Re: [Boost-users] mpl::transform<...> --- compile error: is not derived from type

Subject: Re: [Boost-users] mpl::transform<...> --- compile error: is not derived from type
From: e r (erwann.rogard_at_[hidden])
Date: 2008-09-06 23:44:59

e r wrote:
> hi,
> 
> here's the problem i have:
>     struct my{
>       template<typename UInt>
>       struct apply{
>            typedef mpl::int_<UInt::value> type;
>       };
>    };
> 
>     template<int First,int Last>
>     struct id_range{
>         typedef mpl::transform<
>             mpl::range_c<int,First,Last>
>             , my
>             , mpl::back_inserter< mpl::vector<> >
>         >::type type;
> 
> /home/er/cpp/boost/random/mcmc/id_range.hpp|32|error: type
> ‘boost::mpl::transform<boost::mpl::range_c<int, First, Last>,
> boost::random::mcmc::<unnamed>::my,
> boost::mpl::back_inserter<boost::mpl::vector<mpl_::na, mpl_::na,
> mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na,
> mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na,
> mpl_::na, mpl_::na, mpl_::na, mpl_::na> >, mpl_::na>’ is not derived
> from type ‘boost::random::mcmc::id_range<First, Last>’|
> 
> however, for example, this --instead-- compiles fine:
> 
>     struct id_range{
>         typedef mpl::transform<
>             mpl::range_c<int,1,3>
>             , my
>             , mpl::back_inserter< mpl::vector<> >
>         >::type type;
>  };
> any suggestion appreciated. thanks!

and also, although the second version compiles, i have

    BOOST_MPL_ASSERT( (
            is_same<
                id_range::type,
                mpl::vector< mpl::int_<1>, mpl::int_<2>, mpl::int_<3> >
            >
    ) );

causes,

error: no matching function for call to
‘assertion_failed(mpl_::failed************
boost::is_same<boost::mpl::v_item<mpl_::int_<2>,
boost::mpl::v_item<mpl_::int_<1>, boost::mpl::vector<mpl_::na, mpl_::na,
mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na,
mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na,
mpl_::na, mpl_::na, mpl_::na, mpl_::na>, 0>, 0>,
boost::mpl::vector<mpl_::int_<1>, mpl_::int_<2>, mpl_::int_<3>,
mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na,
mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na,
mpl_::na, mpl_::na, mpl_::na> >::************)’|