Swift 2.2 adds a new build configuration option that makes it easy to combine code code written in versions of Swift into a single file. This might seem unnecessary, but spare a thought to people who write libraries in Swift: do they target Swift 2.2 and hope everyone is using it, or target Swift 2.0 and hope users can upgrade using Xcode?
Using the new build option lets you write two different flavours of Swift, and the correct one will be compiled depending on the version of the Swift compiler.
#if swift(>=2.2) print("Running Swift 2.2 or later") #else print("Running Swift 2.1 or earlier") #endif
Just like the existing
#if os() build option, this adjusts what code is produced by the compiler: if you're using a Swift 2.2 compiler, the second
print() line won't even be seen. This means you can use utter gibberish if you want:
#if swift(>=2.2) print("Running Swift 2.2 or later") #else THIS WILL COMPILE JUST FINE IF YOU'RE USING A SWIFT 2.2 COMPILER BECAUSE THIS BIT IS COMPLETELY IGNORED! #endif
SPONSORED Learn the most up-to-date techniques and strategies for testing new and legacy Swift code in this free practical course for iOS devs who want to become complete Senior iOS Developers.
Link copied to your pasteboard.