Complex circular dependency

Question

what is the the best practice of solving circular dependency in C++?

I could use the forward declaration, but then I get the pointer to incomplete

Answer 1

You just need to use forward declaration correctly:

1. Put all code in cpp files
2. Put just class declaration in header file
3. In header file:
   1. Use forward declaration if you only use a pointer or a reference.
   2. Otherwise you to include header file. (Do Not add unrequired includes)
4. In cpp file
   1. include all header files you require.

Note: Add include guards.

Its hard to actually do it without the actual declarations. The diagram is nice but does not have enough information. A picture may be worth a thousand words, but a precisely defined language can convey more exact information very compactly (unlike English and its inconsistencies).