Implicits for Either? Nasty of helpful?

gistfile1.scala

object Either {
  implicit def aToLeft[A, B](value: A): Left[A, B] = Left(value)
  implicit def bToRight[A, B](value: B): Right[A, B] = Right(value)
}

import Either._

case class User(id: Either[Long, String])

User(123L)
// res0: User = User(Left(123))

User("123")
// res1: User = User(Right(123))