Not if to_upper is virtual. Then you work through a base pointer or reference.
I can't implement 'string::to_upper()' unless I inherit. (And then it would be 'my_string::to_upper()'.)
It won't work without string. It's completely dependent on it, in fact.I can distribute 'to_upper(string)', by itself, in any form.
to_upper(string) must as well. How can you build it without string?The 'string::to_upper()' must be a part of the declaration of 'string' and probably must be packaged with the rest of the methods.