identifier">r</span> <span class="special">=</span> <span class="identifier">x3</span><span class="special">::</span><span class="identifier">phrase_parse</span><span class="special">(</span><span class="identifier">first</span><span class="special">,</span> <span class="identifier">last</span><span class="special">,</span>

        <span class="comment">//  Begin grammar</span>
        <span class="special">(</span>
            <span class="identifier">double_</span><span class="special">[</span><span clas