Merge pull request #4303 from milessabin/topic/backport-7753

Backported fix for SI-7753 to 2.10.x.

1 files changed, 29 insertions, 0 deletions

diff --git a/test/files/pos/t8223.scala b/test/files/pos/t8223.scala
new file mode 100644
index 0000000000..52d6b0098e
--- /dev/null
+++ b/test/files/pos/t8223.scala
@@ -0,0 +1,29 @@
+package p {
+  class ViewEnv[AIn] {
+    type A = AIn
+    class SubView { def has(x: A): Boolean = ??? }
+    def get: SubView = new SubView
+  }
+
+  trait HasA { type A }
+  trait Indexable[R] extends HasA
+  class ArrayTC[AIn] extends Indexable[Array[AIn]] { type A = AIn }
+}
+
+package object p {
+  implicit def arrayTypeClass[A] : ArrayTC[A] = new ArrayTC[A]
+  object intArrayTC extends ArrayTC[Int]
+
+  type EnvAlias[W <: HasA] = ViewEnv[W#A]
+  type SubAlias[W <: HasA] = ViewEnv[W#A]#SubView
+
+  def f0[R](xs: R)(implicit tc: Indexable[R]): ViewEnv[tc.A]#SubView     = new ViewEnv[tc.A]() get
+  def f1[R](xs: R)(implicit tc: Indexable[R]): EnvAlias[tc.type]#SubView = new ViewEnv[tc.A]() get
+  def f2[R](xs: R)(implicit tc: Indexable[R]): SubAlias[tc.type]         = new ViewEnv[tc.A]() get
+
+  def g0 = f0(Array(1)) has 2                   // ok
+  def g1 = f1(Array(1)) has 2                   // ok
+  def g2 = f2(Array(1)) has 2                   // "found: Int(2), required: tc.A"
+  def g3 = f2(Array(1))(new ArrayTC[Int]) has 2 // "found: Int(2), required: tc.A"
+  def g4 = f2(Array(1))(intArrayTC) has 2       // ok
+}