Common Attributes in Swift

// @available for API availability
@available(iOS 15.0, macOS 12.0, *)
func newFeature() {
    print("This requires iOS 15+")
}

@available(*, deprecated, message: "Use newMethod instead")
func oldMethod() {
    print("This method is deprecated")
}

// @objc for Objective-C interop
@objc class MyClass: NSObject {
    @objc dynamic var name: String = ""

    @objc func doSomething() {
        print("Callable from Objective-C")
    }
}

// @discardableResult
@discardableResult
func configure() -> Bool {
    // Setup code
    return true
}

configure()  // No warning about unused result

// @escaping for closures
func performAsync(completion: @escaping () -> Void) {
    DispatchQueue.main.async {
        completion()
    }
}