[boost] function_traits

Hi, I find the interface: function_traits<F>::arity function_traits<F>::result_type function_traits<F>::argN_type (especially the last) awkward in TMP code. In the interest of not having metafunction blobs, I'd suggest the interface: function_arity<F>::value function_result<F>::type function_arg_c<N, F>::type function_arg<mpl::int_<N>, F>::type In particular, I need the function_arg(_c) metafunctions. It is very awkward to get the Nth function argument, given a constant N. Thoughts? Cheers, -- Joel de Guzman http://www.boost-consulting.com http://spirit.sf.net