Rust的结构体和枚举比其他语言更强大，配合模式匹配可以优雅地处理复杂数据。 ## 结构体 ```rust #[derive(Debug)] struct User { username: String, email: String, sign_in_count: u64, active: bool, } impl User { fn new(username: String, email: String) -> Self { Self { username, email, sign_in_count: 0, active: true, } } fn summary(&self) -> String { format!("{} ({}) - {} visits", self.username, self.email, self.sign_in_count) } } ``` ## 元组结构体与单元结构体 ```rust struct Color(i32, i32, i32); struct AlwaysEqual; ``` ## 枚举 Rust枚举可以携带数据： ```rust enum Message { Quit, Move { x: i32, y: i32 }, Write(String), ChangeColor(i32, i32, i32), } impl Message { fn process(&self) { match self { Message::Quit => println!("Quit"), Message::Move { x, y } => println!("Move to ({}, {})", x, y), Message::Write(text) => println!("Write: {}", text), Message::ChangeColor(r, g, b) => println!("Color: ({}, {}, {})", r, g, b), } } } ``` ## 模式匹配 ```rust let value = Some(7); match value { Some(1) => println!("one"), Some(2..=5) => println!("two to five"), Some(n) if n > 10 => println!("big: {}", n), Some(_) => println!("other"), None => println!("none"), } if let Some(n) = value { println!("Got: {}", n); } ``` Rust的枚举和模式匹配组合是表达业务逻辑的利器，比传统的继承体系更灵活。