#define ALLOW_INSTRUCTOR_CODE
/***************************************************************************
 ***************************************************************************
 ****** BEFORE BEGINNING OR TURNING IN THIS EXERCISE IT IS  EXTREMELY ******
 ****** IMPORTANT THAT YOU READ, FULLY UNDERSTAND, AND ADHERE TO  THE ******
 ****** REQUIREMENTS STATED  IN  THE  DOCUMENT  TITLED,   "ASSIGNMENT ******
 ****** SUBMISSION REQUIREMENTS", DOWNLOADABLE FROM  THE  COURSE  WEB ******
 ****** SITE.                                                         ******
 ***************************************************************************
 **************************************************************************/



/***************************************************************************
 ************* C/C++ Programming 2:  Assignment 7 - Exercise 3 *************
 ********* BEGIN EXERCISE REQUIREMENT - THIS MUST BE A "C" PROGRAM *********
 ***************************************************************************

   (2 points)  Write function ReverseEndian:

      ReverseEndian syntax:
         void *ReverseEndian(void *p, size_t size);
      Parameters:
         p -    a pointer to the scalar object to be reversed
         size - the number of bytes in the object
      Synopsis:
         Swaps the bytes in the scalar object in <p>, thereby converting it
         from big endian to little endian, or vice versa.
      Return:
         <p>

 ***************************************************************************
 ************************ END EXERCISE REQUIREMENT *************************
 **************************************************************************/



/***************************************************************************
 * BEFORE PRINTING THIS ASSIGNMENT  TO  TURN  IN, DELETE  THIS  COMMENT  AND
 * EVERYTHING ABOVE IT.
 **************************************************************************/

/*
 * TODO:
 *   REPLACE THIS COMMENT WITH YOUR TITLE BLOCK.
 */

/*
 * TODO:
 *    REPLACE THIS COMMENT WITH YOUR  C  CODE, PLUS  ANYTHING  NECESSARY  TO
 *    SUPPORT MY TEST CODE BELOW.  DO NOT INCLUDE ANY UNNEEDED HEADER FILES!
 */

/***************************************************************************
 * BEFORE PRINTING THIS ASSIGNMENT  TO  TURN  IN, DELETE  THIS  COMMENT  AND
 * EVERYTHING BELOW IT.
 **************************************************************************/

/*
 ***** Change nothing below this comment without instructor permission. ****
 * Everything that follows was written to help test/verify your code.  You
 * do not need to understand the details of my code to write yours!
 */
#ifdef ALLOW_INSTRUCTOR_CODE
#define TestIt(a, b) TestReverse((void *)&(a),\
                     ReverseEndian((void *)&(b), sizeof(b)), sizeof(b))
void TestReverse(const void *before, const void *after, size_t size);

int main(void)
{
   /* Some objects to test... */
   char ch = 0x01, ch1 = ch;
   short sh = 0x0123, sh1 = sh;
   long lo = 0x01234567, lo1 = lo;
   float fl = 1234.567e27F, fl1 = fl;
   double db = 123456.567890, db1 = db;
   long double ld = 987654.321053e-204L, ld1 = ld;
   void *vp = (void *)0x0123, *vp1 = vp;
   char *cp = (char *)0x4567, *cp1 = cp;
   char *ip = (char *)0x89AB, *ip1 = ip;

   TestIt(ch1, ch);
   TestIt(sh1, sh);
   TestIt(lo1, lo);
   TestIt(fl1, fl);
   TestIt(db1, db);
   TestIt(ld1, ld);
   TestIt(vp1, vp);
   TestIt(cp1, cp);
   TestIt(ip1, ip);

   printf("ReverseEndian succeeded!\n");

   return EXIT_SUCCESS;
}

void TestReverse(const void *before, const void *after, size_t size)
{
   const char *cpBfore = (const char *)before;
   const char *cpAfter = (const char *)after;
   const char *tail;

   for (tail = cpBfore + (size - 1); size; --size)
      if (*tail-- != *cpAfter++)
      {
         fprintf(stderr, "ReverseEndian failed!\n");
         exit(EXIT_FAILURE);
      }
}
#endif