t;</span><span class=identifier>nil_t</span><span class=special>&gt;
        </span><span class=identifier>no_match</span><span class=special>() </span><span class=keyword>const
        </span><span class=special>{ </span><span class=keyword>
            return </span><span class=identifier>match</span><span class=special>&lt;</span><span class=identifier>nil_t</span><span class=special>&gt;(); </span><span class=special>
        }

        </span><span class=keyword>const </span><span class=identifier>matc