Help need with c++ forward declarations

I am new to using forward declarations. I thought I had understood quite a bit of it until I got this error. Seems there is something really really basic that I miss. can some one of you help me with this error???

src/BaseBodyDynamics.cpp:15: error: invalid use of incomplete type 'struct Xlib::Quatf'
include/BaseBodyDynamics.h:19: error: forward declaration of 'struct Xlib::Quatf'


basically i tried forward declaring the class Quat . Then had a variable declared in the header file which was a pointer. When i try using the variable in the cpp file after including Quaternion.h which is the parent file of Quat I get this error.

A small code snippet

Code:

---

//Header file
class *Quat;
Quatf* m_qSObjectSpin;

//cpp file
m_qSObjectSpin->normalize();

---

Actually the quaternion is a part of the struct i have defined in my class..I am not sur eif that is causing the error or if there is any better way to do this.

Cheers

header file...

Code:

---

class CObject;

class CObjectManager {
public:
  CObject *m_ptrObjects;
  int m_numObjects;
};

---

source file...

Code:

---

#include "ObjectManager.h"
#include "Object.h"
  ...

---

It seems I have given exactly the same format in the header file and the cpp file as told above.. But still i get the same error

src/BaseBodyDynamics.cpp:15: error: invalid use of incomplete type 'struct Xlib::Quatf'
include/BaseBodyDynamics.h:19: error: forward declaration of 'struct Xlib::Quatf'

Can someone help me with this