Chapter 4
Result and Dynamic Callable Types
Section 3
Identity Key Path
Identity Keypath was introduced in the old version of Swift. This feature allows access to an object property, so that a variable can be assigned to a specific property of an object. Swift 5 improved on this, by adding an identity Keypath for the entire object, so a variable can be assigned to the actual object, and it can be modified, even if the properties of the object are constants.