Re: [boost] Ranged type mini-library submission

From: Jeff Garland (jeff_at_[hidden])
Date: 2004-05-17 10:29:04

On Mon, 17 May 2004 10:51:19 -0400, christopher diggins wrote

> > http://sourceforge.net/projects/boost-sandbox/
> 
> Would it be acceptable that I post on my web site:
> http://www.cdiggins.com/constrained_value.hpp until we arrive at 
> consensus, at which i point I submit it to the sandbox?

No problem, it's just that we will probably get this developed and then we
will have to wait awhile for a review slot.  In the meantime it's easier to do
a cvs checkout for various updates and such.  But seriously, there's no rush...

> I too like the idea of a validation policy. You propose an 
> interesting technique but I am not convinced it is the best option 
> for what we want. If constraints_policy does the validation then the 
> error handling policy could just more easily be passed as an 
> argument to the constraints policy. 

Yep, I agree.

> This leaves us with:
> 
> template< class constraints_policy,
>     bool implicit_conversion_policy = true>
> class constrained_value  { ... }

But I think you the 'min' and 'max' function requirement is now out of place
on the core template.  If you have a constrained range, then it makes sense,
but if I'm checking for 'divisible by 4' then I'll be perplexed as to why I
have to provide min and max in my constraints_policy class.  However, if you
derive from the constraints_policy it can provide any interfaces it wants to
the user.

Jeff