From 1247b6f785d22fd66242df649ef92c5d35cbcbf3 Mon Sep 17 00:00:00 2001
From: liu fengyun <liu@fengy.me>
Date: Mon, 11 Sep 2017 17:59:08 +0200
Subject: [PATCH] add test case for #2239

---
 tests/pos/i2239.scala | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
 create mode 100644 tests/pos/i2239.scala

diff --git a/tests/pos/i2239.scala b/tests/pos/i2239.scala
new file mode 100644
index 000000000000..4eb64d8b3508
--- /dev/null
+++ b/tests/pos/i2239.scala
@@ -0,0 +1,14 @@
+trait Rule[-In, +A] extends (In => A) {
+  def flatMap[In2 <: In, B](fa2ruleb: A => Rule[In2, Seq[B]]): Rule[In, Seq[B]] = ???
+  def map[B](fa2b: A => B): Rule[In, B] = ???
+
+  def ~++[In2, B >: A](next: => Rule[In2, Seq[B]]) = for (a <- this; b <- next) yield a :: b.toList
+  // def ~++[In2, B >: A](next: => Rule[In2, Seq[B]]): Rule[In, Seq[B]] = for (a <- this; b <- next) yield a :: b.toList
+}
+
+class SeqRule {
+  type S
+  type A
+  def * : Rule[S, List[A]] = ???
+  def +(rule: Rule[S, A]) : Rule[S, Seq[A]] = rule ~++ *
+}