basefield
i.setf(b, ios::basefield);
if (!(stream.flags() & ios::basefield)) {
else if ((stream.flags() & ios::basefield) == ios::hex)
else if ((stream.flags() & ios::basefield) == ios::oct)
if ((stream.flags() & ios::basefield) == ios::oct) { // Octal
else if ((stream.flags() & ios::basefield) == ios::hex) { // Hex