private struct PrivateS: Codable { let value: Int } public struct PublicS: Codable { let value: Int private enum CodingKeys: CodingKey { case value } public init(from decoder: any Decoder) throws { let container: KeyedDecodingContainer = try decoder.container(keyedBy: PublicS.CodingKeys.self) self.value = try container.decode(Int.self, forKey: PublicS.CodingKeys.value) } public func encode(to encoder: any Encoder) throws { var container = encoder.container(keyedBy: PublicS.CodingKeys.self) try container.encode(self.value, forKey: PublicS.CodingKeys.value) } } open class OpenC: Codable { let value: Int }