Re: [Boost-users] [boost-users][bind, lambda, ...] binding unused actual parameter

     template<class U> R operator()(U & u) const      { -        BOOST_MEM_FN_RETURN call(u, &u); +        BOOST_MEM_FN_RETURN call(u, false ? &u : 0);      }

 #ifdef BOOST_MEM_FN_ENABLE_CONST_OVERLOADS

     template<class U> R operator()(U const & u) const      { -        BOOST_MEM_FN_RETURN call(u, &u); +        BOOST_MEM_FN_RETURN call(u, false ? &u : 0);      }

 #endif

Wow, very nice idea! But if you intend to commit this patch to the trunk, please note that there're 25 more places in this file where the above change should be done :).