Re: [boost] Proposal for aiding trust issues through object design.

From: Christopher Granade (cgranade_at_[hidden])
Date: 2006-05-26 17:24:56

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Giovanni Piero Deretta wrote:
> I had some toughts about this problem too, but my ideal solution would
> be the other way around. Everything is trusted by default. External objects
> are wrapped in
> an untrusted<> wrapper. An object specific function would check the imput
> and remove the wrapper.
> 
> It would be used like this:
> 
>   class my_input_checker  {...};
>   typedef untrusted<std::string, my_input_checker>  untrusted_string;
> 
>   untrusted_string external_input();
>   ...
>   untrusted_string input = external_input();
>   try {
>     std::string checked_input = input,
>   } catch(const trust_exception&) {
>     ...
>   }
> 
> On conversion, untrusted call the input checker. On error the conversion
> fails and trows
> a trust_exception.
> This way, an untrasted object has a diferent type than a trusted one (no run
> time flags). Most of the code deals only with ordinary (trusted) objects
> (and need no change), while input functions returns untrusted objects.
> 
> Just my 0.02 euros.
> _______________________________________________
> Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
> 
I really like the point about not using run-time flags. Seems that your
way would be much simpler to implement. Would anyone else want to see
this idea become reality?

- -- Christopher Granade
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