nion</tt></td><td class="convop">copy (identical type)</td><td class="convout"><tt>struct</tt>/<tt>union</tt></td></tr>
</table>
<p>
Bitfields or <tt>enum</tt> types are treated like their underlying
type.
</p>
<p>
Conversions not listed above will raise an error. E.g. it's not
possible to convert a pointer to a complex number or vice versa.
</p>

<h3 id="convert_vararg">Conversions for vararg C&nbsp;function arguments</h3>
<p>
The following default conversion rules apply when passing Lua objects
to the var