here is the way CvMemStorage is defined typedef struct CvMemStorage { int signature; CvMemBlock* bottom; /* First allocated block. */ CvMemBlock* top; /* Current memory block - top of the stack. */ struct CvMemStorage* parent; /* We get new blocks from parent as needed. */ int block_size; /* Block size. */ int free_space; /* Remaining free space in current block. */ } CvMemStorage; bu i get unknown CFFI type: (:STRUCT CV-MEM-STORAGE). [Condition of type SIMPLE-ERROR] when i wrap like this....i know lisp is known for recursion how do i bypass this (defcstruct cv-mem-storage (signature :int) (bottom (:pointer (:struct cv-mem-block))) (top (:pointer (:struct cv-mem-block))) (parent (:pointer (:struct cv-mem-storage))) (block-size :int) (free-space :int))