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

Subject: Re: [boost] [Review.Contract] Vicente's review
From: Dave Abrahams (dave_at_[hidden])
Date: 2012-09-16 21:27:39

on Tue Sep 04 2012, Lorenzo Caminiti <lorcaminiti-AT-gmail.com> wrote:

> 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
>         )

+1 for "if." Andrzej's "enable_if" suggestion is nice and more explicit
too, but there's no syntax highlighting bonus.  I'm torn.

>         requires( // included in the function body

The fact that this is "included in the function body" is irrelevant I
think.  I guess the real point you're trying to make is that it
generates hard errors at acompile time when violated.  That suggests
something like "asserts" instead of "requires."

>             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
>         )
> ) {
>     // ...
> }

-- 
Dave Abrahams
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