Implicit resolution falls short when encountering literal type argument aliasing

[soronpo]

At first I encountered this issue in Typelevel Scala:
typelevel/scala#162

After fiddling with LBS and shapeless's Witness, I hit this error again, so it should be handled as an LBS issue.

  import shapeless.Witness
  val three = Witness(3)
  type Three = three.T
  type Something[T] = shapeless.Witness.Aux[T]
  implicitly[shapeless.Witness.Aux[Three]] //works
  implicitly[Something[Three]] //implicit not found

As far as I manage to figure out, you need all three features to hit this error:

• type aliasing
• literal type argument
• implicit resolution

I recommend, if possible, to resolve this before SIP23 (scala/scala#5310) is merged, since it might trip newcomers to the feature.

[hrhino]

I suspect that this might be the same issue, or at least related to, the .deconst/.dealias /&c. issue @retronym brought up over here.

[soronpo]

This unsolvable without a SIP, so SIP23 took care of this. See typelevel/scala#162