#ifndef MACRO_UTILS_H #define MACRO_UTILS_H #define CALL(m, ...) m(__VA_ARGS__) #define EMPTY() #define EVAL(...) EVAL32(__VA_ARGS__) #define EVAL1024(...) EVAL512(EVAL512(__VA_ARGS__)) #define EVAL512(...) EVAL256(EVAL256(__VA_ARGS__)) #define EVAL256(...) EVAL128(EVAL128(__VA_ARGS__)) #define EVAL128(...) EVAL64(EVAL64(__VA_ARGS__)) #define EVAL64(...) EVAL32(EVAL32(__VA_ARGS__)) #define EVAL32(...) EVAL16(EVAL16(__VA_ARGS__)) #define EVAL16(...) EVAL8(EVAL8(__VA_ARGS__)) #define EVAL8(...) EVAL4(EVAL4(__VA_ARGS__)) #define EVAL4(...) EVAL2(EVAL2(__VA_ARGS__)) #define EVAL2(...) EVAL1(EVAL1(__VA_ARGS__)) #define EVAL1(...) __VA_ARGS__ #define EVAL0(...) #define SND(a, b, ...) b #define FST(a, ...) a #define CAT(a, b) a##b #define STR(a) #a #define PROBE() ~, 1 #define IS_PROBE(...) SND(__VA_ARGS__, 0) // _FAST_NOT(0) -> 1 _FAST_NOT(1) -> 0 #define _FAST_NOT(x) CAT(_FAST_NOT_, x)() #define _FAST_NOT_0() 1 #define _FAST_NOT_1() 0 // NOT(0) -> 1 NOT(...) -> 0 #define NOT(x) IS_PROBE(CAT(_NOT_, x)) #define _NOT_0 PROBE() // BOOL(0) -> 0 BOOL(...) -> 1 #define BOOL(x) _FAST_NOT(NOT(x)) // Same as EVAL1 but different meaning #define KEEP(...) __VA_ARGS__ // Drop / Delete the arguments #define DROP(...) #define IF_ELSE(c) FAST_IF_ELSE(BOOL(c)) // IF_ELSE if c is know to be 0 or 1 #define FAST_IF_ELSE(c) CAT(_IF_ELSE_, c) #define _IF_ELSE_0(...) KEEP #define _IF_ELSE_1(...) __VA_ARGS__ DROP #define HAS_ARGS(...) BOOL(FST(_HAS_ARGS_ __VA_ARGS__)()) #define _HAS_ARGS_() 0 #define IF_ELSE_ARGS(...) FAST_IF_ELSE(HAS_ARGS(__VA_ARGS__)) #define DEFER1(x) x EMPTY() #define DEFER2(x) x EMPTY EMPTY()() #define DEFER3(x) x EMPTY EMPTY EMPTY()()() #define DEFER4(x) x EMPTY EMPTY EMPTY EMPTY()()()() #define DEFER5(x) x EMPTY EMPTY EMPTY EMPTY EMPTY()()()()() #define MAP(m, fst, ...) m(fst) __VA_OPT__(DEFER1(_MAP)()(DEFER1(m), __VA_ARGS__)) #define _MAP() MAP #define REVERSE(...) IF_ELSE_ARGS(__VA_ARGS__)(EVAL(_REVERSE(__VA_ARGS__)))() #define _REVERSE(a, ...) __VA_OPT__(DEFER1(__REVERSE)()(__VA_ARGS__), ) a #define __REVERSE() _REVERSE #endif