]
+
+      type Flip[B] = T[B, A]
+    }
+
+    trait TypeWithHigherKindParam[D[_]]
+    implicit def function[D[_]](t: TypeWithHigherKindParam[D]) = 1
+    val param: TypeWithHigherKindParam[PartialApply1Of2[Tuple2, Int]#Apply] = null
+
+    function[PartialApply1Of2[Tuple2, Int]#Apply](param): Int //Compiles
+    function(param) //Does not compile
+    param: Int //Does not compile
+
+    //More complex variations of the same problem:
+    //trait Exp[+T]
+
+    /*trait TypeWithHigherKindParam[D[_]]
+    def function[D[_]](t: Exp[TypeWithHigherKindParam[D]]) = null
+    val param: Exp[TypeWithHigherKindParam[PartialApply1Of2[Tuple2, Int]#Apply]] = null
+    function[PartialApply1Of2[Tuple2, Int]#Apply](param)
+    function(param)*/
+
+    /*
+    trait TypeWithHigherKindParam[C[X] <: Traversable[X], D[_]]
+
+    def function[C[X], D[_]](t: Exp[TypeWithHigherKindParam[C,D]]) = null
+    val param: Exp[TypeWithHigherKindParam[Traversable, PartialApply1Of2[Tuple2, Int]#Apply]] = null
+    function[Traversable, PartialApply1Of2[Tuple2, Int]#Apply](param)
+    function(param)
+    */
+}
+
+// vim: set ts=4 sw=4 et:
+
