id and a data value is available
        or <span class="emphasis"><em>coroutine-function</em></span> has terminated (<span class="emphasis"><em>asymmetric_coroutine&lt;&gt;::pull_type</em></span>
        is invalid; no data value available). Access to the transferred data value
        is given by <span class="emphasis"><em>asymmetric_coroutine&lt;&gt;::pull_type::get()</em></span>.
      </p>
<pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="ident