Must be a pointer, like this:

In daemon.cpp

Your QList is of Role objects, not of Role pointers. A forward declaration would be sufficient for pointers, but since you are using the entire object, you’ll need to #include “role.h” in your daemon.h file.

Thanks, I was not aware forward declaration worked only for pointers, but it makes sense!

It works for pointers and references (which technically are more or less pointers) and, in both cases, only as long as you need the pointer or reference, but not any of the methods or members of the class.