both for that type. A trait class is never passed as a template parameter; it's name is ubiquitous.
Whoops, can't agree there. The boost type traits are passed as template parameters all the time:
mpl::apply_if< is_pointer<X>, remove_pointer<X>, add_reference<X> >
What he meant, I think, is "never passed as a template parameter together with primary type"
A traits class never has state.
Policy - A class template passed to other templates for the purpose of providing a named grouping of metainformation,
I think a Policy might be a non-templated class.
True.
I think your definitions are mostly on target, but I think where you go wrong is that traits/policies has less to do with how a template is defined than how it's used.
Could you please rephrase. It's a bit unclear. Gennadiy.