Fix #2009: Fix placeholder params logic for lambdas (#2019)

* Fix #2009: Fix placeholder params logic for lambdas

Logic was missing placeholders in rhs of lambdas.

* Add comment

* Fix typo

1 files changed, 9 insertions, 0 deletions

diff --git a/tests/pos/i2009.scala b/tests/pos/i2009.scala
new file mode 100644
index 000000000..e2cf47203
--- /dev/null
+++ b/tests/pos/i2009.scala
@@ -0,0 +1,9 @@
+object Test {
+
+  trait Gen[T] {
+    def map[U](f: T => U): Gen[U] = ???
+  }
+
+  def f[T](implicit g: Gen[T]): Gen[() => T] =
+    g map ( () => _ )
+}