C++ many classes referencing each other

Question

I have a series of classes that need to reference each other like this

class A
{
     vector<B *> B_list;
     vector<C *> C_list;
     ... 
};

for each class. I'm currently using one header file for all.cpp files which looks like this:

class B; class C; class A {...}; class B {...}; class C{...};

I'm wondering if there's a way to have one header per class.

Edit for clarity: I'm starting a project and need three pretty large, detailed, and distinct classes that each interact with each other frequently.

I have created minimal code for each class like this class A { C *c_item; B *b_item; } A; class A { C *c_item; B *b_item; } A; that includes the other classes and each header hass a blank.cpp file. Compiling it results in undefined type errors because no class can be defined without the others.

So, I added in forward declarations to each class header like class C; class B; class C; class B; which results in 'C' does not name a type errors and in my original code, I got a few class already defined errors when I was messing around with forward declarations.

The only way I could get everything working was to use one header file like I said above. I then tried using three separate headers that all included one header with forward declarations class A; class B; class C; class A; class B; class C; and that didn't fix anything.

Edit 2, found the issue: I was writing class A {...} A; and now I'm writing class A {...}; with the forward declarations at the top of each file and it's working, but I'm not sure why that difference made it work.

Answer 1

Yes, you can have one header per class, for the class A header, type #include "classB.h" at the top and for the class B header type "include "classC.h" in that and then you should have 3 separate header files and the code you wrote should be fine.