the function I'm trying to wrap is here CV_INLINE  CvPoint  cvPoint( int x, int y ) {     CvPoint p;     p.x = x;     p.y = y;     return p; } and here is the related struct typedef struct CvPoint {     int x;     int y; } CvPoint; I wrap it like this like I normally  do ; this is how swig wrapped the defcstruct (cffi:defcstruct cv-point     (x :int)     (y :int)) ;; CvPoint cvPoint(int x, int y) (cffi:defcfun ("cvPoint" pointy) (:struct cv-point)   "constructs CvPoint structure."   (x :int)   (y :int)) the wrapper i made runs at the repl but when i call the function i get error CL-OPENCV> (point 7 7) The value NIL is not of type SB-SYS:SYSTEM-AREA-POINTER.    [Condition of type TYPE-ERROR] Backtrace:   0: (CFFI::CALL #.(SB-SYS:INT-SAP #X7FFFE0000E10) NIL #.(SB-SYS:INT-SAP #X7FFFE5427FD0) #.(SB-SYS:INT-SAP #X7FFFE5427FD8))       Locals:         SB-DEBUG::ARG-0 = #.(SB-SYS:INT-SAP #X7FFFE0000E10)         SB-DEBUG::ARG-1 = NIL         SB-DEBUG::ARG-2 = #.(SB-SYS:INT-SAP #X7FFFE5427FD0)         SB-DEBUG::ARG-3 = #.(SB-SYS:INT-SAP #X7FFFE5427FD8) in the backtrace it appears to be linking 4 parameters and i  think its because of this CV_INLINE  CvPoint  cvPoint( int x, int y ) {     CvPoint p;     p.x = x;     p.y = y;     return p; } because their are 4 items in the CV_INLINE   I was hoping someone could help me get by this error message