308 struct reference_argument {  struct
309   typedef typename detail::parameter_traits_<T, T&>::type type; 
313 struct reference_argument<T&> {  struct
314   typedef typename detail::generate_error<T&>::references_not_allowed type; 
318 struct reference_argument<lambda_functor<Arg> > {  struct
319   typedef lambda_functor<Arg> type;
323 struct reference_argument<const lambda_functor<Arg> > {  struct
324   typedef lambda_functor<Arg> type;
329 struct reference_argument<volatile lambda_functor<Arg> > {  struct
330   typedef lambda_functor<Arg> type;
334 struct reference_argument<const volatile lambda_functor<Arg> > {  struct
335   typedef lambda_functor<Arg> type;
339 struct reference_argument<void> {  struct
340   typedef void type;