int utf8_strncasecmp (const char *, size_t, const char *, size_t);
int utf8_strverscasecmp (const char *, const char *);
char *utf8_to_upper (const char *);
char *utf8_to_lower (const char *);
int utf8_strncasecmp (const char *, size_t, const char *, size_t);
int utf8_strverscasecmp (const char *, const char *);
char *utf8_to_upper (const char *);
char *utf8_to_lower (const char *);