func main() {
	var L *lua.State
	L = lua.NewState()
	L.OpenLibs()

	rawptr := L.NewUserdata(uintptr(unsafe.Sizeof(Userdata{})))
	var ptr *Userdata
	ptr = (*Userdata)(rawptr)
	ptr.a = 2
	ptr.b = 3

	fmt.Println(ptr)

	rawptr2 := L.ToUserdata(-1)
	ptr2 := (*Userdata)(rawptr2)

	fmt.Println(ptr2)
}
func valueOfProxy(L *lua.State, idx int) (reflect.Value, reflect.Type) {
	vp := (*ValueProxy)(L.ToUserdata(idx))
	return vp.value, vp.t
}