Re: [boost] [Review.Contract] Vicente's review

Subject: Re: [boost] [Review.Contract] Vicente's review
From: Andrzej Krzemienski (akrzemi1_at_[hidden])
Date: 2012-09-04 11:33:56

>
> Just to consider all alternatives, we could also do this:
>
> CONTRACT_FUNCTION(
>     template( typename To, typename From )
>         if( // used with enable_if in the declaration part
>              is_convertible<From, To>::value,
>              is_convertible<To, From>::value
>         )
>         requires( // included in the function body
>             static_assert(sizeof(To) >= sizeof(From), "destination too
> small"),
>             boost::Copyable<From>
>         )
>     (To*) memcopy ( (To*) to, (From*) from )
>         precondition(
>             to; // pointer not null
>             from; // pointer not null
>         )
> ) {
>     // ...
> }
>

We (or I) are too much used to "requires" implying concepts, implying
enable-if behavior. So I would find this one confusing. Although the "if"
makes sense. One other alternative would be:
keyword "enable_if" -- for soft conditions
keyword "expect" or "check" -- for hard conditions

But your first suggestion is satisfactory.
Regards,
&rzej