text_ostream_backend</span><span class="special">,</span>
    <span class="identifier">sinks</span><span class="special">::</span><span class="identifier">bounded_fifo_queue</span><span class="special">&lt;</span>                                                   <a class="co" name="log.detailed.sink_frontends.async.c0" href="sink_frontends.html#log.detailed.sink_frontends.async.c1"><img src="../../../../../../doc/src/images/callouts/1.png" alt="1" border="0"></a>
        <span class="number">100</span><spa