Daniel James wrote:
Sorry about all these tests and thanks for your patience. Here's another one which uses a slightly different method that I think should will better:
Actually, can you also preprocess this test? I really think this one will work. Which probably means it won't. #include <boost/preprocessor/seq/elem.hpp> #include <boost/preprocessor/punctuation/paren.hpp> #define IS_NULLARY(x) BOOST_PP_SEQ_ELEM(1, (IS_NULLARY_C x)(0)) #define IS_NULLARY_C() ~ BOOST_PP_RPAREN() (1) BOOST_PP_LPAREN() ~ IS_NULLARY(()) // 1 IS_NULLARY(()abc) // 1 IS_NULLARY(+) // 0 IS_NULLARY(xyz) // 0 #define IS_UNARY(x) IS_NULLARY(IS_UNARY_C x) #define IS_UNARY_C(a) () IS_UNARY((a)) // 1 IS_UNARY((a)abc) // 1 IS_UNARY(+) // 0 IS_UNARY(xyz) // 0