template <class T> class Thunk
{
    BYTE asm86[12];
public:
    typedef void (__stdcall T::*ThunkType)();
 
    void InitThunk(ThunkType method, const T *pthis)
    {
        union uPtr { BYTE *byte; DWORD *dword; ThunkType method; };
 
        uPtr pAsm86;
        pAsm86.byte = asm86;
        uPtr pFn;
        pFn.method = method;
 
        *pAsm86.byte++    = 0x58; //pop eax
        *pAsm86.byte++    = 0x68; //push pthis
        *pAsm86.dword++    = (DWORD)pthis;
        *pAsm86.byte++    = 0x50; //push eax
        *pAsm86.byte++    = 0xE9; //jmp method
        *pAsm86.dword++    = (DWORD)pFn.dword - (DWORD)(this+1);
 
        //This function is valid only on multiprocessor computers.
        //FlushInstructionCache(GetCurrentProcess(), this, sizeof(*this));
    }
 
    FARPROC GetThunk() const
    {
        return (FARPROC)this;
    }
};
 
class Window : private Thunk<Window>
{
    LRESULT CALLBACK WindowProc(HWND,UINT,WPARAM,LPARAM);
public:
    Window()
    {
        InitThunk((Thunk<Window>::ThunkType)WindowProc,this);
        WNDCLASSEX wc;
        wc.lpfnWndProc=(WNDPROC)GetThunk();    
    }    
};