gex/icu.hpp&gt; provides a series of thin wrappers
            around these algorithms, called <code class="computeroutput"><span class="identifier">u32regex_match</span></code>,
            <code class="computeroutput"><span class="identifier">u32regex_search</span></code>, and
            <code class="computeroutput"><span class="identifier">u32regex_replace</span></code>. These
            wrappers use iterator-adapters internally to make external UTF-8 or UTF-16
            data look as though it's real