What’s new in Swift 4.1?

This is an Xcode playground that demonstrates the new features introduced in Swift 4.1:

• Synthesized Equatable and Hashable
• Key decoding strategy in Codable
• Conditional conformances
• Recursive constraints on associated types
• Build configuration import testing
• Target environment testing
• flatMap() is now (partly) compactMap()

This is designed to complement my existing article What’s New in Swift 4.1. You might also want to check out What's New in Swift 4.2 and its accompanying playground. 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: This playground requires Swift 4.1, so you should have installed Xcode 9.3 or later. This is available through the Mac App Store or direct from https://developer.apple.com/download.