Next code are both Ok, why we need the new function future? It seems future just has following signture, anything I miss E.g. for some situation we can just use one of them?
def future[T](body: =>T)(implicit execctx: ExecutionContext): Future[T] = Future[T](body)
scala.concurrent.future was deprecated in 2.11.0 and will be removed in a future version of Scala, so the answer is you don't need both, and don't use