I have these C bindings for the C++ vector which I have wrapped in CFFI. I know how to create vectors with std_carrayTovector and convert the data back to a int pointer with std_vectorToCArray so that I can retrieve data from it in Lisp using the CFFI function MEM-AREF. I have correct defcfuns written for the below . My question is how to I convert the output of my defcfun for std_vectorToCArray at the bottom of the page, into a Lisp vector eg #(1 2 3) and make it a 0(1) operation/all data copied at the same time.

vector_int* std_carrayTovector(int* a, size_t len) {
    vector<int>* v = new vector<int>;
    for(size_t i = 0; i < len; i++) 
        v->push_back(a[i]);
    return v;
}

int* std_vectorToCArray(vector_int* s) {
    return s->data();
}


(defcfun ("std_vectori_to_carray" %vector-int-to-c-array) :pointer 
  (s (:pointer vector-int)))