Okay, so..
I supose that this Integer class of yours handles output streams?

x.writeToFile(cout);

It would help if you could post at least the member writeToFile(iostream) so that we can examine it.

Otherwise, I would go using the
library and write an member like

writeToFile(char *name)

maybe something..

bool Integer::writeToFile(char *name){
ofstream out(name);
if(!out){
return false;
}else{
//out to the file
out.close();
return true;
}
}

just a fast doodle..
_________________________
- "It's not my code that's useless
it's you loosers being unable to
apprecitate it because of your
lack of skills!"
/zenon - C++ master Apprentice