Re: [boost] [Random] uniform_int vs. uniform_real vs. uniform_01

From: Douglas Gregor (dgregor_at_[hidden])
Date: 2005-01-05 09:17:15

On Dec 31, 2004, at 10:51 AM, Jens Maurer wrote:
>> Looking at the source to uniform_real, the problem is obvious:
>>   result_type operator()(Engine& eng) { return eng() * (_max - _min) 
>> + _min; }
>
> Yes.  Fixed.

It doesn't seem to be completely fixed, although it might be because I 
am wrong. In the fix I'd sent, eng() - eng.min() would first be casted 
to the result_type (a real type, of course), the we divide by eng.max() 
- eng.min() and adjust to uniform_real's range. In the code in CVS, the 
cast isn't performed until after the division. So when the engine 
returns integer values (as linear_congruential does), we don't get 
proper results. Is it wrong to use engines returning integer values 
with uniform_real? If so, we should have a static assert in there.

        Doug