C's switch() with only macros | http://codepad.org/4z67amon

evil.c

#include "stddef.h"
#include "stdio.h"
#include "stdbool.h"

#define BEGIN_SWITCH(expr) { int _val = expr; bool chosen = false; {
#define END_SWITCH() } } _switch_end: NULL;
#define CASE(val) } if (chosen || _val == val) { chosen = true;
#define BREAK() goto _switch_end;

int main () {
    BEGIN_SWITCH(2)
        CASE(1)
            printf("hello, world\n");
        CASE(2)
            printf("hello, universe\n");
        CASE(3)
            printf("hello, fallthrough\n");
            BREAK()
        CASE(4)
            printf("hello, nobody\n");
    END_SWITCH()
}