Swift 4 Decodable - Dictionary with enum as key

Question

My data structure has an enum as a key, I would expect the below to decode automatically. Is this a bug or some configuration issue?

import Foundation

enum          


        

Answer 1

Following from Imanou's answer, and going super generic. This will convert any RawRepresentable enum keyed dictionary. No further code required in the Decodable items.

public extension KeyedDecodingContainer
{
    func decode(_ type: [K:V].Type, forKey key: Key) throws -> [K:V]
        where K: RawRepresentable, K: Decodable, K.RawValue == R,
              V: Decodable,
              R: Decodable, R: Hashable
    {
        let rawDictionary = try self.decode([R: V].self, forKey: key)
        var dictionary = [K: V]()

        for (key, value) in rawDictionary {
            guard let enumKey = K(rawValue: key) else {
                throw DecodingError.dataCorrupted(DecodingError.Context(codingPath: codingPath,
                     debugDescription: "Could not parse json key \(key) to a \(K.self) enum"))
            }
            
            dictionary[enumKey] = value
        }

        return dictionary
    }
}