1 files changed, 51 insertions, 0 deletions
diff --git a/tests/pos/tcpoly_infer_ticket1864.scala b/tests/pos/tcpoly_infer_ticket1864.scala
new file mode 100644
index 000000000..4b7c7a223
--- /dev/null
+++ b/tests/pos/tcpoly_infer_ticket1864.scala
@@ -0,0 +1,51 @@
+import scala.collection.mutable.{Buffer, ArrayBuffer}
+
+class RichBuffer[T, B[U] <: Buffer[U]](buffer: Buffer[T]) {
+  def mymap[S](f: T => S)(implicit rv: B[S]): B[S] = {
+    buffer.foreach{ e =>
+      rv += f(e)
+    }
+    rv
+  }
+}
+
+object App {
+  def mymap2[T, B[U] <: Buffer[U], S](buffer: B[T], f: T => S)(implicit rv: B[S]): B[S] = {
+    buffer.foreach{ e =>
+      rv += f(e)
+    }
+    rv
+  }
+
+  def mymap3[T, B <: Buffer[T], S](buffer: B, f: T => T)(implicit rv: B): B = {
+    buffer.foreach{ e =>
+      rv += f(e)
+    }
+    rv
+  }
+
+  def mymap4[T, B[U] <: Buffer[U], S](buffer: B[T])(f: T => S) (implicit rv: B[S]): B[S] = {
+    buffer.foreach{ e =>
+      rv += f(e)
+    }
+    rv
+  }
+
+
+  def main(args: Array[String]): Unit = {
+    implicit def richBuffer[T, B[U] <: Buffer[U]](buffer: B[T]): RichBuffer[T, B] =
+      new RichBuffer[T, B](buffer)
+
+    implicit val rv: scala.collection.mutable.ArrayBuffer[Int] = new ArrayBuffer[Int]
+    val buf = new ArrayBuffer[Int]
+    (1 to 5).foreach(buf += _)
+    buf.mymap(x => x*x)
+    richBuffer(buf).mymap[Int](x => x*x)
+    richBuffer[Int, ArrayBuffer](buf).mymap[Int](x => x*x)
+    mymap2(buf, (x: Int) => x*x)
+    mymap2[Int, ArrayBuffer, Int](buf, (x: Int) => x*x)
+    // mymap3(buf, x => x*x)                                     // compiler error
+    mymap3(buf, (x: Int) => x*x)
+    mymap4(buf)(x => x*x)
+  }
+}