[boost] BOOST_NO_RESULT_OF

I want this macro for the parameters library. Currently, result_of uses #if !defined(BOOST_NO_SFINAE) && !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) And otherwise, gives an #error That makes it hard to use portably, because the criteria under which result_of will be supported are not encapsulated, and I couldn't even define it in that file usefully (I'd still get an #error when it isn't supported). Shouldn't there be a generalized way to handle this sort of situation? -- Dave Abrahams Boost Consulting www.boost-consulting.com