We add an `#include` directive for "my_class.h" file in order to have the my_class declaration inserted at this point in the .cpp file, and we include `<iostream>` to pull in the declaration for `std: ...

And in the .cc just #include <header> and define the functions using the normal std type (all declarations inside stdfwd are typedefs into std).. std:: forward declarations can also be used but won't ...