Test to close scala/bug#5075.

milessabin · Jun 1, 2018 · 94e2285 · 94e2285
1 parent f16eacc
commit 94e2285
Showing 1 changed file with 27 additions and 0 deletions.
diff --git a/test/files/pos/t5075.scala b/test/files/pos/t5075.scala
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+// Derived 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] }
+
+trait HKT[D[_]]
+trait HKTBounded[C[X] <: Traversable[X], D[_]]
+trait Cov[+T]
+
+class Test {
+    // exercise type constructor inference in different ways
+    implicit def m[D[_]](t: HKT[D]): Int = 1
+    def mCov[D[_]](t: Cov[HKT[D]]): Any = ???
+    def mBounded[C[X] <: Traversable[X], D[_]](t: Cov[HKTBounded[C, D]]): Any = ???
+
+    val param: HKT[PartialApply1Of2[Tuple2, Int]#Apply] = ???
+    m[PartialApply1Of2[Tuple2, Int]#Apply](param): Int // Already compiled
+    m(param) // Compiles now
+    param: Int // Compiles now
+
+    val paramCov: Cov[HKT[PartialApply1Of2[Tuple2, Int]#Apply]] = ???
+    mCov[PartialApply1Of2[Tuple2, Int]#Apply](paramCov)
+    mCov(paramCov)
+
+    val paramBounded: Cov[HKTBounded[Traversable, PartialApply1Of2[Tuple2, Int]#Apply]] = ???
+    mBounded[Traversable, PartialApply1Of2[Tuple2, Int]#Apply](paramBounded)
+    mBounded(paramBounded)
+}