swift-protocols

This question already has an answer here: EXC_BAD_ACCESS Using IBInspectable 1 answer I want to have a default property of UIImageView , which would be isFlipped . I am able to do it by subclassing UIImageView and adding one property isFlipped . But I want to user protocol and extensions for this , but it is crashing after sometime. Below is my code. How can I use it in right way? Thanks import Foundation import UIKit protocol FlipImage { var isFlipped: Bool { get set } } extension UIImageView:FlipImage{ var isFlipped: Bool { get { return self.isFlipped } set { self.isFlipped = newValue } } }

The following code doesn't compile: enum Occupation: String { case designer = "Designer" case engineer = "Engineer" } public struct SteveJobs: Codable { let name: String let occupation: Occupation } On the other hand, it should compile since the Occupation is represented as a String which is Codable . Why can't I use enum with raw value in Codable structs? In particular, why automatic conformance isn't working in such a case. Automatic Codable synthesis is “opt-in,” i.e. you have to declare the conformance explicitly: enum Occupation: String, Codable { // <--- HERE case designer = "Designer"

Been having lots and lots of trouble with Swift protocols in combination with arrays, but I couldn't even reproduce my whole problem before things started to break in playground. Here's a minimal example. I have two protocols and a class Bus which declares conformance to one of the protocols. In addition, an empty extension of Bus declares conformance to the other protocol: import Foundation @objc protocol Displayable { var name: String {get} } @objc protocol Utterable { var utterance: String {get} } class Bus : Displayable { var name = "a bus"; var utterance = "this is a bus"} extension Bus :

I have 2 protocols, Filters and Parameters , both of which extend Encodable protocol Filters: Encodable { var page: Int { get } } protocol Parameters: Encodable { var type: String { get } var filters: Filters { get } } I create structs conforming to these protocols, thusly… struct BankAccountFilters: Filters { var page: Int var isWithdrawal: Bool } struct BankAccountParamters: Parameters { let type: String = "Bank" var filters: Filters } let baf = BankAccountFilters(page: 1, isWithdrawal: true) let bap = BankAccountParamters(filters: baf) Which fails because… error: type 'BankAccountParamters'

I've read through the relevant sections of Apple's Swift iBook (Type Casting & Protocols) but I can seem to find a way to specify that an object is an instance of a particular class that conforms to a specific protocol. As an example in tableView(_: , cellForRowAt: ) I would like to cast the cell returned by tableView.dequeueReusableCell(withIdentifier: reuseID, for: indexPath) as being a subclass of UITableViewCell that conforms to the RLMEntityCapableCell protocol (Just specifies that conformers have a variable called item that is an instance of Object , or one of its subclasses). This route