els the <span class="bold"><strong>Random Access Traversal</strong></span> concept
          if the following expressions are valid and respect the stated semantics.
          In the table below, <code class="computeroutput"><span class="identifier">Distance</span></code>
          is <code class="computeroutput"><span class="identifier">iterator_traits</span><span class="special">&lt;</span><span class="identifier">X</span><span class="special">&gt;::</span><span class="identifier">difference_type</span></