pattern_match_style.c

#include <stdio.h>

#define progn(...) ({ __VA_ARGS__ ;})

#define cond0 (argc < 2)
#define cond1 (argc < 3)
#define cond2 (argc < 4)
#define cond3 (argc < 5)

#define a progn(printf("do something\n"), "a")
#define b ("b", "bb", "bbb", "bbbb")
#define c progn(\
        for(int i = argc; i; --i)\
            printf("i = %d\n", i);\
        "c")
#define d "d"
#define e "e"

int main(int argc, char *argv[])
{
    char *value =
        cond0 ? a :
        cond1 ? b :
        cond2 ? c :
        cond3 ? d :
        e;

    printf("value = %s\n", value);
    return 0;
}