I'm trying to wrap the GET_SEQ_ELEM  macro below can some one give me clues or example how i would go about this easily

with a cffi function like defcfun...If there is no clear way i definately propose an addendum to cffi for wrapping macros

#define  CV_SEQ_ELEM( seq, elem_type, index )                    \
/* assert gives some guarantee that <seq> parameter is valid */  \
(   assert(sizeof((seq)->first[0]) == sizeof(CvSeqBlock) &&      \
    (seq)->elem_size == sizeof(elem_type)),                      \
    (elem_type*)((seq)->first && (unsigned)index <               \
    (unsigned)((seq)->first->count) ?                            \
    (seq)->first->data + (index) * sizeof(elem_type) :           \
    cvGetSeqElem( (CvSeq*)(seq), (index) )))
#define CV_GET_SEQ_ELEM( elem_type, seq, index ) CV_SEQ_ELEM( (seq), elem_type, (index) )