twitterFutureToScala.scala

import com.twitter.util.{Future => TwFuture}
import scala.concurrent.{Future => ScFuture, promise => ScPromise}
implicit def twFutureToScala[T](twFuture: TwFuture[T]): ScFuture[T] = {
  val prom = ScPromise[T]
  twFuture.onSuccess { res: T =>
    prom.success(res)
  }
  twFuture.onFailure { t: Throwable =>
   prom.failure(t)
  }
  prom.future
}

withTry.scala

import com.twitter.util.{ Future => TwFuture, Try => TwTry }
import scala.util.{Try => ScTry}
import scala.concurrent.{ Future => ScFuture, promise => ScPromise }


implicit def twTryToScalaTry[T](tw : TwTry[T]) : ScTry[T] = {
  ScTry(tw.get)
}

implicit def twFutureToScala[T](twFuture: TwFuture[T]): ScFuture[T] = {
  val prom = ScPromise[T]
  twFuture.respond { t : TwTry[T] =>
    prom.complete(t)
  }
  prom.future
}