a UCS-4 encoded string
location to store number of bytes read, or NULL. If an error occurs then the index of the invalid input is stored here. [allow-none]
a pointer to a newly allocated UTF-16 string. This value must be freed with g_free(). If an error occurs, NULL will be returned and error set.
GException on failure.
Convert a string from UCS-4 to UTF-16. A 0 character will be added to the result after the converted text.