Question

Before I move on – is there already a type list implementation either in boost or a small implementation that uses it? I haven’t found anything useful so far.

I’m attempting to use boost pp to generate list classes of various sizes:

#define BOOST_PP_LOCAL_MACRO(n) \
    template< BOOST_PP_ENUM_TRAILING_PARAMS(n, class t) >   /*error C2913: explicit specialization; 'typelist1' is not a specialization of a class template*/ \
struct typelist##n \
{ \
    typedef t##n e##n; /*I want n of these*/ \
};

#define Type_At(list, element) list::e##element

#define BOOST_PP_LOCAL_LIMITS (1, 5)

#include BOOST_PP_LOCAL_ITERATE()

See the comments in the code of the issues. Is this a decent way to go about making a typelist? It seems…. dirty. I only just heard about the concept of a typelist, so I’m not familiar with different flavors.

Solution:

#define BOOST_MPL_LIMIT_VECTOR_SIZE  50
#include <boost/mpl/vector.hpp>
#include <boost/mpl/at.hpp>

typedef boost::mpl::vector<int, float, double, long, short> vecType;
boost::mpl::at_c<vecType, 3>::type hi = 3;

Answer 1

Maybe you could try boost::mpl::vector. _{(I can’t quite see what were you trying to do).}

If you could use c++11, making a typelist is much easier with variadic templates (meaning no nasty preprocessor stuff).