@param s Pointer to the tag data, as returned by bam_aux_get().
@param idx 0-based Index into the array
@return The idx'th value, or 0 on error.
If the array is not an integer type, errno is set to EINVAL. If idx
is greater than or equal to the value returned by bam_auxB_len(s),
errno is set to ERANGE. In both cases, 0 will be returned.
@param s Pointer to the tag data, as returned by bam_aux_get(). @param idx 0-based Index into the array @return The idx'th value, or 0 on error. If the array is not an integer type, errno is set to EINVAL. If idx is greater than or equal to the value returned by bam_auxB_len(s), errno is set to ERANGE. In both cases, 0 will be returned.