    <span class="string">"(?(1)"</span>
         <span class="string">"|(?(2)"</span>
            <span class="string">"[[:Cf:][:Cc:][:Z*:]]*"</span>
         <span class="string">")"</span>
         <span class="string">"[[:Sc:]]"</span>
      <span class="string">")"</span><span class="special">;</span>
   <span class="identifier">boost</span><span class="special">::</span><span class="identifier">u32regex</span> <span class="identifier">r</span> <span class="special">=</span> <span class="identifier">boo