Down-casting a C object to a Lua object

[Colm Sloan <colmsloan@...>]

In short, does anyone know the Lua equivalent of the C++ code:

DerivedClass d = (DerivedClass)baseClass;

?

But only using Lua code, no C++.

The base class object already has loads of things in it that I need in the derived class. I don't believe I can just use table.copy(t) because I don't think that gets everything. I've been stuck on this for days trying a variety of approaches. Any ideas?

Thanks :)