Demonstrates filling in a u32vector from an FFI function returning a pointer in Chicken Scheme

output

(4 9 15)

test.h

static const int TEST_SIZE = 3;
static unsigned int testArray[TEST_SIZE] = {4, 9, 15};

static unsigned int* testFunc()
{
        return testArray;
}

test.scm

(use srfi-4)

(foreign-declare "#include \\"test.h\\"")

(define test-size 3)

(define c-test-func
  (foreign-lambda* int ((nonnull-u32vector vector_out))
                   "unsigned int* array_from_func = testFunc();
                    memcpy(vector_out, array_from_func, TEST_SIZE * sizeof(unsigned int));
                    C_return(TEST_SIZE);"))

(define (test-func)
  (let* ((buffer    (make-u32vector test-size)))
    (c-test-func buffer)
    (u32vector->list buffer)))

(write (test-func))