AudioDevice.swift

func getDeviceID(deviceUID: String) -> AudioObjectID? {
    var deviceUIDCFString = deviceUID as CFString
    var deviceID = kAudioDeviceUnknown
    var propertyAddress = AudioObjectPropertyAddress(mSelector: kAudioHardwarePropertyDeviceForUID, mScope: kAudioObjectPropertyScopeGlobal, mElement: kAudioObjectPropertyElementMaster)

    let dataSize_CFString = UInt32(MemoryLayout<CFString>.stride)
    let dataSize_AudioObjectID = UInt32(MemoryLayout<AudioObjectID>.stride)
  
    // This started giving warnings after upgrading to Swift 5.2
    var translation = AudioValueTranslation(
      mInputData: &deviceUIDCFString, // Warning: "Inout expression creates a temporary pointer, but argument 'mInputData' should be a pointer that outlives the call to 'init(mInputData:mInputDataSize:mOutputData:mOutputDataSize:)'"
      mInputDataSize: dataSize_CFString,
      mOutputData: &deviceID, // Warning: "Inout expression creates a temporary pointer, but argument 'mOutputData' should be a pointer that outlives the call to 'init(mInputData:mInputDataSize:mOutputData:mOutputDataSize:)'"
      mOutputDataSize: dataSize_AudioObjectID
    )
    var specifierSize = UInt32(MemoryLayout<AudioValueTranslation>.stride)
    let result = AudioObjectGetPropertyData(UInt32(kAudioObjectSystemObject), &propertyAddress, 0, nil, &specifierSize, &translation)
    guard result == kAudioHardwareNoError, deviceID != kAudioDeviceUnknown else {
        return nil
    }

    return deviceID
}