Swift version: 5.0
Writing multi-platform code has its own challenges, but if you use the
canImport() compiler test then one big challenge is solved for you: you can write one chunk code to run if a specific module is available, and another chunk otherwise.
For example, this code will check for UIKit, AppKit, and all other possibilities so that you can pick whichever color type is best for the current platform:
#if canImport(UIKit) // iOS, tvOS, and watchOS – use UIColor #elseif canImport(AppKit) // macOS – use NSColor #else // all other platforms – use a custom color object #endif
canImport() was available we need to use
#if os(macOS) instead, like this:
#if os(iOS) || os(tvOS) || os(watchOS) // use UIColor #else // use NSColor #endif
canImport() is an improvement because it lets you focus on what functionality you want rather than what operating system. So, if UIKit became available on macOS tomorrow you wouldn’t need to change your code to use it.
Available from iOS 8.0
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.