ead-only access to a sequence of characters.
    <LI><A STYLE="font-weight:normal" HREF="../concepts/sink.html">Sink:</A> Provides write-only access to a sequence of characters.
    <LI><A STYLE="font-weight:normal" HREF="../concepts/bidirectional_device.html">BidirectionalDevice:</A> Provides access to two separate sequences of characters, one for reading and the other for writing.
    <LI><A STYLE="font-weight:normal" HREF="../concepts/seekable_device.html">SeekableDevice:</A> Provides read-write access t