I have 3 classes: A, B and C. C is `#include`ed by B, and B is `#includ`ed by A. In class C i have defined a handler for a button, and when the button is pushed, C will `PostMessage` to object A. If i include A in C, i will have a cyclic reference, so what should i do to avoid this cyclic reference?

EDIT: All includes are made in implementation files.