[Boost-users] boost::random: get same number sequences 32/64 bit?

Subject: [Boost-users] boost::random: get same number sequences 32/64 bit?
From: Sebastian Mach (phresnel_at_[hidden])
Date: 2010-01-31 12:04:54

Hello list,

today I found out that boost::random, at least the combination

boost::mt19937 rng(<seed>);
typedef boost::uniform_int<int> dist_t;
dist_t dist (<min>, <max>);
boost::variate_generator<
        boost::mt19937&,
        dist_t
> rand_ (rng, dist);

will give me different results depending on whether I use "g++ (Debian
4.3.2-1.1) 4.3.2"  (with sizeof(long)=8) or "g++.exe (TDM-2 mingw32)
4.4.1" (with sizeof(long)=4).

This testcase:
++
#include <boost/random.hpp>

boost::mt19937 rng(1);
typedef boost::uniform_int<int> dist_t;
dist_t dist (0, 16);
boost::variate_generator<
        boost::mt19937&,
        dist_t
> rand_ (rng, dist);

int main () {
        for (int i=0; i<6; ++i) {
                std::cout << rand_() << std::endl;
        }
}
--
will print 16 8 1 6 0 12 with the 64bit variant variant, but 7 16 12
15 0 2 with the 32bit variant.
Is there a (preferably portable) way to ensure that they will be the
same on all 32bit+ machines?
Otherwise this would be a real stopper to use boost::random for me,
and I'd have to go back to libcoyotl's Mersenne Twister, which gives
consistent results, upon which I really depend.
Sincerely
Sebastian Mach
phresnel_at_[hidden]