[Bug c++/14417] New: output streams and post-increment operator have incorrect output.

[mcvick_e at iname dot com]

Utilizing the post increment operator within a stream operation does not result
in the expected output.  Output is reversed.  Based on the grammer of the
language, this should work as expected and not as currently implemented.

THe following program will replicate the problem:

#include <iostream>
#include <fstream>

using namespace std;


char *str = "0123456789ABCDEF";

int main(int argc, char **argv)
{
   char *ptr;

#if defined(COUT_TOO)
   ptr = str;

   cout << *ptr++ << *ptr++ << ' ';
   cout << *ptr++ << *ptr++ << ' ';
   cout << *ptr++ << *ptr++ << ' ';
   cout << *ptr++ << *ptr++ << ' ';
   cout << *ptr++ << *ptr++ << ' ';
   cout << *ptr++ << *ptr++ << ' ';
   cout << *ptr++ << *ptr++ << ' ';
   cout << *ptr++ << *ptr++ << ' ';
   cout << endl;
#endif

   ostream  *outStream;

   outStream = new ofstream("foo.txt");
   ptr = str;

   *outStream << *ptr++ << *ptr++ << ' ';
   *outStream << *ptr++ << *ptr++ << ' ';
   *outStream << *ptr++ << *ptr++ << ' ';
   *outStream << *ptr++ << *ptr++ << ' ';
   *outStream << *ptr++ << *ptr++ << ' ';
   *outStream << *ptr++ << *ptr++ << ' ';
   *outStream << *ptr++ << *ptr++ << ' ';
   *outStream << *ptr++ << *ptr++ << ' ';
   *outStream << endl;

   delete outStream;

   // Same concept, different syntax works.

#if defined(COUT_TOO)
   ptr = str;

   cout << *ptr++;
   cout << *ptr++ << ' ';
   cout << *ptr++;
   cout << *ptr++ << ' ';
   cout << *ptr++;
   cout << *ptr++ << ' ';
   cout << *ptr++;
   cout << *ptr++ << ' ';
   cout << *ptr++;
   cout << *ptr++ << ' ';
   cout << *ptr++;
   cout << *ptr++ << ' ';
   cout << *ptr++;
   cout << *ptr++ << ' ';
   cout << *ptr++;
   cout << *ptr++ << ' ';
   cout << endl;
#endif

   outStream = new ofstream("bar.txt");
   ptr = str;

   *outStream << *ptr++;
   *outStream << *ptr++ << ' ';
   *outStream << *ptr++;
   *outStream << *ptr++ << ' ';
   *outStream << *ptr++;
   *outStream << *ptr++ << ' ';
   *outStream << *ptr++;
   *outStream << *ptr++ << ' ';
   *outStream << *ptr++;
   *outStream << *ptr++ << ' ';
   *outStream << *ptr++;
   *outStream << *ptr++ << ' ';
   *outStream << *ptr++;
   *outStream << *ptr++ << ' ';
   *outStream << *ptr++;
   *outStream << *ptr++ << ' ';
   *outStream << endl;

}


The above program was compiled with the following command:

g++ -O0 -o foobar test.cxx -DCOUT_TOO


The output on the screen and found in the files is thus:

10 32 54 76 98 BA DC FE 
01 23 45 67 89 AB CD EF 

The specs of the compiler obtained with g++ -v is:

Reading specs from /usr/lib/gcc-lib/i386-redhat-linux/3.3.3/specs
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --enable-shared --enable-threads=posix
--disable-checking --disable-libunwind-exceptions --with-system-zlib
--enable-__cxa_atexit --host=i386-redhat-linux
Thread model: posix
gcc version 3.3.3 20040216 (Red Hat Linux 3.3.3-2)

I have even tried the latest snapshot of GCC 3.3.3 and it fails as well.  I also
compiled 3.3.1 and used it with the same results.

-- 
           Summary: output streams and post-increment operator have
                    incorrect output.
           Product: gcc
           Version: 3.3.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: mcvick_e at iname dot com
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i386-redhat-linux
  GCC host triplet: i386-redhat-linux
GCC target triplet: i386-redhat-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14417