ave to conform to a changed interface (see
            <a class="link" href="../lex/abstracts/lexer_semantic_actions.html" title="Lexer Semantic Actions">Lexer Semantic
            Actions</a> for details).
          </li>
<li class="listitem">
            Added placeholder symbols usable from the inside of lexer semantic actions
            while using Phoenix: <code class="computeroutput"><span class="identifier">lex</span><span class="special">::</span><span class="identifier">_start</span></code>,
     