generics.rs

pub trait Summary {
    fn sumarize(&self) -> String {
        format!("(Read more from {}...)", self.sumarize_author())
    }
    fn sumarize_author(&self) -> String;
}

pub trait User {
    fn printUser(&self) -> ();
}

pub struct NewsArticle {
    pub headline: String,
    pub location: String,
    pub author: String,
    pub content: String,
}

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



impl Summary for NewsArticle {
    fn sumarize(&self) -> String {
        format!("{}, by {} ({})", self.headline, self.sumarize_author(), self.location)
    }
    
    fn sumarize_author(&self) -> String {
        format!("{}", self.author)
    }
}

impl Summary for Tweet {
    fn sumarize(&self) -> String {
        format!("{}: {}", self.sumarize_author(), self.content)
    }

    fn sumarize_author(&self) -> String {
        format!("@{}", self.username)
    }
}

impl User for Tweet {
    fn printUser(&self) {
        println!("{}",self.username)
    }
}

impl User for NewsArticle {
    fn printUser(&self) {
        println!("{}", self.author)
    }
}

pub fn notifyUser<T, U> (item: &T, item2: &U)
where T: Summary + User,
      U: Summary + User {
        item.printUser();
        println!("Summary: {}", item.sumarize());
        item2.printUser();
        println!("Summary: {}", item.sumarize());
      }

fn main() {
    let tweet = Tweet {
        username: String::from("my_ebooks"),
        content: String::from("I'm learning Rust"),
        reply: false, 
        retweet: false,
    };
    let article = NewsArticle {
        headline: String::from("Penguins win the Stanley Cup Championship!"),
        location: String::from("Pittsburgh, PA, USA"),
        author: String::from("Iceburgh"),
        content: String::from(
            "The Pittsburgh Penguins once again are the best \
             hockey team in the NHL.",
        ),
    };

    println!("1 New Tweet {}", tweet.sumarize());
    println!("New article avaible {}", article.sumarize());
    notify(&tweet);

    notifyUser(&tweet, &article);
}