"%-10s %-50s %s".format _
<console>:13: error: missing arguments for method format in trait StringLike;
 follow this method with `_' if you want to treat it as a partially applied function
          "%-10s %-50s %s".format _

import scala.collection.immutable._

scala> ("%-10s %-50s %s": StringLike[_]).format _
res91: Seq[Any] => String = <function1>

scala> val f: Seq[Any] => String = "%-10s %-50s %s".format
f: Seq[Any] => String = <function1>