An idea for TCP closures and rust's effect system

[SkiFire13]

@tema2

The destructors should be run before returning (setting the value, then jumping).

What if a function 1 passes a closure (that does a non-local return) to a function 2, which in turn passes it to a function 3. Now the moment the function is run and the return is triggered it needs to run the destructors of function 3's local variables, then function 2's local variables and the function 1's local variables. How can it know it?

@tema2

what if we do it like that:

(
   *const fn(*mut ResumeTy), /*a callback for setting where to place resume arg*/
   (
   *mut YieldTy /*place for a value*/,
   *mut *const fn() /*next resume address*/
   ) //`yield`info
)

I'm not entirely sure that would work (it probably does? not considering the destructors), but anyway this looks a bit too overhead for the average case where callee and closure can just be inlined.