he node this is part of the element e1, the node x is part of the element e2 and both elements are included in the containers s1 and s2, then after the swap-operation e1 is in s2 at the position of e2 and e2 is in s1 at the position of e1. If one element is not in a container, then after the swap-operation the other element is not in a container. Iterators to e1 and e2 related to those nodes are invalidated.</p>
<p><span class="bold"><strong>Complexity</strong></span>: Constant</p>
<p><span class="bold"><st