Re: Boost vs Std library features

From: Peter Dimov (pdimov_at_[hidden])
Date: 2023-11-30 00:03:04

Niall Douglas wrote:
> On 29/11/2023 22:21, Peter Dimov via Boost wrote:
> > Niall Douglas wrote:
> >> There were still some big design mistakes in 11 - I still find
> >> `<random>` very unfortunate and entirely avoidable at the time,
> >
> > <random> is mostly fine. The generators and the concepts reflect
> > the state of the art as it was then, and aren't entirely broken even
> > today.
> 
> I really have to disagree :)
> 
> There is this axis randomness:
> 
> 1. Predictable randomness from a specified starting state.
> 
> 2. Unpredictable randomness with same semantics on all architectures.
> 
> There is also the quality vs fast axis.
> 
> On the quality vs fast axis, I could just about agree with you about
> <random>.
> 
> On that other axis though, <random> is a complete design failure. One
> needs the ability to copy states, serialise and deserialise states, and
> to get identical output on all architectures and platforms for a given
> starting state.
> 
> One also must not have an engine perform 20x worse on one platform than
> another if one is to write usefully portable code.

I don't understand your objections, sorry.

Are you saying that the generators in <random> don't offer the ability
to copy, serialize, deserialize and give identical output? Because they do.

Which engine performs 20x worse?