In C++, can you refer to a class before it is defined?

Question

In my code, I create a class which has a member that is an object of another class. However, that class is defined after the first one. So, for example, I would have in the definition of class Alpha a member which is of class Beta, but I define class Beta after class Alpha. Currently, I am getting an error "syntax error: identifier Alpha".

Answer 1

You might put a forward declaration on top of Alpha:

class Beta;

https://gieseanw.wordpress.com/2018/02/25/the-joys-of-forward-declarations-results-from-the-real-world

But you should also think about avoiding circular dependencies, if that is the actual case here. Not possible to tell without seeing your code.

https://pvigier.github.io/2018/02/09/dependency-graph.html