A backport of @ViewLoading property wrapper from iOS 16.4

ViewLoader.swift

extension UIViewController {
    /// A property wrapper that loads the view controller’s view before accessing the property.
    /// A backport of `@ViewLoading` property wrapper, available in iOS 16.4.
    /// https://developer.apple.com/documentation/uikit/uiviewcontroller/viewloading
    @propertyWrapper
    struct ViewLoader<Value> {
        static subscript<T: UIViewController>(
            _enclosingInstance instance: T,
            wrapped wrappedKeyPath: ReferenceWritableKeyPath<T, Value>,
            storage storageKeyPath: ReferenceWritableKeyPath<T, Self>
        ) -> Value {
            get {
                instance.loadViewIfNeeded()
                return instance[keyPath: storageKeyPath].storage
            }
            set {
                instance[keyPath: storageKeyPath].storage = newValue
            }
        }

        @available(*, unavailable)
        var wrappedValue: Value {
            get { fatalError() }
            set { fatalError() }
        }

        private var storage: Value!
    }
}