#pragma pack(push,1)                                    
struct _stdcallthunk {                                  
[color=#FF0000]    DWORD   m_mov;     // mov dword ptr [esp+0x4], pThis
                       // (esp+0x4 is hWnd)             
    DWORD   m_this;    // Our CWindowImpl this pointer  
    BYTE    m_jmp;     // jmp WndProc              
    DWORD   m_relproc; // relative jmp  [/color]                
                                                        
    BOOL Init(DWORD_PTR proc, void* pThis) {            
        m_mov = 0x042444C7; //C7 44 24 0C               
        m_this = PtrToUlong(pThis);                     
        m_jmp = 0xe9;                                   
        m_relproc = DWORD((INT_PTR)proc                
            ((INT_PTR)this+sizeof(_stdcallthunk)));     
        // write block from data cache and              
        //  flush from instruction cache                
        FlushInstructionCache(GetCurrentProcess(), this,
            sizeof(_stdcallthunk));                     
        return TRUE;                                    
    }                                                   
                                                        
    // some thunks will dynamically allocate the        
    // memory for the code                              
[color=#FF0000]    void* GetCodeAddress() {                            
        return this;                                    
    }  [/color]                                            
};                                                      
#pragma pack(pop)