Overlapping Access

[zaccadams]

Hi,
I'm receiving the build error in Swift 4.2
Overlapping accesses to 'ct', but modification requires exclusive access; consider copying to a local variable

Any suggestions on how to fix. This is on line 140.

let status = ct.withUnsafeMutableBytes { ctRaw in
            dataMutable.withUnsafeMutableBytes { dataRaw in
                keyMutable.withUnsafeMutableBytes{ keyRaw in
                    CCCrypt(operation, algorithm, options, keyRaw, key.count, nil, dataRaw, data.count, ctRaw, ct.count, &num)
                }
            }
        }

[mmswide]

let countCT = ct.count
var num: size_t = 0

    let status = ct.withUnsafeMutableBytes { ctRaw in
        dataMutable.withUnsafeMutableBytes { dataRaw in
            keyMutable.withUnsafeMutableBytes{ keyRaw in
                CCCrypt(operation, algorithm, options, keyRaw, key.count, nil, dataRaw, data.count, ctRaw, countCT, &num)
            }
        }
    }