-----Original Message----- From: boost-users-bounces@lists.boost.org [mailto:boost-users- bounces@lists.boost.org] On Behalf Of Daniel James Sent: 06 February 2010 20:51 To: boost-users@lists.boost.org Subject: Re: [Boost-users] generate structs with all combinations of members from a given struct
On 6 February 2010 19:42, Hicham Mouline <hicham@mouline.org> wrote:
Attached now,
The code I posted for getting the subsets before should be faster, here it is adapted for sequences:
Brilliant! Your code is a lot faster. I adapted it to generate the structs. #include <boost/preprocessor.hpp> ///////////////////////////////////////////////////////////////////// // Generates the non-empty subsets of a sequence #define STATEMENT_FROM_PAIR(pair) BOOST_PP_TUPLE_ELEM(2,0,pair) BOOST_PP_TUPLE_ELEM(2,1,pair); #define PRED(r,state) BOOST_PP_SEQ_SIZE(state) #define OP(r,state) BOOST_PP_SEQ_POP_FRONT(state) #define MACRO(r,state) STATEMENT_FROM_PAIR(BOOST_PP_SEQ_HEAD(state)) #define PRED1(r,state) BOOST_PP_SEQ_SIZE(BOOST_PP_TUPLE_ELEM(2,0,state)) #define OP1(r,state) (BOOST_PP_SEQ_POP_FRONT(BOOST_PP_TUPLE_ELEM(2,0,state)),\ BOOST_PP_CAT(\ BOOST_PP_TUPLE_ELEM(2,1,state),\ BOOST_PP_CAT(\ _,\ BOOST_PP_TUPLE_ELEM(2,1,\ BOOST_PP_SEQ_HEAD(BOOST_PP_TUPLE_ELEM(2,0,state))\ )\ )\ )\ ) #define MAKE_STRUCT(r,data,elem) struct BOOST_PP_TUPLE_ELEM(2,1,BOOST_PP_WHILE(PRED1,OP1,(elem,data))) \ { BOOST_PP_FOR(elem, PRED, OP, MACRO) }; #define SUBSETS(struct_name,values) BOOST_PP_SEQ_FOR_EACH(MAKE_STRUCT, struct_name, SUBSETS2(BOOST_PP_SEQ_SIZE(values), BOOST_PP_SEQ_TO_TUPLE(values))) #define SUBSETS2(size, values) BOOST_PP_CAT(SUBSETS_, size) values #define SUBSETS_1(a1) ((a1)) #define SUBSETS_2(a1,a2) SUBSETS_COMBINE(a2, SUBSETS_1(a1)) #define SUBSETS_3(a1,a2,a3) SUBSETS_COMBINE(a3, SUBSETS_2(a1,a2)) #define SUBSETS_4(a1,a2,a3,a4) SUBSETS_COMBINE(a4, SUBSETS_3(a1,a2,a3)) #define SUBSETS_5(a1,a2,a3,a4,a5) SUBSETS_COMBINE(a5, SUBSETS_4(a1,a2,a3,a4)) #define SUBSETS_6(a1,a2,a3,a4,a5,a6) SUBSETS_COMBINE(a6, SUBSETS_5(a1,a2,a3,a4,a5)) #define SUBSETS_7(a1,a2,a3,a4,a5,a6,a7) SUBSETS_COMBINE(a7, SUBSETS_6(a1,a2,a3,a4,a5,a6)) #define SUBSETS_8(a1,a2,a3,a4,a5,a6,a7,a8) SUBSETS_COMBINE(a8, SUBSETS_7(a1,a2,a3,a4,a5,a6,a7)) #define SUBSETS_COMBINE(x, seq_seq) \ seq_seq \ ((x)) \ BOOST_PP_SEQ_FOR_EACH(SUBSETS_COMBINE_IMPL, x, seq_seq) #define SUBSETS_COMBINE_IMPL(r, elem, seq) (seq (elem)) ///////////////////////////////////////////////////////////////////// // Example of use: SUBSETS( params, ((char, field1)) ((float, field2)) ((std::string, field3)) ((int, field4)) ) ///generates this /// struct params_field1 { char field1; }; struct params_field2 { float field2; }; struct params_field1_field2 { char field1; float field2; }; struct params_field3 { std::string field3; }; struct params_field1_field3 { char field1; std::string field3; }; struct params_field2_field3 { float field2; std::string field3; }; struct params_field1_field2_field3 { char field1; float field2; std::string field3; }; struct params_field4 { int field4; }; struct params_field1_field4 { char field1; int field4; }; struct params_field2_field4 { float field2; int field4; }; struct params_field1_field2_field4 { char field1; float field2; int field4; }; struct params_field3_field4 { std::string field3; int field4; }; struct params_field1_field3_field4 { char field1; std::string field3; int field4; }; struct params_field2_field3_field4 { float field2; std::string field3; int field4; }; struct params_field1_field2_field3_field4 { char field1; float field2; std::string field3; int field4; }; How do I use BOOST_PP_ITERATE to get vertical output of the structs, ie, each struct on a different line? Thanks,