ate</span><span class="special">(</span><span class="identifier">ast</span><span class="special">,</span>
        <span class="identifier">first</span><span class="special">,</span>
        <span class="identifier">last</span><span class="special">)</span></code>
        annotates the AST with information required by <code class="computeroutput"><span class="identifier">x3</span><span class="special">::</span><span class="identifier">position_tagged</span></code>.
      </p>
<h5>
<a name="spirit_x3.tutorial