rust_testxyz123 0.1.0

struct MyIter {
    current: i32,
    max: i32,
}

impl MyIter {
    fn new(max: i32) -> MyIter {
        MyIter {
            current: 0,
            max,
        }
    }
}

impl Iterator for MyIter {
    type Item = i32;

    fn next(&mut self) -> Option<Self::Item> {
        if self.current >= self.max {
            return None;
        }

        let v = self.current;
        self.current += 1;
        Some(v)
    }
}

fn main() {
    let v = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
    let n: i32 = v.iter().sum();
    println!("{}", n);

    println!("{:?}", v.iter().map(|&x| x + 1).collect::<Vec<_>>());

    let n: i32 = MyIter::new(10).zip(MyIter::new(100).skip(10))
        .map(|(x, y)| x * y)
        .filter(|x| x % 3 == 0)
        .sum();
    println!("{}", n);
}