Alternate approach to inheritance for Swift structs?

Question

I'm using structs instead of classes to store data in my iOS app because of the obvious advantage of value vs reference types. However, I'm trying to figure out how to architect groups of similar content. User posts may consist of images, text, and/or titles. If I were using classes the approach I would use is having a common Post superclass with different subclasses representing different types of posts. That way I could pass Post data around and cast as needed. However, structs don't allow for inheritance, so how could I architect something similar?

Answer 1

In Swift with struct you can create protocol for common task and also implement default implementation using protocol extension.

protocol Vehicle {     var model: String { get set }     var color: String { get set } }  //Common Implementation using protocol extension extension Vehicle {      static func parseVehicleFields(jsonDict: [String:Any]) -> (String, String) {         let model = jsonDict["model"] as! String         let color = jsonDict["color"] as! String         return (model, color)     } }  struct Car : Vehicle {     var model:String     var color:String     let horsepower: Double     let license_plate: String     init(jsonDict: [String:Any]) {         (model, color) = Car.parseVehicleFields(jsonDict: jsonDict)         horsepower = jsonDict["horsepower"] as! Double         license_plate = jsonDict["license_plate"] as! String     } }  struct Bicycle : Vehicle {     var model:String     var color:String     let chainrings: Int     let sprockets: Int     init(jsonDict: [String:Any]) {         (model, color) = Bicycle.parseVehicleFields(jsonDict: jsonDict)         chainrings = jsonDict["chainrings"] as! Int         sprockets = jsonDict["sprockets"] as! Int     } }