an><br>
&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;to_channel&nbsp;:<br>
&nbsp;&nbsp;&nbsp;&nbsp;<span class="constructor">Pervasives</span>.out_channel&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;<span class="keywordsign">'</span>a&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;<span class="constructor">Marshal</span>.extern_flags&nbsp;list&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;unit<br>
&nbsp;&nbsp;<span class="keyword">external</span>&nbsp;to_string&nbsp;:&nbsp;<span class="keywor