Forward declaration.

[NoteMe]

Do anyone know this topic in and out?

I have a school assignment, and it is getting pretty big. And I keep getting errors like Object all ready defind in ***.obj. I guess this is because that more then one .h file is including the same class. And even if I use Include guards I am getting this error. I have heard that forward declarations can help me get rid of these problems. Anyone know how to use them properly. Like now the poblem is that I have a main file, that includes a terrain.h file, and the terrain.cpp file aslo includes the terrain.h file, and then the terrain.h file includes the file.h.


Then I am getting the error:

error LNK2005: "public: __thiscall cFile::cFile(void)" (??0cFile@@QAE@XZ) already defined in main.obj

and so on for the rest of the functions in the cFile class (in the file.h)