pan class="keyword">if</span><span class="special">(</span> <span class="identifier">id_iter</span> <span class="special">!=</span> <span class="identifier">people</span><span class="special">.</span><span class="identifier">by</span><span class="special">&lt;</span><span class="identifier">id</span><span class="special">&gt;().</span><span class="identifier">end</span><span class="special">()</span> <span class="special">)</span>
<span class="special">{</span>
    <span class="identifier">std</span><span c