Hi, I guess this is more of a regular preprocessor question than a Boost.Preprocessor specific one, but: Shouldn't it be possible to concat tokens starting with (or solely consisting of) a '-'? The example at the end of this posting yields the errors: error: pasting "-" and "debug" does not give a valid preprocessing token error: pasting "foo" and "-" does not give a valid preprocessing token --- #include <boost/preprocessor/cat.hpp> #include <boost/preprocessor/stringize.hpp> #include <iostream> #define MODULE foo #define VARIANT debug #define NAME BOOST_PP_CAT(MODULE, BOOST_PP_CAT(-, VARIANT)) void foo() { std::cout << "The name is: " << BOOST_PP_STRINGIZE(NAME) << '\n'; } --- Any workaround? I'm using Boost from cvs at RC_1_34_0 and g++ 4.0.2 under OpenSuse 10. / Johan