Encode and Decode to Data object in Swift 5.0

DataCodable.swift

protocol DataCodable {
    func toData() -> Data
    init(data: Data)
}

extension Data: DataCodable {
    func toData() -> Data {
        return self
    }
    init(data: Data) {
        self = data
    }
}

extension String: DataCodable {
    func toData() -> Data {
        guard let data = self.data(using: .utf8) else {
            fatalError("Cannot encode using UTF8: \(self)")
        }
        return data
    }
    
    init(data: Data) {
        self = String.init(data: data, encoding: .utf8)!
    }
}

protocol NumericPrimitiveDataCodable: DataCodable {
    associatedtype Primitive
}

extension NumericPrimitiveDataCodable where Self.Primitive == Self {
    func toData() -> Data {
        var value = self
        return Data.init(bytes: &value, count: MemoryLayout<Primitive>.size)
    }
    
    init(data: Data) {
        self = data.withUnsafeBytes { (bfr) -> Primitive in
            return bfr.bindMemory(to: Primitive.self).first!
        }
    }
}

extension Int: NumericPrimitiveDataCodable {
    typealias Primitive = Int
}

extension Double: NumericPrimitiveDataCodable {
    typealias Primitive = Double
}

extension Bool: NumericPrimitiveDataCodable {
    typealias Primitive = Bool
}

do {
  print("Data Codable")
  print(Bool.init(data: true.toData()) == true)
  print(Double.init(data: Double.greatestFiniteMagnitude.toData()) == Double.greatestFiniteMagnitude)
  print(Int.init(data: Int.max.toData()) == Int.max)
}