Re: [boost] Re: Re: Formal Review in progress

From: Peder Holt (peder.holt_at_[hidden])
Date: 2005-05-28 07:20:16

On 5/28/05, Arkadiy Vertleyb <vertleyb_at_[hidden]> wrote:
> "Peder Holt" <peder.holt_at_[hidden]> wrote
> 
> > I did some tests on VC8 beta, and it compiles the testcase in half the
> > time compared to the present implementation of typeof_impl. As far as
> > I have been able to test, it also works around the compiler bug for
> > VC8 discussed earlier.
> >
> > Here is a more detailed sketch of the proposed solution:
> >
> > namespace boost {namespace type_of{
> >     template<typename T>
> >     struct encode_result {
> >         typedef typename encode_type<BOOST_TYPEOF_VECTOR(0)<>,
> > T>::type encoded_type;
> >         typedef typename mpl::size<encoded_type>::type size;
> >         char (&value0)[...];
> >         char (&value1)[...];
> >         char (&value2)[...];
> >         ...
> >         char (&value50)[...];
> >     };
> >
> >     template<class T>
> >     encode_result<T> typeof_result(const T&);
> > }}
> > #define BOOST_TYPEOF_AT(n, expr)
> > sizeof(boost::type_of::typeof_result(expr).BOOST_PP_CAT(value,n))
> 
> Interesting... Let me guess:
> 
> char(&value2)[mpl::at<encode<T>::type, mpl::int<(2 < size) ? 2 : 0>
> >::type::value]; //?

Yep :)

        char(&value2)[mpl::at<encoded_type,mpl::int_<(2 < size::value)
? 2 : 0>
>::type::value];

Peder

> 
> Regards,
> Arkadiy
> 
> 
> 
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