l#stream_buffer"><code>stream_buffer</code></a>,
      <a href="classes/filtering_stream.html"><code>filtering_stream</code></a>
      and <a href="classes/filtering_streambuf.html"><code>filtering_streambuf</code></a>
      — and of about two thirds of the concrete <a href="quick_reference.html#filters">Filters</a>
      and <a href="quick_reference.html#devices">Devices</a>. Some components,
      however, are implemented in <code>.cpp</code> files; in addition, the <a
        href="classes/regex_filter