How to exclude unavailable classes from compilation based on the target OS

Using Swift
1

I have a class that's unavailable on iOS, so I annotated it with @available, but the compiler still complains that some symbol is not available on iOS. I even added the annotation to the method itself, but no luck.

How can I fix the error without adding the ugly "#if os(macOS)" around the missing symbol?

@available(iOS, unavailable)
class AboutDelegate {

	// @available(iOS, unavailable)
	func show() {
		var window: UIWindowScene
		//...
		window?.windowingBehaviors?.isMiniaturizable = false // Error: 'windowingBehaviors' is only available in iOS 16.0 or newer
	}
}
2

Per the documentation, windowingBehaviours is only unavailable on macOS: windowingBehaviors | Apple Developer Documentation. It seems like you've got the condition backwards, and should be marking the type unavailable on macOS, not on iOS.

3

I'm actually compiling it for macCatalyst, where the symbol is available, and I've solved it using '#if targetEnvironment(macCatalyst)'. I've wrote "#if os(macOS) for brevity. But that's just an example, I basically want to make some class unavailable on some platform, because it uses symbols not available on that platform.

I have update the example below. It won't compile on iOS.

@available(iOS, unavailable)
class AboutDelegate {

	// @available(iOS, unavailable)
	func show() {
		var window: UIWindowScene
		//...
		if #available(macCatalyst 16.0, *) {
			window.windowingBehaviors?.isMiniaturizable = false // Error: 'windowingBehaviors' is only available in iOS 16.0 or newer
		}
	}
}