Make map closure throwable?

[aryaxt]

I think it would be great to make map throwable, and in case of throwing trigger onFailure. The usage could be

protocol Deserializable {
   init(json: [AnyHashable: Any]) throws
}

func fetch<T: Deserializable>(type: T.Type,  path: String) -> Future<T, NEtworkError> {
   return restClient.fetch(path: path).map {
       return try type(json: $0)
   }
}

[yonaskolb]

I think rethrows would be better so every usage site wouldn't have to add try if they don't have a throwing map closure

[arnopoulos]

I like the addition of rethrows that way it won't be a breaking API change either

[aryaxt]

I think my problem might have been something else, looking at the source it looks like it already throws