reading/writing bits from/to a file

Is there a way to read bits for bits from a file and then write bit for bit to a file in c++?

No. All reads and writes operate, at the smallest, on bytes. In fact, by the very definition of a byte, it is the smallest addressible unit of storage.

Every variable, every read and write, etc. operate on integer numbers of bytes.

To elaborate on what Cat said, you have to read it out as a byte (or more), but you can still access the individual bits of the variables you read out of the file by using bit shifting.

Ok, tnx.