Re: [boost] [review][constrained_value] Review of Constrained ValueLibrary begins today

Subject: Re: [boost] [review][constrained_value] Review of Constrained ValueLibrary begins today
From: Thorsten Ottosen (thorsten.ottosen_at_[hidden])
Date: 2008-12-09 07:12:03

vicente.botet skrev:
> ----- Original Message ----- 
> From: "Robert Kawulak" <robert.kawulak_at_[hidden]>

>> In some cases the error policy needs to access the constraint even if it does
>> not need to modify it. For example, the wrap policy needs to query the bounds to
>> perform the modulo arithmetic operations.
> 
> Hi,
> 
> I find that the extreme example "bounded object with memory" is not a good example of constrained_value because not constrained at all. It is the example of what can be done with the current interface but that shouldn't be able to be done with  a constrained value. I don't understand why an error policy can modify the value or the constraint. I would prefer an error policy taking only two in-parameters (by value or const&) the new value and the constraint.
> 
> The wrapping and cliping classes are not exactly constrained values, they are adapting a value of a type to a constrained value. So I would prefer to have a different class for them taking a constraint adaptor that would take the value by reference and adapt it to the constraint.

I agree. This seems like a better division of responsibility.

-Thorsten