Up to now, I've always been running everything from single files. But now, I've started to learn classes and this approach is no longer practical.

Essentially, I'm trying to create an instance of a certain class from within a different file (e.g. test file with a main() function).

How would I do this so my class is recognized from the test file?
(something like a package in PL/SQL or a package in Java...but how to do in C++??)

Thanks!!