st</span> <span class="identifier">pplx</span><span class="special">::</span><span class="identifier">task_completion_event</span><span class="special">&lt;</span><span class="identifier">utility</span><span class="special">::</span><span class="identifier">size64_t</span><span class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">_get_data_available</span><span class="special">()</span> <span class="keyword">const</span> <span class="special">{</span> <span class="keyword"