How to repeat code using __VA_ARGS_

I want to create a macro in C that does the following.

#define SETUP_BULK(...) \
SETUP_HELPER(__VA_ARG__) \ // repeat this for all __VA_ARGS__

Is this possible? I looked up other questions on iterating __VA_ARGS__ but to no avail.

I can't use anything other than macros, or that would defeat the purpose of my goal - to dynamically setup structures with my custom JSON parser.

Eg:

SETUP_BULK(Struct_A, Struct_B, Struct_C)

would turn into

SETUP_HELPER(Struct_A);
SETUP_HELPER(Struct_B);
SETUP_HELPER(Struct_C);

CodePudding user response：

If you insist on doing this at the level of macros, the simplest solution is to use Boost.Preprocessor:

#include <boost/preprocessor/variadic/to_seq.hpp>
#include <boost/preprocessor/seq/for_each.hpp>

// ...

#define SETUP_HELPER2(r, data, elem) SETUP_HELPER(elem)

#define SETUP_BULK(...) \
BOOST_PP_SEQ_FOR_EACH(SETUP_HELPER2, _, BOOST_PP_VARIADIC_TO_SEQ(__VA_ARGS__))

Demo