ViewCount Example

main.rs

mod domain {
    pub struct ViewCount {
        value: usize,
    }
    impl ViewCount {
        pub fn new(value: usize) -> Self {
            Self { value }
        }
        pub fn value(&self) -> usize {
            self.value
        }
    }
}
use domain::*;
fn main() {
    let viewcounts = vec![ViewCount::new(3), ViewCount::new(5), ViewCount::new(7)];
    let sum: usize = Iterator::sum(viewcounts.iter().map(|vc| vc.value()));
    println!("total views: {}", sum);
}