Untuple using `def` not `val`.

As retronym noted on #897, `val` forces to early.

1 files changed, 8 insertions, 0 deletions

diff --git a/tests/run/function-arity.scala b/tests/run/function-arity.scala
new file mode 100644
index 000000000..6d7e5bce1
--- /dev/null
+++ b/tests/run/function-arity.scala
@@ -0,0 +1,8 @@
+object Test {
+  class T[A] { def foo(f: (=> A) => Int) = f(???) }
+
+  def main(args: Array[String]): Unit = {
+    new T[(Int, Int)].foo((ii) => 0)
+    new T[(Int, Int)].foo((x, y) => 0) // check that this does not run into ???
+  }
+}