boost::mpl::for_each without instantiating

Question

Taking the following example, I wonder whether there is an alternative to boost::mpl::for_each, which does call a Functor without any arguments.

Answer 1

Use boost::type and mpl::_ to create an MPL lambda that transforms each type in the list before instantiating the elements and calling the function, like this:

mpl::for_each >(Registrator());

Registrator should look something like this:

struct Registrator
{
  template
  void operator()(boost::type) const
  {
      RegisterInFactory dummy(T::name());
  }
};

Hope that helps.