random_shuffle behavior differs, VS 2003 versus VS 2005

microsoft.public.dotnet.framework

5 May 2006 8:52 PM

Askance

random_shuffle function produces different results for debug and
release executables when compiled with /clr

This console app, built without /clr using VS 2005, produces identical
results for debug and release executables. But add /clr to the compile
line and two different results occur. The debug result matches that of
the "non-clr" executables.

This poses a serious problem for QC of mixed-mode applications built
with VS 2005. Lack of reproducibility of release executable behavior
in a debugging environment is unacceptable. This discrepancy has not
been observed using VS 2003.

Will this behavior be fixed in a future release of VS 2005?

// Shuffling.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <iostream>            // C++ STL cout, endl
#include <numeric>            // C++ STL generic numeric algorithms
(partial_sum)
#include <queue>            // Standard C++ Library queue

using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
    // create the deque (1, 2, ... 10) . . .
    std::deque<int>        myDeque(10, 1);
    partial_sum(myDeque.begin(), myDeque.end(), myDeque.begin());

    for (unsigned int i = 0; i < myDeque.size(); ++i) {
        cout << myDeque[i] << ' ';
    }
    cout << endl;

    // . . . and randomize it
    random_shuffle (myDeque.begin(), myDeque.end());
    for (unsigned int i = 0; i < myDeque.size(); ++i) {
        cout << myDeque[i] << ' ';
    }
    cout << endl;

    getchar();
    exit(0);
}

Debug (no /clr)
1 2 3 4 5 6 7 8 9 10
9 2 10 3 1 6 8 4 5 7

Release (no /clr)
1 2 3 4 5 6 7 8 9 10
9 2 10 3 1 6 8 4 5 7

Debug /clr
1 2 3 4 5 6 7 8 9 10
9 2 10 3 1 6 8 4 5 7

Release /clr
1 2 3 4 5 6 7 8 9 10
10 1 9 2 4 8 5 6 7 3