     /// Symmetric decryption.
     case Decrypt
     
-    private func cValue() -> CCOperation {
+    private var cValue: CCOperation {
         switch (self) {
             case .Encrypt:
                 return CCOperation(kCCEncrypt)

        
        let ccOptions = Option.CCValue(options)
        
        self.init(operation: operation.cValue(), algorithm: algorithm.toRaw(), options: ccOptions, key: key, initialisationVector: initialisationVector, returningDataForMemory: &location)
    }
    
    /// Init with data for Objective-C. Marked as internal for Swift as there is a Swift specific init.

private extension RDHAlgorithm
{
    /// @returns the block size for the algorithm
    private var blockSize: Int {
        return self.toRaw().blockSize
    }
    
    /// @returns the memory size needed to create the CryptorRef for the algorithm
    private var contextSize: Int {
        return self.toRaw().contextSize
    }
}

