Another simple ffi example

numbers.c

#include <stdint.h>
#include <stdlib.h>

void
get_numbers(int64_t *numbers, uint64_t size)
{
    for(int i=0; i < size; i++) {
        numbers[i] = rand();
    }
}

numbers.rkt

#lang racket/base

(require ffi/unsafe
         ffi/unsafe/define)

(define-ffi-definer define-numbers (ffi-lib "numbers"))

(define-numbers get_numbers
  (_fun [number-vec : (_vector o _int64 size)]
        [size : _uint64]
        -> _void
        -> number-vec))

(get_numbers 10)