Hello. I’m using CodeGear compiler with Boost 1.39 and Boost 1.45. In both of them I have found an error in mpl\base.hpp line 25 (typedef typename T::base type;) [BCC32 Error] base.hpp(25): E2404 Dependent type qualifier 'na' has no member type named 'base' The code is: namespace boost { namespace mpl { template< typename BOOST_MPL_AUX_NA_PARAM(T) // find in mpl\aux_\na_spec.hpp, line 152: #define BOOST_MPL_AUX_NA_PARAM(param) param = na > struct base { typedef typename T::base type; // <------- ERRORRR BOOST_MPL_AUX_LAMBDA_SUPPORT(1,base,(T)) }; BOOST_MPL_AUX_NA_SPEC(1, base) }} Help will be appreciated. Thanks!