the string to convert
conversion descriptor from g_iconv_open()
location to store the number of bytes in the input string that were successfully converted, or NULL. Even if the conversion was successful, this may be less than len if there were partial characters at the end of the input. If the error G_CONVERT_ERROR_ILLEGAL_SEQUENCE occurs, the value stored will the byte offset after the last valid input sequence.
If the conversion was successful, a newly allocated nul-terminated string, which must be freed with g_free(). Otherwise NULL and error will be set.
GException on failure.
Converts a string from one character set to another. Note that you should use g_iconv() for streaming conversions[3].