Re: [boost] Re: Re: Re: Re: why is operator() not const in random numbergenerators?

From: Matthias Troyer (troyer_at_[hidden])
Date: 2003-04-17 01:31:49

On Thursday, April 17, 2003, at 02:14 AM, Thorsten Ottosen wrote:
> behind the scene some random number generator is used and it is called 
> from
> const functions.
> we don't want to propagate non-constness, since the class is just a 
> source
> of random directions ( anyway, such a propagation reminds me of Java's
> checked exceptions in the sence that it affects a whole lot of code 
> that is
> not supposed to be affected ).

OK. Here in principle the direction() functions do change the internal 
state. Howeverm in your application you do not care since you do not 
need reproducability of the results for your application. Then you can 
hide the fact that the internal state of the random number generator is 
changed - which is exactly what mutable is for.