Rust結構

有三種類型的結構(“structs”)，可以使用被struct 關鍵字創建 :

• 元組結構，這是命名為元組的基礎。
• 典型的 C 結構
• 單元結構，這是無字段，對泛型有用。

// A unit struct
struct Nil;

// A tuple struct
struct Pair(i32, f64);

// A struct with two fields
struct Point {
    x: f64,
    y: f64,
}

// Structs can be reused as fields of another struct
#[allow(dead_code)]
struct Rectangle {
    p1: Point,
    p2: Point,
}

fn main() {
    // Instantiate a `Point`
    let point: Point = Point { x: 0.3, y: 0.4 };

    // Access the fields of the point
    println!("point coordinates: ({}, {})", point.x, point.y);

    // Destructure the point using a `let` binding
    let Point { x: my_x, y: my_y } = point;

    let _rectangle = Rectangle {
        // struct instantiation is an expression too
        p1: Point { x: my_y, y: my_x },
        p2: point,
    };

    // Instantiate a unit struct
    let _nil = Nil;

    // Instantiate a tuple struct
    let pair = Pair(1, 0.1);

    // Destructure a tuple struct
    let Pair(integer, decimal) = pair;

    println!("pair contains {:?} and {:?}", integer, decimal);
}