    an ICU UnicodeString as input.
          </p>
<p>
            Example: match a password, encoded in a UTF-16 UnicodeString:
          </p>
<pre class="programlisting"><span class="comment">//</span>
<span class="comment">// Find out if *password* meets our password requirements,</span>
<span class="comment">// as defined by the regular expression *requirements*.</span>
<span class="comment">//</span>
<span class="keyword">bool</span> <span class="identifier">is_valid_password</span><span class="special"