C / C++ / MFC

#define DIRECTSOUND_VERSION 0x0800  /* Version 8.0 */

#ifndef DIRECTSOUND_VERSION

#if (NTDDI_VERSION < NTDDI_WINXP) /* Windows 2000 */
#define DIRECTSOUND_VERSION 0x0700  /* Version 7.0 */
#elif (NTDDI_VERSION < NTDDI_WINXPSP2 || NTDDI_VERSION == NTDDI_WS03) /* Windows XP and SP1, or Windows Server 2003 */
#define DIRECTSOUND_VERSION 0x0800  /* Version 8.0 */
#else /* Windows XP SP2 and higher, Windows Server 2003 SP1 and higher, Longhorn, or higher */
#define DIRECTSOUND_VERSION 0x0900  /* Version 9.0 */
#endif

#endif // DIRECTSOUND_VERSION

GoToCellDialog::GoToCellDialog(QWidget *parent)
{
  QDialog(parent); // Call parent constructor
  ... // rest of initialisation
}

class A
{
  int a;

  int func()
  {
    // Because we are inside class A, this refers to the current instance of A when func is called
    // Therefore, the following two lines are equivalent:
    return this->a; 
    return a;
  }
};

class B : A
{
  int b;

  int funcB()
  {
    // Again equivalent are:
    return this->b;
    return b;
    // Now this actually refers to an instance of object B, but because B is derived from A
    // we also have access to a, so also equivalent are:
    return this->a;
    return a;
  }
}

int main()
{
  // 'this' does not exist here, because main is not part of a class
}

class C
{
  int c;
  static sc;

  static int funcC()
  {
    // Here, becaus funcC is static (so it does not belong to an instance of a class)
    // 'this' doesn't exist either. So, you could write:
    return sc;
    // But you could not write:
    return this->sc; //Error: this does not exist in a static function
    return this->c; // This also produces an error
  }
}