Re: Loki SmartPtr study: Policy orthogonality issues

From: rogeeff (rogeeff_at_[hidden])
Date: 2002-01-07 01:52:13

--- In boost_at_y..., Beman Dawes <bdawes_at_a...> wrote:

[...]

> 
> No, a validator does not need to recognize each and every policy.
> 
> Validators are like other generic components.  Their requirements 
include 
> inherited enums like is_array and disallow_array.
> 
> So the validator does something like:
> 
>     BOOST_STATIC_ASSERT( !disallow_array || !is_array )
> 
> Furthermore, if the validator is itself a policy, then a do-nothing 
version 
> can always be supplied.
> 
> For smart pointers there is probably a limited number of 
configuration 
> validity issues, so a policy class would probably be overkill.  The 
> framework class itself can handle it; isn't that already done by 
Loki 
> SmartPtr once or twice?

I an not exactly understand value of the validator as a policy.  If 
seems odd that I need to provide a validator to validate that other 
policies I provide will cowork propery. And if I changed behaviour - 
do I need to change the validator? I would assume that it is 
responcability of the framework to check that the policies I supply 
fits to each other. That may include requirenments that policies 
should have some specific traits defined ( like 'disallow_array' )

Gennadiy.

> 
> --Beman