Patterns

https://doc.rust-lang.org/book/patterns.html

構造体のmatchもできるのが便利。

    struct Point {
        x: i32,
        y: i32,
    }

    let origin = Point { x: 2, y: 4 };
    match origin {
        Point { x, y } => println!("({},{})", x, y),
    }
    // -> (2,4)
    match origin {
        Point { x, .. } => println!("x is {}", x),
    }
    // -> x is 2
    match origin {
        Point { y, .. } => println!("y is {}", y),
    }
    // -> y is 4