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To-be-closed variables must contain objects with '__toclose' metamethods (or nil). Functions were removed for several reasons: * Functions interact badly with sandboxes. If a sandbox raises an error to interrupt a script, a to-be-closed function still can hijack control and continue running arbitrary sandboxed code. * Functions interact badly with coroutines. If a coroutine yields and is never resumed again, its to-be-closed functions will never run. To-be-closed objects, on the other hand, will still be closed, provided they have appropriate finalizers. * If you really need a function, it is easy to create a dummy object to run that function in its '__toclose' metamethod. This comit also adds closing of variables in case of panic.