e>Not_found</code> if <code class="code">c</code> does not occur in <code class="code">s</code> before position <code class="code">i+1</code>.</li>
</ul></li>
</ul>
</div>

<pre id="VALrindex_from_opt">val rindex_from_opt : bytes -&gt; int -&gt; char -&gt; int option</pre><div class="info ">
<div class="info-desc">
<p><code class="code">rindex_from_opt&nbsp;s&nbsp;i&nbsp;c</code> returns the index of the last occurrence
    of byte <code class="code">c</code> in <code class="code">s</code> before position <