k" href="overload2.html#json.ref.boost__json__value.as_uint64.overload2.description">Description</a>
          </h7><p>
            If <a class="link" href="../is_int64.html" title="value::is_int64"><code class="computeroutput"><span class="identifier">is_int64</span><span class="special">()</span></code></a>
            is <code class="computeroutput"><span class="keyword">true</span></code>, returns the underlying
            <code class="computeroutput"><span class="identifier">std</span><span class="spe