keyword">class</span> <a class="link" href="../../concepts/Body.html" title="Body"><span class="emphasis"><em>Body</em></span></a><span class="special">,</span>
    <span class="keyword">class</span> <a class="link" href="../../concepts/Fields.html" title="Fields"><span class="emphasis"><em>Fields</em></span></a><span class="special">&gt;</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span>
<span class="identifier">write</span><span class="special">