[greenn]

If the purpose of defer is to replace the `goto single_exit`, I think the value captures are unnecessary. Any single_exit I've implemented uses the value at the time of function exit, so that I can realloc in the middle of the function.

It would be a shame if this defer was limited to function scope. It would be very useful in nested blocks as well. But, I would still appreciate it.

defer and auto are the only things I would love to see in C.