gw-rust-programming-tutorial 0.1.0

//生命一个trait,默认实现
pub trait Summary {
    fn summarize(&self) -> String{
        String::from("(Read more...)")
    }
}

//为类型实现 trait
pub struct NewsArticle {
    pub headline: String,
    pub location: String,
    pub author: String,
    pub content: String,
}

//为NewsArticle实现trait Summary
impl Summary for NewsArticle {
    fn summarize(&self) -> String {
        format!("{}, by {} ({})", self.headline, self.author, self.location)
    }
}

pub struct Tweet {
    pub username: String,
    pub content: String,
    pub reply: bool,
    pub retweet: bool,
}

//Tweet Summary
impl Summary for Tweet {
    fn summarize(&self) -> String {
        format!("{}: {}", self.username, self.content)
    }
}
pub fn test_trait_fn()
{
    let tweet = Tweet {
        username: String::from("horse_ebooks"),
        content: String::from("of course, as you probably already know, people"),
        reply: false,
        retweet: false,
    };
    
    //类型Tweet实现了trait Summary，可以直接调用summarize
    println!("1 new tweet: {}", tweet.summarize());
}

use std::fmt::Display;

struct Pair<T> {
    x: T,
    y: T,
}

impl<T> Pair<T> {
    fn new(x: T, y: T) -> Self {
        Self {
            x,
            y,
        }
    }
}

impl<T: Display + PartialOrd> Pair<T> {
    fn cmp_display(&self) {
        if self.x >= self.y {
            println!("The largest member is x = {}", self.x);
        } else {
            println!("The largest member is y = {}", self.y);
        }
    }
}

// impl<T: Display> ToString for T {
//     // --snip--
//     println!("ssssssssssss");
//     String::from("asdasdasd")
// }