a UTF-8 encoded string
the maximum length of str to use, in bytes. If len < 0, then the string is nul-terminated.
location to store the number of characters in the result, or NULL.
a pointer to a newly allocated UCS-4 string. This value must be freed with g_free().
Convert a string from UTF-8 to a 32-bit fixed width representation as UCS-4, assuming valid UTF-8 input. This function is roughly twice as fast as g_utf8_to_ucs4() but does no error checking on the input. A trailing 0 character will be added to the string after the converted text.