div class="abstract">
                        <p>&ldquo;If no characters match the range, then don&rsquo;t consume any characters
(and unconsume the U+0023 NUMBER SIGN character and, if appropriate,
the X character). This is a parse error; nothing is returned.&rdquo;</p>

                      </div>
                      <div class="declaration">
                        <h4>Declaration</h4>
                        <div class="language">
                          <p class="aside-title">Swift</p>
           