“UnsafePointer”无法转换为“UnsafePointer<_>”

我正在做 TripleDES 加密和解密。出现此错误：

UnsafePointer<UInt8>' is not convertible to 'UnsafePointer<_>

我收到错误的代码是：

        let keyString        = "25d1d4cb0a08403e2acbcbe0"
        let keyData = keyString.data(using: .utf8)!
        let message       = pass
        let data = message.data(using: .utf8)!
        let cryptData    = NSMutableData(length: Int(data.count) + kCCBlockSize3DES)!
        let keyLength              = size_t(kCCKeySize3DES)
        let operation: CCOperation = UInt32(kCCEncrypt)
        let algoritm:  CCAlgorithm = UInt32(kCCAlgorithm3DES)
        let options:   CCOptions   = UInt32(kCCOptionECBMode + kCCOptionPKCS7Padding)

        var numBytesEncrypted :size_t = 0

        let cryptStatus = keyData.withUnsafeBytes { (keyBytes: UnsafePointer<UInt8>) in
            data.withUnsafeBytes { (dataBytes: UnsafePointer<UInt8>) in
                cryptData.withUnsafeMutableBytes { (cryptBytes: UnsafeMutablePointer<UInt8>) in
                    CCCrypt(operation,
                            algoritm,
                            options,
                            keyBytes,
                            keyLength,
                            nil,
                            dataBytes,
                            data.count,
                            cryptBytes,
                            cryptData.count,
                            &numBytesEncrypted)
                }
            }
        }

有人可以帮忙吗？

此错误消息是某种编译器错误的结果：编译器无法编译代码并发出无效且误导性的错误消息。另请参阅https://bugs.swift.org/browse/SR-5931 https://bugs.swift.org/browse/SR-5931

在大多数情况下，您可以：

• 删除类型注释（<UInt8>）揭示真正的原因
• 修复原因
• 再次添加类型注释