Hello all, Is there a reason why `BOOST_PP_IS_EMPTY()` is not part of Boost.Preprocessor reference documentation? 1) I think this macro is part of the library public API because it is in <boost/preprocessor/facilities/is_empty.hpp> (outside the "detail/" directory and same location as `BOOST_PP_EMPTY` which is documented). 2) Is it OK to use `PP_IS_EMPTY()` to check if a macro expansion is actually empty or not? For example: #include <boost/preprocessor/facilities/empty.hpp> #include <boost/preprocessor/facilities/is_empty.hpp> #define X /* expand to nothing */ #define Y BOOST_PP_EMPTY #define Z a b c BOOST_PP_EMPTY BOOST_PP_IS_EMPTY(X) // expand to 1 BOOST_PP_IS_EMPTY(Y()) // expand to 1 BOOST_PP_IS_EMPTY(Y) // expand to 0 BOOST_PP_IS_EMPTY(Z()) // expand to 0 Thank you for the clarification. -- Lorenzo