Swift tip: Properly deprecating code

As codebases evolve, we inevitably accumulate functions, classes, and APIs that need to be removed or replaced. Use @available(*, deprecated, message: "...") to mark functions as deprecated in your Swift projects:

@available(*, deprecated, message: "This function will be removed in a future release.")
func oldFunction() {
    // legacy code
}

This gives developers, including your future self, a clear heads-up about upcoming changes while keeping code functional during the transition period. The compiler will show warnings but won’t break existing builds.

Swift Deprecation Warning

You can deprecate almost anything in Swift:

Classes, structs, enums, protocols
Functions, methods, initializers
Properties and subscripts
Enum cases and operators

@available(*, deprecated, message: "Use NewUserModel instead")
struct UserModel {
    // ...
}

@available(*, deprecated, message: "Use isEnabled instead")
var isActive: Bool = true

@available(*, deprecated, message: "Use UserRole.admin instead")
enum Status {
    case active
}

Swift’s deprecation system is comprehensive - you can gradually migrate any part of your API while maintaining backward compatibility and providing clear guidance to developers.

Pro tip: Include migration guidance in your message for an even better developer experience!