fn test(value: i32) {
    dbg!(value);
}

#[derive(Debug)]
struct Foo {
    inner: String,
}

impl From<Foo> for i32 {
    fn from(f: Foo) -> i32 {
        f.inner.parse().unwrap()
    }
}

// Defined automatically:
//
// impl Into<i32> for Foo {
//     fn into(self) -> i32 {
//         self.inner.parse().unwrap()
//     }
// }

fn main() {
    let foo = Foo { inner: "500".to_owned() };
    test(foo.into());

    let foo = Foo { inner: "500".to_owned() };
    test(Into::<i32>::into(foo));
}