void QuickSort(void *base, int count, int size,
  int (*compare)(const void *, const void *, void *), void *pointer);

static void
InternalQuickSort(char *left, char *right, int size,
  int (*compare)(const void *, const void *, void *), void *pointer)
{
  char *p = left;
  char *q = right;
  char *t = left;
  while (1)
  {
    while ((*compare)(p, t, pointer) < 0)
      p += size;
    while ((*compare)(q, t, pointer) > 0)
      q -= size;
    if (p > q)
      break;
    if (p < q)
    {
      int i;
      for (i = 0; i < size; i++)
      {
        char x = p[i];
        p[i] = q[i];
        q[i] = x;
      }
      if (t == p)
        t = q;
      else if (t == q)
        t = p;
    }
    p += size;
    q -= size;
  }
  if (left < q)
    InternalQuickSort(left, q, size, compare, pointer);
  if (p < right)
    InternalQuickSort(p, right, size, compare, pointer);
}

void
QuickSort(void *base, int count, int size,
  int (*compare)(const void *, const void *, void *), void *pointer)
{
  if (count > 1)
  {
    InternalQuickSort((char *) base, (char *) base + (count-1)*size, size,
      compare, pointer);
  }
}