So I have a header file like this:

[source lang="cpp"]class ZFXRenderDevice {
protected:
HWND m_hWndMain; // application main window
HWND m_hWnd[MAX_3DHWND]; // 3D render window handle
UINT m_nNumhWnd; // number of hwnds in array
UINT m_nActivehWnd; // which one is active (0=main hWnd)
HINSTANCE m_hDLL; // dll module handle
DWORD m_dwWidth; // screen width
DWORD m_dwHeight; // screen height
bool m_bWindowed; // windowed mode?
char m_chAdapter[256]; // graphics adapter name
bool m_bRunning; // after succesful initialization
FILE *m_pLog; // log file


public:
ZFXRenderDevice(void) {};
virtual ~ZFXRenderDevice(void) {};


// INIT/RELEASE STUFF:
// ===================

// initialize engine, should first display dialog to select
// graphics adapter and mode, and then start the 3D API
virtual HRESULT Init(HWND, const HWND*, int, int, int, bool)=0;
virtual HRESULT InitWindowed(HWND, const HWND*, int, bool)=0;

// release API specific stuff
virtual void Release(void)=0;

// is initialized?
virtual bool IsRunning(void)=0;


// RENDERING STUFF:
// ================

// switch swap chain to hwnd in array from Init()
virtual HRESULT UseWindow(UINT nHwnd)=0;

// clear buffers and prepare for rendering
virtual HRESULT BeginRendering(bool bClearPixel,
bool bClearDepth,
bool bClearStencil)=0;

// end rendering and flip pixel buffer to front
virtual void EndRendering(void)=0;

// clear pixel-, depth-, stencil-buffer
virtual HRESULT Clear(bool, bool, bool)=0;

// change background color
virtual void SetClearColor(float fRed, float fGreen, float fBlue)=0;
}; // class

typedef class ZFXRenderDevice *LPZFXRENDERDEVICE;
/*----------------------------------------------------------------*/


extern "C" {
HRESULT CreateRenderDevice(HINSTANCE hDLL, ZFXRenderDevice **pInterface);


HRESULT ReleaseRenderDevice(ZFXRenderDevice **pInterface);
typedef HRESULT (*RELEASERENDERDEVICE)(ZFXRenderDevice **pInterface);
}
/*----------------------------------------------------------------*/

[/source]

So when an instance of that class gets created,the variables in it get created too right? But what about that extern "C"? From what I googled I found that those functions are decleared here,but will be implemented somewhere else.
And the typedef? I mean the typedef creates a pointer type called RELEASERENDERDEVICE.

What I don't understand is why put that typedef under extern? Why not just put it above the class?! I mean it's just a definition,it doesn't actually create a RELEASERENDERDEVICE pointer.

so the c++ mangling problem affects even function pointers? I thought only functions...

Are you sure that the name mangling problem affects function pointers too?!