Re: userdata expected, got userdata

[Luiz Henrique de Figueiredo <lhf@...>]

> There are two types of userdata: light and heavy.  I guess
> you're supplying one and the API expects the other.  Sadly,
> it seems impossible to distinguish between the two types on
> the Lua side.

This is true, but it is not an excuse for that poor error message.
The io library gives nice messages even when supplied with userdata:
	bad argument #1 to 'close' (FILE* expected, got userdata)
This is message is produced by luaL_checkudata.
--lhf