klasa tworząca i obsługująca okno

Mam taką klase:

#include <windows.h> 

static TCHAR lpszAppName[] = TEXT( "API Windows" ); 


class playlist
{
    public:
        playlist(HINSTANCE hInstance);
        LRESULT CALLBACK MainWndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
    private:
        MSG msg;
        WNDCLASS wndclass;
        HWND hWnd;
        
}

playlist::playlist(HINSTANCE hInstance)
{
wndclass.style = CS_HREDRAW | CS_VREDRAW; 
wndclass.lpfnWndProc = MainWndProc; 
wndclass.cbClsExtra = 0; 
wndclass.cbWndExtra = 0; 
wndclass.hInstance = hInstance; 
wndclass.hIcon = NULL; 
wndclass.hCursor = LoadCursor(NULL, IDC_ARROW); 
wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH); 
wndclass.lpszMenuName = NULL; 
wndclass.lpszClassName = lpszAppName; 
RegisterClass(&wndclass);

hWnd = CreateWindow(lpszAppName, lpszAppName, 
WS_OVERLAPPEDWINDOW | WS_CLIPCHILDREN | WS_CLIPSIBLINGS, 
CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL); 
 
ShowWindow(hWnd, SW_SHOW); 
UpdateWindow(hWnd); 

while(GetMessage(&msg, NULL, 0, 0)) 
{ 
TranslateMessage(&msg); 
DispatchMessage(&msg); 
}  
} 

LRESULT CALLBACK playlist::MainWndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam) 

{ 
switch (uMsg) 
{ 

case WM_CREATE: 

break; 

case WM_DESTROY: 

PostQuitMessage(0);
break; 

case WM_KEYDOWN: 

break; 

default: 

return (DefWindowProc(hWnd, uMsg, wParam, lParam)); 

} 
return(0L); 
} 

Jednak ona nie dziala:( Kompilator zwraca:
playlistclass.cpp ISO C++ forbids defining types within return type
playlistclass.cpp return type specification for constructor invalid

playlistclass.cpp: In constructor playlist::playlist(HINSTANCE__*)': playlistclass.cpp:21: no matches converting function MainWndProc' to type `
LRESULT ()(struct HWND__, unsigned int, unsigned int, long int)'
playlistclass.cpp candidates are: LRESULT playlist::MainWndProc(HWND__*,
unsigned int, unsigned int, long int)

Co jest nie tak??

MainWndProc musi byc metoda statyczna tej klasy, lub funkcja globalna.

ustawiłem ta funkcje jako globalna, ale dostaje jeszcze:
playlistclass.cpp ISO C++ forbids defining types within return type
playlistclass.cpp return type specification for constructor invalid

Proponowalbym wstawic brakujacy srednik ;)