Code shared from the Rust Playground

playground.rs

#![allow(dead_code)]
#![allow(unused_variables)]
#[macro_use]
extern crate log;

#[derive(Debug)]
enum Person {
    // 一个 `enum` 可能是个 `unit-like`（类单元结构体），
    Engineer,
    Scientist,
    // 或像一个元组结构体，
    Height(i32),
    Weight(i32),
    // 或像一个普通的结构体。
    Info { name: String, height: i32 }
}

enum R {
    RIGHT = 1,
    WRONG,
}

trait MyTrait {
    fn print(&self, message: &str);
    fn print2(&self, message: &str, r: R);
}

struct Data {
    a: String
}

impl MyTrait for Data {
    fn print(&self, message: &str) {
        println!("{}: {}", self.a, message);
    }
    fn print2(&self, message: &str, r: R) {
        println!("{}: {} {}", self.a, message, r as u8);
    }
}

fn main() {
    let person = Person::Info {
        name: "mmzhou".to_string(), 
        height: 180
    };
    match person {
        Person::Info {name, height} => {
            println!("{}'s height is {}", name, height);
        },
        _ => println!("Not found")
    }
    debug!("Person::Engineer = {:?}", Person::Engineer);
    
    let d1 = Data {a: "d1 test".to_string()};
    d1.print("test");
    
    let d2: &MyTrait = &Data {a: "d2 test".to_string()};
    d2.print2("test", R::RIGHT);
    
    let i = 1;
    let j = &i;
    let m = *j;
    println!("Number: {}", m);
    println!("Number: {}", i);
    
    let s = "hello";
    println!("length: {}", s.len());
    println!("length: {}", (&s).len());
    println!("length: {}", (&&&&&&&&&&&&&s).len());
    
    match 1 {
        _ => println!("match _ test {:?}", _),
    }
}