xity for inplace intersection
        on interval containers">
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              <p>
                <code class="computeroutput"><span class="identifier">T</span><span class="special">&amp;</span>
                <span class="keyword">operator</span> <span class="special">&amp;=</span>
                <span class="special">(</span><span class="identifier">T</span><span class="special">&amp;</span> <span class="identifier">y</span