[boost] BOOST_PP_ENUM_PARAMS can't be nested inside BOOST_PP_IF?

Hi, The following code: #include <boost/preprocessor/control/if.hpp> #include <boost/preprocessor/enum_params.hpp> BOOST_PP_ENUM_PARAMS(3, p) BOOST_PP_IF(1, BOOST_PP_ENUM_PARAMS(3, p), blah) results in the following text (vc71, main CVS): p0 , p1 , p2 p0 and a warning: to many parameters for BOOST_PP_IIF_1. What's wrong? Regards, Arkadiy