        </p>
<h7><a name="json.ref.boost__json__string.at.overload1.h0"></a>
            <span class="phrase"><a name="json.ref.boost__json__string.at.overload1.synopsis"></a></span><a class="link" href="overload1.html#json.ref.boost__json__string.at.overload1.synopsis">Synopsis</a>
          </h7><pre class="programlisting"><span class="keyword">char</span><span class="special">&amp;</span>
<span class="identifier">at</span><span class="special">(</span>
    <span class="identifier">std</span><span class="