1 files changed, 125 insertions, 0 deletions
diff --git a/test/files/run/inferred-type-constructors.scala b/test/files/run/inferred-type-constructors.scala
new file mode 100644
index 0000000000..79a8653f68
--- /dev/null
+++ b/test/files/run/inferred-type-constructors.scala
@@ -0,0 +1,125 @@
+package p {
+  trait TCon[+CC[X]] {
+    def fPublic: CC[Int]                        = ???
+    private[p] def fPackagePrivate: CC[Int]     = ???
+    protected[p] def fPackageProtected: CC[Int] = ???
+  }
+  trait Iterable[+A] extends TCon[Iterable]
+  trait Set[A] extends Iterable[A] with TCon[Set]
+  trait Seq[+A] extends Iterable[A] with TCon[Seq]
+
+  private[p] abstract class AIterable[+A] extends Iterable[A]
+  private[p] abstract class ASeq[+A] extends AIterable[A] with Seq[A]
+  private[p] abstract class ASet[A] extends AIterable[A] with Set[A]
+
+  package m {
+    private[m] abstract class ASeq[A] extends p.ASeq[A] with Seq[A]
+    private[m] abstract class ASet[A] extends p.ASet[A] with Set[A]
+    trait Set[A] extends p.Set[A] with TCon[Set]
+    trait Seq[A] extends p.Seq[A] with TCon[Seq]
+    trait BitSet extends ASet[Int]
+    trait IntSeq extends ASeq[Int]
+  }
+
+  package i {
+    private[i] abstract class ASeq[+A] extends p.ASeq[A] with Seq[A]
+    private[i] abstract class ASet[A] extends p.ASet[A] with Set[A]
+    trait Set[A] extends p.Set[A] with TCon[Set]
+    trait Seq[+A] extends p.Seq[A] with TCon[Seq]
+    trait BitSet extends ASet[Int]
+    trait IntSeq extends ASeq[Int]
+  }
+}
+
+object Test {
+  import scala.reflect.runtime.universe._
+  // Complicated by the absence of usable type constructor type tags.
+  def extract[A, CC[X]](xs: CC[A]): CC[A] = xs
+  def whatis[T: TypeTag](x: T): Unit = {
+    val tpe = typeOf[T]
+    val access = tpe.typeSymbol.asInstanceOf[scala.reflect.internal.HasFlags].accessString.replaceAllLiterally("package ", "")
+    println(f"$access%15s $tpe")
+  }
+
+  trait IntIterable extends p.Iterable[Int]
+  trait IntSet extends p.Set[Int]
+  trait IntSeq extends p.Seq[Int]
+
+  trait MutableIntSet extends p.m.Set[Int]
+  trait MutableIntSeq extends p.m.Seq[Int]
+
+  trait ImmutableIntSet extends p.i.Set[Int]
+  trait ImmutableIntSeq extends p.i.Seq[Int]
+
+  def f1: IntIterable = null
+  def f2: IntSet = null
+  def f3: IntSeq = null
+
+  def g1: MutableIntSet = null
+  def g2: MutableIntSeq = null
+  def g3: p.m.BitSet = null
+
+  def h1: ImmutableIntSeq = null
+  def h2: p.i.BitSet = null
+  def h3: p.i.IntSeq = null
+
+  def main(args: Array[String]): Unit = {
+    whatis(extract(f1))
+    whatis(extract(f2))
+    whatis(extract(f3))
+    whatis(extract(g1))
+    whatis(extract(g2))
+    whatis(extract(g3))
+    whatis(extract(h1))
+    whatis(extract(h2))
+    whatis(extract(h3))
+
+    whatis(extract(if (true) f1 else f2))
+    whatis(extract(if (true) f1 else f3))
+    whatis(extract(if (true) f1 else g1))
+    whatis(extract(if (true) f1 else g2))
+    whatis(extract(if (true) f1 else g3))
+    whatis(extract(if (true) f1 else h1))
+    whatis(extract(if (true) f1 else h2))
+    whatis(extract(if (true) f1 else h3))
+    whatis(extract(if (true) f2 else f3))
+    whatis(extract(if (true) f2 else g1))
+    whatis(extract(if (true) f2 else g2))
+    whatis(extract(if (true) f2 else g3))
+    whatis(extract(if (true) f2 else h1))
+    whatis(extract(if (true) f2 else h2))
+    whatis(extract(if (true) f2 else h3))
+    whatis(extract(if (true) f3 else g1))
+    whatis(extract(if (true) f3 else g2))
+    whatis(extract(if (true) f3 else g3))
+    whatis(extract(if (true) f3 else h1))
+    whatis(extract(if (true) f3 else h2))
+    whatis(extract(if (true) f3 else h3))
+    whatis(extract(if (true) g1 else g2))
+    whatis(extract(if (true) g1 else g3))
+    whatis(extract(if (true) g1 else h1))
+    whatis(extract(if (true) g1 else h2))
+    whatis(extract(if (true) g1 else h3))
+    whatis(extract(if (true) g2 else g3))
+    whatis(extract(if (true) g2 else h1))
+    whatis(extract(if (true) g2 else h2))
+    whatis(extract(if (true) g2 else h3))
+    whatis(extract(if (true) g3 else h1))
+    whatis(extract(if (true) g3 else h2))
+    whatis(extract(if (true) g3 else h3))
+    whatis(extract(if (true) h1 else h2))
+    whatis(extract(if (true) h1 else h3))
+    whatis(extract(if (true) h2 else h3))
+
+    whatis(extract(Nil))
+    whatis(extract(Vector()))
+    whatis(extract(Map[Int,Int]()))
+    whatis(extract(Set[Int]()))
+    whatis(extract(Seq[Int]()))
+    whatis(extract(Array[Int]()))
+    whatis(extract(scala.collection.immutable.BitSet(1)))
+    whatis(extract("abc"))
+    whatis(extract(if (true) Stream(1) else List(1)))
+    whatis(extract(if (true) Seq(1) else Set(1)))
+  }
+}