;; double each element of v (with length n) in place

(define double!

(c-lambda (scheme-object int) ; the vector and it's length

void

"//extract array from scheme object

___U16* v = ___CAST(___U16*, ___BODY_AS(___arg1, ___tSUBTYPED));

// perform the C operations

int i;

for (i=0; i<___arg2; i+=1) {

v[i] += v[i];

}"))

(define *v* (u16vector 0 1 2 3 4 5))

(display *v*)

(newline)

(double! *v* (u16vector-length *v*))

(display *v*)