luajit class

https://gist.github.com/gaspard/1087382

https://gist.github.com/marciol/1983296

-- luajit simple_jit.lua
	ffi = require 'ffi'
	simple = ffi.load('simple')
	ffi.cdef[[
	typedef struct Simple Simple;
	Simple *Simple_Simple(int);
	void Simple__gc(Simple *);
	int Simple_id(Simple *);
	]]
	-- wrap into class like behavior
	local mt = {}
	mt.__index = mt
	function mt.id(self, ...)
	return simple.Simple_id(self.super,...)
	end
	function Simple(...)
	local self = {super = simple.Simple_Simple(...)}
	ffi.gc(self.super, simple.Simple__gc)
	return setmetatable(self, mt)
	end
	s = Simple(6)
	print(s:id())