outcome_impl"><code class="computeroutput"><span class="identifier">wait_first_outcome_impl</span><span class="special">()</span></code></a>, passing the <code class="computeroutput"><span class="identifier">nqueue</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span></code> rather than <code class="computeroutput"><span class="identifier">queue</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span></code>