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Yes, I have, for almost 15 years. But I've never dealt with userdata before now.Sorry, Michael, I thought you said you'd be binding code into lua for years.
Your code ends with pushlightuserdata(), then does "return 1". So, it is returning only 1 thing, and that thing is not the userdata you'd created earlier.A userdata is just another Lua object type, like a lightuserdata. So just push it onto the stack and return it. You don't need to use lightuserdatas at all.
I already did what you describe. The CFunction that creates the userdata is named CreadeData(). After creating the C++ object, it returns 2 parameters: the C++ object pointer and the userdata. It ends like this:
lua_pushlightuserdata( L, pData ); luaL_getmetatable( L, "CData_type" ); return 2;The __gc metamethod I registered for this kind of userdata is created and it has the correct pointer for the pData object (which I test using luaL_checkudata()).
BUT... that __gc CFuntion is being called by lua *immediately* after the return from the above code. The lua calling code is like this:
self.ptr, self.pUserData = CreateData()Why is it the __gc being done immediately? This is what I was talking about when I asked about the carbage collector "What defines being "used" by lua?" For some reason, lua believes it is time for this userdata to be deleted. Why?
Basically: lightuserdata: 4 bytes only, no metatable, no notification when GCd userdata: any number of bytes, metatable, notification when GCd Check out the example here: http://www.lua.org/pil/28.1.htmlThe fundamentals of this are covered in the above, and the succeeding chapters which cover __gc (and I also posted a link to), and explained much better than I can. If are comfortable in C, and sit down and spend a few hours reading carefully through those chapters, and write a small example to start with, then build up, you should be OK.
I've read that stuff over and over. That's why I said something just is not clicking.
Michael
Cheers, Sam