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

Subject: Re: [Boost-users] boost::random: get same number sequences 32/64 bit?
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2010-02-01 10:36:54

AMDG

Sebastian Mach wrote:
> This was indeed the problem. The one box had boost 1.35 installed, the
> other one 1.41. Thanks for that hint.
>
>
> I guess this is a) not the right place and b) the interest is probably
> low (and let it be because it's not in the consciousness of many
> people):
>  * I realized that just replacing uniform_int.hpp with the older
> version (that is, in a project local directory) and renaming
> components was not easily possible
>  * hence it might be hard in the future to trust boost::random in the
> little corner where I really need portable random number sequences (as
> users will literally work with seeds)
>  * thus, I (and maybe some other persons) would love if, as with
> spirit::classic, backwards compatibility could be provided somehow,
> either via a typedef, a #define, or in the future with inline
> namespaces
>
> Of course, if there is already a way that "guarantees" (not as in
> law), I would be happy (after all, I am already happy to have a small
> regression test generator which initially showed me the problem; if
> there is interest, it is at
> http://gitorious.org/picogen/picogen/trees/master/trunk/kallisto/test
> :) ). Otherwise, I must really stick to hand written RNGs, which are
> less portable in code, but more portable in sequences, as no RNG-lib I
> know seems go have this kind of portability as a guideline.
>   

You could try using boost::mt19937 directly without
uniform_int.  The version of mt19937 in C++0x is
guaranteed to produce a specific sequence (Required
behavior: The 10000th consecutive invocation of a
default-constructed object of type mt19937
shall produce the value 4123659995.), and
the Boost.Random version will be kept consistent
with the standard.

Also, boost::uniform_int should not change again unless
there is a bug in it, and I'm about 99% certain that
it is completely correct now.

In Christ,
Steven Watanabe