Selecting enabling for operators in Breeze... Enable

foo.scala

trait Enable[T] {
  def get: T
}

trait EnableLowPriority {
  implicit val eager = new Enable[Eager]{def get = new Eager}
}

object Enable extends EnableLowPriority {
  object Lazy {
    implicit val lzy = new Enable[Lazy]{def get = new Lazy}

  }

}

object Disable {
  object Eager {
// I think I'm cute.
    implicit val `LISTEN: you disabled eager evaluation, but no lazy implicit was found` = new Enable[Eager]{def get = new Eager}
    implicit val `-- Navi` = new Enable[Eager]{def get = new Eager}
  }
}

case class Eager() {
  def dance() = ()
}
case class Lazy() {
  def sleep() = ()
}

object X {
  def foo[R](x: Int, b: Int)(implicit enable: Enable[R]): R = enable.get

  def xxx {
    foo(3,4).dance()
    //foo(3,4).sleep() // error!
  }

  def zzz {
    import Enable.Lazy._
    foo(3,4).sleep()
    //foo(3,4).dance() // error!
  }

  class Baz[R]
  implicit val eagerBaz = new Baz[Eager]

  def bar[R](x: Int, b: Int)(implicit baz: Baz[R], enable: Enable[R]):R = enable.get

  def canBeEagerEvenWithLazy(x: Int, b: Int) = {
    import Enable.Lazy._
    bar(3,4).dance()
  }

  def canDisableEagerEvaluation {
    import Enable.Lazy._
    import Disable.Eager._
    // bar(3,4).dance() // error!
    /* 
foo.scala:58: error: ambiguous implicit values:
 both value LISTEN: you disabled eager evaluation, but no lazy implicit was found in object Eager of type => java.lang.Object with Enable[Eager]
 and value -- Navi in object Eager of type => java.lang.Object with Enable[Eager]
 match expected type Enable[Eager]
    bar(3,4).dance() // error!
    */ 

    ()
  }

}