Rust语言之结构体和枚举的用途与高级功能详解

struct Rectangle {
    width: u32,
    height: u32,
}

impl Rectangle {
    fn area(&self) -> u32 { // 通过 impl 块添加结构体方法
        self.width * self.height
    }

    fn can_hold(&self, other: &Rectangle) -> bool {
        self.width > other.width && self.height > other.height
    }
}

fn main() {
    let rect1 = Rectangle { width: 30, height: 50 };
    let rect2 = Rectangle { width: 20, height: 40 };

    println!("矩形 1 的面积：{}", rect1.area());
    println!("矩形 1 是否能容纳矩形 2：{}", rect1.can_hold(&rect2));
}

enum Message {
    Quit,
    Move { x: i32, y: i32 },
    Write(String),
    ChangeColor(u8, u8, u8),
}

impl Message {
    fn call(&self) {
        // 处理不同的 Message 成员
    }
}

fn main() {
    let message = Message::Write(String::from("Hello"));

    match message {
        Message::Quit => println!("退出"),
        Message::Move { x, y } => println!("移动到 ({}, {})", x, y),
        Message::Write(text) => println!("输出：{}", text),
        Message::ChangeColor(r, g, b) => println!("颜色变为 RGB({}, {}, {})", r, g, b),
    }
}

enum Option<T> {
    Some(T),
    None,
}

impl<T> Option<T> {
    fn unwrap(self) -> T {
        match self {
            Option::Some(value) => value,
            Option::None => panic!("不能解包 None 值"),
        }
    }
}

fn main() {
    let some_value: Option<i32> = Option::Some(42);
    let none_value: Option<i32> = Option::None;

    println!("Some 值：{}", some_value.unwrap());
    // println!("None 值：{}", none_value.unwrap()); // 这行代码会引发 panic
}