While-Do-While-PoC.cc

#define wdwuc(X,Y) X##Y
#define wdwu(type,condition,counter) if(type) goto wdwuc(dowhile,counter); else while (condition) wdwuc(dowhile,counter):
#define wdw(type,condition) wdwu(type,condition,__COUNTER__)

#include <cstdio>
const char * strings[]{ "1", "2" , "3", 0 };

char * getpacket(){
    static int i = 0;
    if(!strings[i-1])
        i = 0;
    return const_cast<char*>(strings[i++]);
}

void TEST1(char * msg) {
    wdw(msg,msg=getpacket()){
        printf(msg);
    }
    wdw(false,false)
       while(false)
           wdw(false,false) for(;;)
               printf("");
}

int main() {
    TEST1(0); //123
    puts("");
    TEST1(const_cast<char*>("0")); //0123
    return 0;
}