You can still use forward declarations. You can even use them in C++. But you have to be sure to get the signature exactly right (one of my favorite passages fr

You can still use forward declarations. You can even use them in C++. But you have to be sure to get the signature exactly right (one of my favorite passages from “Design & Evolution of C++” involves Stroustrup’s discovery that a lot of programmers were cavalier about their forward declarations, e.g., using “...” as in any declaration where it would be syntactically valid).