Incorrectly supported auto-tupling for case classes

[liufengyun]

Minimized code

case class Foo(a: Int, b: Int)

object Test {
  def foo(x: Foo) = List(x).map(_ + _)
  
  def main(args: Array[String]): Unit = println(foo(Foo(3, 4)))
}

Output

The code compiles and runs.

Expectation

The code should be rejected, as in Scala 2.

[liufengyun]

I don't know if the feature is intentional. But it seems it is not much used and only leads to difficult to understand code.