Is there a reason why Boost.Preprocessor does not have many (any?) utilities for variadic macros? I have implemented a FOREACH( MACRO, ... ) that results in the following expansion MACRO(ARG1) MACRO(ARG2) ... Implemented as such: #define FOREACH_ARRAY( ... ) (PP_NARG(__VA_ARGS__) , ( __VA_ARGS__ ) ) #define FOREACH( A, ... ) BOOST_PP_REPEAT( PP_NARG(__VA_ARGS__), A, FOREACH_ARRAY(__VA_ARGS__) ) #define CASE(z,n,data) case BOOST_PP_ARRAY_ELEM( n, data ): FOREACH( CASE, a, b, c, d, e) case a: case b: case c: case d: case e: Depends upon this macro: #define PP_NARG(...) \ PP_NARG_(__VA_ARGS__,PP_RSEQ_N()) #define PP_NARG_(...) \ PP_ARG_N(__VA_ARGS__) #define PP_ARG_N( \ _1, _2, _3, _4, _5, _6, _7, _8, _9,_10, \ _11,_12,_13,_14,_15,_16,_17,_18,_19,_20, \ _21,_22,_23,_24,_25,_26,_27,_28,_29,_30, \ _31,_32,_33,_34,_35,_36,_37,_38,_39,_40, \ _41,_42,_43,_44,_45,_46,_47,_48,_49,_50, \ _51,_52,_53,_54,_55,_56,_57,_58,_59,_60, \ _61,_62,_63,N,...) N #define PP_RSEQ_N() \ 63,62,61,60, \ 59,58,57,56,55,54,53,52,51,50, \ 49,48,47,46,45,44,43,42,41,40, \ 39,38,37,36,35,34,33,32,31,30, \ 29,28,27,26,25,24,23,22,21,20, \ 19,18,17,16,15,14,13,12,11,10, \ 9,8,7,6,5,4,3,2,1,0