T(mbrtowc(&wc, "\x80", 1, &st), -1, "failed to catch error");
T(mbrtowc(&wc, "\xc0", 1, &st), -1, "failed to catch illegal initial");
T(mbrtowc(&wc, "\x80", 1, &st), -1, "failed to catch error");
T(mbrtowc(&wc, "\xc0", 1, &st), -1, "failed to catch illegal initial");