[swift-evolution] [Pitch] Introducing the "Unwrap or Die" operator to the standard library

Jaden Geller jaden.geller at gmail.com
Tue Jun 27 12:37:05 CDT 2017

I like this idea, but I like idea of treating `Never` as a bottom type more. This would allow other `Never`-returning functions like `preconditionFailure` to be used as well.

let x = y ?? preconditonFailure("reason")

This also avoids the issue of `!!` needing `file` and `line` arguments.

Jaden Geller

> On Jun 27, 2017, at 10:16 AM, Erica Sadun via swift-evolution <swift-evolution at swift.org> wrote:
> Using an operator to provide feedback on the context of a failed unwrap has become a commonly implemented approach in the Swift developer Community. What are your thoughts about adopting this widely-used operator into the standard library?
> guard !lastItem.isEmpty else { return }
> let lastItem = array.last !! "Array must be non-empty"
> Details here:  https://gist.github.com/erica/423e4b1c63b95c4c90338cdff4939a9b <https://gist.github.com/erica/423e4b1c63b95c4c90338cdff4939a9b>
> Thank you for your thoughtful feedback, -- E
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