I don’t I’m afraid, I use IEC61131-3 (PLC language) for CAN bus comms, not C++
But using these 2 links I’m sure it wouldn’t take much to knock something up…
https://www.arduino.cc/reference/en/language/functions/bits-and-bytes/bitread/
https://www.arduino.cc/reference/en/language/functions/bits-and-bytes/bitwrite/