iB : iB Com.interface -&gt; iB_class
val make_iB : #iB_class -&gt; iB Com.interface
</pre>
<h4 id="sec32" class="paragraph">Error handling in interfaces:</h4>
<p> Conventionally, methods of
COM interfaces always return a result of type <span class=machine><span class=font-tt>HRESULT</span></span> that says
whether the method succeeded or failed, and in the latter case returns
an error code to its caller.</p><p>When calling an interface method from Caml, if the method returns an
<span class=machine><span cla