<span class="special">&lt;</span><span class="identifier">M</span><span class="special">&gt;(</span><span class="identifier">obj</span><span class="special">))</span></code>.
          If the insertion occurs and results in a rehashing of the container, all
          iterators are invalidated. Otherwise, iterators are not affected. References
          are not invalidated. Rehashing occurs only if the new number of elements
          is greater than <a class="link" href="capacity.html" title="object::capaci