What’s new in Swift 5.1?

This is an Xcode playground that demonstrates the new features introduced 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
• Matching optional enums against non-optionals
• Ordered collection diffing
• Creating uninitialized arrays

This is designed to complement my existing article What’s New in Swift 5.1. You might also want to read What’s New in Swift 5.0 and What’s New in Swift 4.2. Alternatively, I have a whole website dedicated to tracking what’s new in Swift – you should check it out at https://www.whatsnewinswift.com.

If you hit problems or have questions, you’re welcome to tweet me @twostraws or email paul@hackingwithswift.com.

Note: Until a version of Xcode ships with Swift 5.1, you should download the latest Swift trunk development snapshot and activate it inside your current Xcode version.