Then hopefully 0 means identical, 1 means different files, and anything else is an error.

It does seem to return exitcode 128 if I give it an unknown cmdline argument, and exitcode 1 if there are changed files.

@Some programmer dude: true, I am using delimiter() opportunistically with stringstream and ostringstream which havetellp(). If I can define the template as to only accept these types, that would be preferable.

@463035818_is_not_an_ai: if basic_ostream supports manipulators defined as callable objects, then that is probably an option.

The context here is building a string with comma-delimited stats, some of which may not be available (like PID, GID, etc). I'm trying to avoid having a comma as the first character in the stream. And boost::join(list, ", ") is more cumbersome, I'd prefer to output directly to the stream instead of a temporary list which I then join at the end.