This is a simple code generation C macro, so this is simple to be
transcripted into Common Lisp. There are several alternatives to do this.

Either you write the code explicitly in every use occasion or you write a
Common Lisp macro that does the same.

(defmacro cv-seq-elem( seq elem_type index )
  `( Š

But why do you what to do this in Lisp? I would rather write some glue
layer in C and have much simpler calls from Lisp to C.

Good luck.

Frank

Am 02.11.13 16:43 schrieb "Joeish W" unter <joeish80829@yahoo.com>:

>
>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) )