/h7><p>
            If <a class="link" href="../is_array.html" title="value::is_array"><code class="computeroutput"><span class="identifier">is_array</span><span class="special">()</span></code></a>
            is <code class="computeroutput"><span class="keyword">true</span></code>, returns a reference
            to the underlying <a class="link" href="../../boost__json__array.html" title="array"><code class="computeroutput"><span class="identifier">array</span></code></a>, otherwise throws an exception.
