LateInitialized Property Wrapper

LateInitialized.swift

@propertyWrapper
struct LateInitialized<T> {
    var storage: T? = nil
    
    var wrappedValue: T {
        get {
            guard let value = storage else {
                fatalError("value has not been set!")
            }
            return value
        }
        set {
            storage = newValue
        }
    }
}