JSONType.swift

@dynamicMemberLookup
protocol JSONType { 
    subscript(dynamicMember member: String) -> JSONType? { get set }
}
extension JSONType {
    subscript(dynamicMember member: String) -> JSONType? {
        get { nil }
        set { }
    }
    subscript<T>(type: T.Type) -> T? {
        get { self as? T }
        set {
            if self is T, let newValue = newValue as? Self {
                self = newValue
            }
        }
    }
}
extension Dictionary: JSONType where Key == String {
    subscript(dynamicMember member: String) -> JSONType? {
        get { self[member] as? JSONType }
        set {
            if let newValue = newValue as? Value {
                self[member] = newValue
            }
        }
    }
}
extension Optional: JSONType where Wrapped == JSONType {
    subscript(dynamicMember member: String) -> JSONType? {
        get { 
            self?[dynamicMember: member]
        }
        set {
            self?[dynamicMember: member] = newValue
        }
    }
}

extension String: JSONType { }
extension Int: JSONType { }
extension Double: JSONType { }
extension Bool: JSONType { }
extension Array: JSONType { }




var dict: [String: Any] = [
    "random": [
        "id": 34538560,
        "ns": 3,
        "title": "User talk:59.188.42.121"
    ]
]

dict.random.title
dict.random.title[String.self]?.append("sssss")
dict.random.title
dict.random.title[Int.self] = 45
dict.random.title