I'm trying to apply a transformation to an mpl::string, but can't get it to compile. I'm using MS VC++2010 and Boost 1.43.0. The code:
#include <boost/mpl/string.hpp>
#include <boost/mpl/vector_c.hpp>
#include <boost/mpl/transform.hpp>
#include <boost/mpl/plus.hpp>
#include <boost/mpl/arithmetic.hpp>
using namespace boost;
int main() {
// this compiles OK
typedef mpl::vector_c<int, 'abcd', 'efgh'> numbers;
typedef mpl::transform<numbers, mpl::plus<mpl::_1, mpl::int_<1> > >::type result_numbers;
// this doesn't (error C2039: 'value' : is not a member of 'boost::mpl::has_push_back_arg')
typedef mpl::string<'abcd', 'efgh'> chars;
typedef mpl::transform<chars, mpl::plus<mpl::_1, mpl::int_<1> > >::type result_chars;
}