fn main () {
    /*
     * int *x = malloc(sizeof(int));
     * or
     * int *x = new int;
     */
    let heap_number = Box::new(100);
    println!("heap_number = {}", heap_number);

    let heap_array = Box::new([1, 2, 3, 4, 5]);
    for n in heap_array.iter() {
        println!("heap_array = {}", n);
    }
}