Merge pull request #3412 from retronym/ticket/2066-2.10-compat

 -Xsource:2.10: lenient treatment of variance in <:<, =:=

2 files changed, 72 insertions, 0 deletions

diff --git a/test/files/pos/t2066-2.10-compat.flags b/test/files/pos/t2066-2.10-compat.flags
new file mode 100644
index 0000000000..94c8056747
--- /dev/null
+++ b/test/files/pos/t2066-2.10-compat.flags
@@ -0,0 +1 @@
+-Xsource:2.10
diff --git a/test/files/pos/t2066-2.10-compat.scala b/test/files/pos/t2066-2.10-compat.scala
new file mode 100644
index 0000000000..fb8103e4ad
--- /dev/null
+++ b/test/files/pos/t2066-2.10-compat.scala
@@ -0,0 +1,71 @@
+import language._
+trait A1 {
+  def f[T[_]] = ()
+}
+
+trait B1 extends A1 {
+  override def f[T[+_]] = ()
+}
+
+trait C1 extends A1 {
+  override def f[T[-_]] = ()
+}
+
+
+trait A2 {
+  def f[T[+_]] = ()
+}
+
+trait B2 extends A2 {
+  override def f[T[_]] = () // okay
+}
+
+trait C2 extends A2 {
+  override def f[T[-_]] = ()
+}
+
+
+trait A3 {
+  def f[T[-_]] = ()
+}
+
+trait B3 extends A3 {
+  override def f[T[_]] = () // okay
+}
+
+trait C3 extends A3 {
+  override def f[T[-_]] = ()
+}
+
+
+trait A4 {
+  def f[T[X[+_]]] = ()
+}
+
+trait B4 extends A4 {
+  override def f[T[X[_]]] = ()
+}
+
+trait A5 {
+  def f[T[X[-_]]] = ()
+}
+
+trait B5 extends A5 {
+  override def f[T[X[_]]] = ()
+}
+
+
+
+trait A6 {
+  def f[T[X[_]]] = ()
+}
+
+trait B6 extends A6 {
+  override def f[T[X[+_]]] = () // okay
+}
+trait C6 extends A6 {
+  override def f[T[X[_]]] = () // okay
+}
+trait D6 extends A6 {
+  override def f[T[X[-_]]] = ()
+}