 to be returned by the initiating function,
</span><span class="c1"></span>  <span class="c1">// the co_await of which will yield a result_type
</span><span class="c1"></span>  <span class="k">using</span> <span class="n">return_type</span> <span class="o">=</span> <span class="k">typename</span> <span class="n">_base</span><span class="o">::</span><span class="n">return_type</span><span class="p">;</span>

  <span class="c1">// Get what would be the completion handler for the async_result
</span><span clas