a UCS-4 encoded string
the maximum length (number of characters) of @str to use. If @len < 0, then the string is nul-terminated.
location to store number of characters read, or %NULL.
location to store number of bytes written or %NULL. The value here stored does not include the trailing 0 byte.
a pointer to a newly allocated UTF-8 string. This value must be freed with g_free(). If an error occurs, %NULL will be returned and @error set. In that case, @items_read will be set to the position of the first invalid input character.
GException on failure.
Convert a string from a 32-bit fixed width representation as UCS-4. to UTF-8. The result will be terminated with a 0 byte.