main.rs

#[inline(three_and_five)]
fn three_and_five() -> usize {
    (1..1000).filter(|x| { x % 3 == 0 || x % 5 == 0 }).sum()
}

#[inline(fib)]
fn fib() -> usize {
    struct Fib {
        curr : usize,
        next : usize,
    };
    let fib = Fib { curr : 0, next : 1};

    impl Iterator for Fib {
        type Item = usize;
        fn next(&mut self) -> Option<usize> {
            let new_next = self.curr + self.next;
            self.curr = self.next;
            self.next = new_next;
            Some(self.curr)
        }
    };

    fib.take_while(|x| x < &4000000usize ).filter(|x| x % 2 == 0).fold(0, |x,y|x+y)
}

fn main() {
    println!("problem 1: {}", three_and_five());
    println!("problem 2: {}", fib());
}