Hi, I have class that takes an mpl sequence as its parameter like this: X > And I would like to be able to have the class be used without explicitly declaring the mpl sequence like this: X I know this could be accomplished using variadic template parameters, but I am using an older compiler. I was wondering if there was a macro in boost to do this, such as: template class X { typedef mpl::vector type; }; If a macro is not available, does anyone know how I could write a macro like this? Or what is the default type used for mpl sequences when a type is unspecified? Thanks,Paul