int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, 
                    PSTR szCmdLine, int iCmdShow)
  {  
     win w(hInstance, iCmdShow, "winapp", 
           "winapp: First program with short WinMain-function");
     return w.result();
  }

//win.h

#define STRICT
#include <windows.h>

LRESULT CALLBACK WndProc(HWND hWnd, UINT iMsg, 
                         WPARAM wParam, LPARAM lParam);

struct win
  {     
    win (HINSTANCE hInstance0, int iCmdShow0, 
         PSTR szAppName0, PSTR szWindowCaption0);

    int result ();

    int iCmdShow;         //For passing through ShowWindow
    WNDCLASSEX wndclass;
    HWND hWnd,            //Handle for mainwindow
         hDlg;            //Handle for modeless dialogbox
    PSTR szAccel;         //Name accelerator table

    //Arguments for CreateWindow:
    PSTR szAppName;       //registered classname
    PSTR szWindowCaption; //address of windowname
    DWORD dwStyle;        //windowstyle
    int x;                //horizontal position of window
    int y;                //vertical position of window
    int nWidth;           //width
    int nHeight;          //height
    HWND hWndParent;      //parent-window
    HMENU hMenu;          //menuhandle
    HINSTANCE hInstance;  //application-instance
    LPVOID lpParam;       //window-creation-data
 };

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, 
                    PSTR szCmdLine, int iCmdShow)
 {  
   win w(hInstance, iCmdShow, "winapp", 
         "winapp: First program with short WinMain-function");
   w.wndclass.hCursor = LoadCursor(NULL, IDC_CROSS);
   return w.result();
 }

// win.cpp: Implementation of the structure win;
//          After compiling, link with application-file

#include "win.h"

win::win(HINSTANCE hInstance0, int iCmdShow0, 
         PSTR szAppName0, PSTR szWindowCaption0)
 {
   iCmdShow = iCmdShow0;

   //store the arguments for CreateWindow in the structure win:
   szAppName = szAppName0;
   szWindowCaption = szWindowCaption0;
   dwStyle = WS_OVERLAPPEDWINDOW;
   x = y = 0;
   nWidth = GetSystemMetrics(SM_CXSCREEN);
   nHeight = GetSystemMetrics(SM_CYSCREEN);
   hWndParent = NULL;
   hMenu = NULL;
   hInstance = hInstance0;
   lpParam = NULL;

   //Fill wndclass just for now:
   wndclass.cbSize = sizeof(wndclass);
   wndclass.style = CS_HREDRAW | CS_VREDRAW;
   wndclass.lpfnWndProc = WndProc;
   wndclass.cbClsExtra = 0;
   wndclass.cbWndExtra = 0;
   wndclass.hInstance = hInstance;
   wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
   wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
   wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
   wndclass.lpszMenuName = NULL;
   wndclass.lpszClassName = szAppName;
   wndclass.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
   wndclass.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
   hDlg=0;
   szAccel = NULL;
 }


int win::result()
 {
   RegisterClassEx(&wndclass);
   hWnd = CreateWindow(szAppName, szWindowCaption, dwStyle, 
                       x, y, nWidth, nHeight, hWndParent,
                       hMenu, hInstance, lpParam);
   ShowWindow(hWnd, iCmdShow);
   UpdateWindow(hWnd);
   MSG msg;
   HACCEL hAccel = (szAccel ? LoadAccelerators(hInstance, szAccel) : 0);
   while (GetMessage(&msg, NULL, 0, 0))
     { 
       if (hDlg == 0 || !IsDialogMessage(hDlg, &msg))
         { 
           if (hAccel == 0 || !TranslateAccelerator(hWnd, hAccel, &msg))
             { 
               TranslateMessage(&msg);
               DispatchMessage(&msg);
             }
        }
     }
   return msg.wParam;
 }

bcc32 -c -W win

cl /c win.cpp