Question

I have two classes

RequestManager.h

#ifndef REQUESTMANAGER_H
#define REQUESTMANAGER_H

#include "RequestClient.h"
class RequestManager
{
public:
     void AddReqeustItem(RequestClient *req);

private:
 std::list<RequestClient*> m_reqClientContainer;
};
#endif

RequestClient.h

#ifndef REQUESTCLIENT_H
#define REQUESTCLIENT_H

class RequestManager; // Forward declaration to avoid cyclic inclusion.

class RequestClient {
public:
void CreateRequest(RequestManager* pManager)
{
  // ... I am creating a request.
  pManager->AddReqeustItem(req);
};
#endif

In the code above I am getting error undefined RequestManager in Request client class. What is the problem and how can I solve it?

Answer 1

You cannot use a type with only a forward declaration. Forward declaration are used to say to compiler that type exists but compiler does not know the content of the type.

My advice:

• In header file, I would only define class and function members. So forward declaration is possible if only pointer are used.
• In body file, write the code your member function and include the header files