Question

I want to invoke multi-line macro in circulation to break/continue it.

If I use “do{…}while(0)” in multi-line macro definition, break/continue is only effect on “do {…}while(0)”, not the circulation who invoke this macro. So I consider using “if(1){…}” in multi-macro definition.

#define EXIT_CIRCULATION() \
        if(1){ \
           break; \
        }

void func(){
    while(1){
       ...
       EXIT_CIRCULATION();
       ...
    }
}

But I doubt wheather it is a good way to use “if(1){…}” in macro definition, because I can not find any example in internet.

Thanks!

Answer 1

if you code something like

 if (somecondition)
    EXIT_CIRCULATION();
 else
    break;

then the expansion of your macro won’t behave as you intuitively expect. The else would apply to your if (1) and will never happen.