int cunescape(const char *s, UnescapeFlags flags, char **ret);
int cunescape_length(const char *s, size_t length, UnescapeFlags flags, char **ret);
int cunescape_length_with_prefix(const char *s, size_t length, const char *prefix, UnescapeFlags flags, char **ret);
int cunescape(const char *s, UnescapeFlags flags, char **ret);
int cunescape_length(const char *s, size_t length, UnescapeFlags flags, char **ret);
int cunescape_length_with_prefix(const char *s, size_t length, const char *prefix, UnescapeFlags flags, char **ret);