Re: [Boost-users] class composition

Subject: Re: [Boost-users] class composition
From: Joel Falcou (joel.falcou_at_[hidden])
Date: 2009-01-13 13:17:19

Hicham Mouline a écrit :
> hello,
> There is an example listed in "C++ template metaprogramming" to generate a class with its members from an mpl sequence:
>
> template <typename T>
> struct wrap { typedef T value; };
>
> typedef mpl::vector< type1, type2, type3 > member_types;
> mpl::inherit_linearly< member_types, mpl::inherit< wrap<_2>, _1 > >::type  generated;
>
>
> but then, the generated class did not look like this:
>
> class C {
>   type1 t1;
>   type2 t2;
>   type3 t3;
> };
>
>
> Can one do that with BOOST_PP and sequences from preprocessor libs instead?
>   
Yes, something like :

#define MEMBER(z,n,text) BOOST_PP_CAT(text,n)  BOOST_PP_CAT(t,n);

class C
{
   BOOST_PP_ENUM_(3,MEMBER,type)
};

A more generic version can be done if you pass a tuple of symbol as ENUM 
data

-- 
___________________________________________
Joel Falcou - Assistant Professor
PARALL Team - LRI - Universite Paris Sud XI
Tel : [phone]