Swift has always been smart enough to handle switch/case pattern matching between optionals and non-optionals for strings and integers, but before Swift 5.1 that wasn’t extended to enums.
Well, in Swift 5.1 we can now use switch/case pattern matching to match optional enums with non-optionals, like this:
enum BuildStatus {
case starting
case inProgress
case complete
}
let status: BuildStatus? = .inProgress
switch status {
case .inProgress:
print("Build is starting…")
case .complete:
print("Build is complete!")
default:
print("Some other build status")
}Swift is able to compare the optional enum directly with the non-optional cases, so that code will print “Build is starting…”
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Other changes in Swift 5.1…
- Improvements to synthesized memberwise initializers
- Implicit returns from single-expression functions
- Universal Self
- Opaque return types
- Static and class subscripts
- Warnings for ambiguous none cases
- Ordered collection diffing
- Creating uninitialized arrays
Download all Swift 5.1 changes as a playground Link to Swift 5.1 changes
