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by dullgiulio 3275 days ago
Deferred functions don't return anything. You can modify the values that are returned by the parent function, and those will be returned as the deferred function modified them.
2 comments

Yep, and one cannot simulate that with local variables. In Go "return v" copies v into the return location before calling the deferred code. If that location is not named, the deferred function has no way to change it, see https://play.golang.org/p/Opg4XI08P7
I got it. That's a neat example. Do you have to define that deferred function inside the caller, in order to reference the name? Or can you factor out deferred functions to be used by various callers and pass in the return names for them to modify?
You can pass a pointer to the named return values to a function defined outside, like in https://play.golang.org/p/5jBKcUCj8C .
Ah, okay, thanks. I get it better now. Sort of like decorators in purpose, then.