r = sd_journal_add_match(...);
if (r < 0) {
    //some error
}

r = sd_journal_add_match(...);
r |= sd_journal_add_match(...);
...

(void) ( ... );

r |= sd_journal_add_match(...);

(r = sd_journal_add_match(j, "_UID=0", 0)) ||
(r = sd_journal_add_match(j, m2, 0)) ||

(void)printf("Hello World");

if (printf("Hello World") < 0) {
    // do some error handling here
}

printf("Hello World");

f() || g(); // better (void)(f() || g());