2"></a>
          <span class="phrase"><a name="beast.ref.boost__beast__http__parser.content_length.remarks"></a></span><a class="link" href="content_length.html#beast.ref.boost__beast__http__parser.content_length.remarks">Remarks</a>
        </h6>
<p>
          The return value is undefined unless <a class="link" href="../boost__beast__http__basic_parser/is_header_done.html" title="http::basic_parser::is_header_done"><code class="computeroutput"><span class="identifier">http</span><span class="special">::<