e r wrote:

e r wrote:

...

hi,

here's the problem i have: struct my{ template<typename UInt> struct apply{ typedef mpl::int_UInt::value type; }; };

template struct id_range{ typedef mpl::transform< mpl::range_c , my , mpl::back_inserter< mpl::vector<> > >::type type;

/home/er/cpp/boost/random/mcmc/id_range.hpp|32|error: type ‘boost::mpl::transform, boost::random::mcmc::<unnamed>::my, boost::mpl::back_inserter >, mpl_::na>’ is not derived from type ‘boost::random::mcmc::id_range’|

however, for example, this --instead-- compiles fine:

struct id_range{ typedef mpl::transform< mpl::range_c , 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, boost::mpl::vector, 0>, 0>, boost::mpl::vector, 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> >::************)’|

In the first post: there's a typename missing, which solves the problem.

Steven Watanabe wrote:

AMDG

e r wrote:

...

...

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,

<snip>

Two boost::mpl::vectors that contain the same elements are not guaranteed to be the same type. If you boost::mpl::equal, it ought to work.

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

In Christ, Steven Watanabe

Got it, thanks. And also, I should add that range_c represent [1,3) ,not [1,3].