class="identifier">runtime_error</span><span class="special">(</span><span class="string">"No target file name specified in settings"</span><span class="special">);</span>

        <span class="identifier">boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">::</span><span class="identifier">time_duration</span> <span class="identifier">write_interval</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</spa