truct</tt>, if needed.
</p>
<p>
The association with a metatable is permanent and cannot be changed
afterwards. Neither the contents of the <tt>metatable</tt> nor the
contents of an <tt>__index</tt> table (if any) may be modified
afterwards. The associated metatable automatically applies to all uses
of this type, no matter how the objects are created or where they
originate from. Note that pre-defined operations on types have
precedence (e.g. declared field names cannot be overriden).
</p>
<p>
All standard 