swift generic.swift

Posted 2021-05-19

struct Book<T> {
  let id: Int
  let related: T?
}

extension Book {
  
   init?(json: [String: Any]) {
    
    if let jornalDictionary = json["jornal"] as? [String: Any], let jornal = Jornal(json: questionDictionary) {
      related = jornal // Error: Cannot assign value of type `Jornal` to type `_?`
    } else {
      related = nil
    }

  }
  
}