fier">id</span><span class="special">&gt;::</span><span class="identifier">const_iterator</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">find</span><span class="special">(</span><span class="identifier">user_id</span><span class="special">);</span>
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