struct calculate_args { int x, y; enum {add=0, sub} operator; }; int calculate_func(struct calculate_args args) { if (args.operator == add) return args.x + args.y; else return args.x - args.y; } #define calculate(...) calculate_func((struct calculate_args){__VA_ARGS__})
calculate(1, 3); // 4 calculate(8, 3, .operator=sub); // 5 calculate(.operator=sub, .y=7); // -7
#include <stdio.h> #define CONCAT2(a, b) a##b #define CONCAT(a, b) CONCAT2(a, b) #define COUNT_ARGS2(a0, a1, a2, a3, a4, a5, a6, a7, a8, N, ...) N #define COUNT_ARGS(...) COUNT_ARGS2(__VA_ARGS__, 9, 8, 7, 6, 5, 4, 3, 2, 1) #define foo(...) CONCAT(foo_, COUNT_ARGS(__VA_ARGS__))(__VA_ARGS__) void foo_1(const char *a){ printf("one arg: %s\n", a); } void foo_2(int a, int b){ printf("two args: %i and %i\n", a, b); } int main(){ foo("asdf"); foo(314159, 271828); }
I just wanted to post it, but you already did. :-)
