Re: [boost] Random library: fn seed returning current seed value- why not

From: Matthias Troyer (troyer_at_[hidden])
Date: 2003-05-19 15:33:47

Hi Csaba,

Let me try to answer this question since Jens Maurer, the author of 
boost random is often very busy, and I am a frequent user of his 
library.

On Monday, May 19, 2003, at 05:21 PM, Csaba Szepesvari wrote:
> It would be nice to retrieve the current seed: I want to dump it so 
> that
> later I can reproduce the experiments I am running (that use the random
> library).
> Is there a bona fide reason not to return the seed (e.g. in the seed
> function).

Some generators use not only a single seed number but a seed block of 
many numbers. Instead of returning a single seed number (which is the 
not possible), there are operators << and >> to save the state into a 
std::ostream and to restore it from a std::istream

> The issue comes in when using seed without params (for "random"
> initialization).

AFAIK using seed() without a parameter will not give a "random" 
initialization but the same initialization at every call.

Matthias