Hi, Both implementation of futures used at least two call to new, one for T and one for the common class between the future and the promise. Le me kno if I have missed something, do we really need the shared_ptr<T>? can't we use the future_object/future_impl class to store directly T. On the Anthony implementation we see already the intent to use allocators for the promise construction // template <class Allocator> explicit promise(Allocator a); but not for the new T in template<typename T> struct future_traits { typedef boost::scoped_ptr<T> storage_type; // ... static void init(storage_type& storage,source_reference_type t){storage.reset(new T(t));} //... } Anthony, do you plan to use the same allocator for T? Braddock, do you plan to use allocators? Best _____________________ Vicente Juan Botet Escriba