.eof()
looks at the end of file flag. The flag is set after you run over the end of the file. This is not desirable.
A great blog post on how this works and best practice can be found here.
Basically, use
std::string line;
while(getline(file, line)) { ... }
or
while (file >> some_data) { ... }
as it will notice errors and the end of the file at the correct time and act accordingly.