Have macro 'return' a value

Question

I\'m using a macro and I think it works fine -

#define CStrNullLastNL(str) {char* nl=strrchr(str,\'\\n\'); if(nl){*nl=0;}}

So it works to zero out the last

Answer 1

to return value from macro:

bool my_function(int a) {
    if (a > 100)return true;
    return false;
}
bool val = my_function(200);

#define my_macro(ret_val,a){\
    if(a > 100 ) ret_val = true;\
    ret_val = false;\
}
bool val; my_macro(val, 200);