p__buffer_body__value_type.size.when_parsing">When
          Parsing</a>
        </h6>
<p>
          The value of this field will be decremented during parsing to indicate
          the number of remaining free octets in the buffer pointed to by <code class="computeroutput"><span class="identifier">data</span></code>. When it reaches zero, the parser
          will return <a class="link" href="../boost__beast__http__error.html" title="http::error"><code class="computeroutput"><span class="identifier">http</