fn main() {
    const STEP: usize = 1_000_000;
    let mut v = vec![0; 0];
    for i in 0.. {
        for j in 0..STEP {
            v.push(j);
        }
        println!("{}: {} MB", i, std::mem::size_of_val(&v[..]) / 1_000_000);
    }
}