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Last active April 7, 2020 03:07
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`setFailureType` setup with `Just`.
Raw
set_failure_type_setup.swift
import Combine
/// (1) A sample error type we’ll try to promote `Never` to.
enum OurError: Error {
case anError
}
Just(6_174) /// (2) [`Just<Int>.Failure == Never`](https://developer.apple.com/documentation/combine/just/failure).
.mapError { /* `(Never) -> OurError` */ } /// (3) This is…awkward. `mapError` accepts an `(Failure) -> E`
/// closure for some new `Error`-conforming type, `E`. But, this block is never executed since,
/// well, there aren’t any `Never` instances to call it with.
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