A: It is implementation dependent. Verify with your compiler's documentation. For instance, assume you wish to do binary I/O using std::cin & std::cout.
Unluckily there is no standard method to cause std::cout, std::cin and/or std::cerr to be opened in binary mode. Closing the streams and trying to reopen them in binary mode may have undesirable or unexpected results.
On systems where this makes a difference, the implementation may provide a way to make them binary streams; however you would have to verify the implementation specifics to determine out.