Hi during my implementation of unique_ptr I noticed that boost::forward doesn't play nicely with lvalue ref types. int a; int &b = a; int &c = std::forward<int&>(b); // compiles fine int &d = boost::forward<int&>(b); // compiler error I did a little playing around with the declarations of forward and I managed to get this to work: // if T is not a lvalue ref and movable template <class T> inline typename ::boost::move_detail::enable_if_c < enable_move_utility_emulation<T>::value && ::boost::move_detail::is_rv<T>::value && !::boost::move_detail::is_lvalue_reference<T>::value, const T &>::type forward(typename ::boost::move_detail::identity<T>::type &x) BOOST_NOEXCEPT { return const_cast<T&>(x); } // if T is not a lvalue ref and not movable template <class T> inline typename ::boost::move_detail::enable_if_c < enable_move_utility_emulation<T>::value && !::boost::move_detail::is_rv<T>::value && !::boost::move_detail::is_lvalue_reference<T>::value, const T &>::type forward(const typename ::boost::move_detail::identity<T>::type &x) BOOST_NOEXCEPT { return x; } // if T is a lvalue ref template <class T> inline typename ::boost::move_detail::enable_if_c < ::boost::move_detail::is_lvalue_reference<T>::value , T>::type forward(T x) BOOST_NOEXCEPT { return x; } Basically, this forces all calls to forward<A&> to simply return the lvalue ref (const-ness is maintained, I think), otherwise it does whatever boost::forward did before. As far as I can tell, this doesn't break boost::forward, and it enables it to properly handle taking lvalue refs. Am I right in my assumptions? Are there any cases where this would fail to produce standard-compliant/desired results?