Can we make adding a parameter with a default value binary compatible?

Language Design
8

For the case classes, you also need to override fromProduct, right? It could look something like this

object Person:
  @synthetic
  def fromProduct(p: Product): Person = p.productArity match
    case 2 =>
      Person(
        p.productElement(0).asInstanceOf[String],
        p.productElement(1).asInstanceOf[String],
      )
    case 3 =>
      Person(
        p.productElement(0).asInstanceOf[String],
        p.productElement(1).asInstanceOf[String],
        p.productElement(2).asInstanceOf[String],
      )
    case 4 =>
      Person(
        p.productElement(0).asInstanceOf[String],
        p.productElement(1).asInstanceOf[String],
        p.productElement(2).asInstanceOf[String],
        p.productElement(3).asInstanceOf[Option[String]],
      )

Shout out to @armanbilge who discovered this