Eq should extend AnyVal until Phantom types (now Erased terms) are ready

That way, at least you can’t pass null as an instance. The suggestion is not mine, it comes from https://www.reddit.com/r/programming/comments/6elim6/announcing_dotty_012rc1_a_major_step_towards/dimg0nz/.

import dotty.DottyPredef.{eqAny => _, _}
class Foo
object Main {
  def bar[T](value: T)(implicit teq: Eq[T,T]) = value == value
  def main(args: Array[String]): Unit = bar(new Foo)(null) //<--
}

@nicolasstucki , can Eq be made a phantom type, now or later? I’m asking this at the design level for now.

[nicolasstucki]

Phantom types do not exist anymore.

With erased, now we can just do

def bar[T](value: T)(erased implicit teq: Eq[T,T]) = value == value

[odersky]

Hi Paolo, I am scanning the issues and thought maybe you want to take over some of the Eq stuff when you are here. So I am assigning issues as I see them.