Scala - Dynamically mixin a trait to an instance

DynamicMixIn.scala

  /** This is a marker trait intended to provide independence of FIX version. */
  trait SecurityListLike extends quickfix.Message
  object SecurityListLike {
    implicit def mixin(o: Mixin) = o.o

    def ::(o: quickfix.Message) = new Mixin(o)
    final class Mixin private[SecurityListLike](val o: quickfix.Message) extends SecurityListLike {
      import quickfix.field.MsgType
      require(o.getHeader.getString(MsgType.FIELD) == MsgType.SECURITY_LIST)
    }
  }

Usage:

val message: quickfix.Message = getMessageFromSomewhere
val x: SecurityListLike = message :: SecurityListLike