json.swift

public enum JSON {

    public typealias D = Dictionary<String, Any>

    public typealias A = Array<Dictionary<String, Any>>

    case dictionary(D)

    case array(A)

    public init(_ dictionary: [String: Any]) {
        self = .dictionary(dictionary)
    }

    public init(_ array: [[String: Any]]) {
        self = .array(array)
    }

    public var dictionary: D? {
        get {
            switch self {
            case .dictionary(let d):
                return d
            default:
                return nil
            }
        }
    }

    public var array: A? {
        get {
            switch self {
            case .array(let a):
                return a
            default:
                return nil
            }
        }
    }
}

Usage is not ideal yet tho. Suggestions?

if let dictionary = json?.dictionary {
} else if let array = json?.array {
}

switch json {
case .array(let array):
case .dictionary(let dictionary):
}

Doesn't look better to me either.