A problem with include

You have cyclic dependencies. You can use forward declaration to remove them. However, with forward dependencies you are allowed only class pointers in the header file.

//Class1.h
class Class3; // Forward declaration.
class Class1
{
   ...
   
private:
   
   Class3* mClass3;
};

<br />

//Class2.h
#include "Class1.h" // Cannot use forward declaration because of inheritance.
class Class2 : public Class1 { ... };

<br />

//Class3.h
class Class2;  // Forward declaration.
class Class3
{
   ...
   
private:
   
   Class2* mClass2;
};

-Saurabh

I tried

//Class1.h
#include "Class3.h"
class Class3;
class Class1 { ... };

//Class2.h
#include "Class1.h" // error C2504: 'Class1' : base class undefined
class Class2 : public Class1 { ... };

//Class3.h
#include "Class2.h"
class Class2;
class Class3 { ... };

but it doesn't work. Error C2504 as shown above