Rust Traits

trait Summary {
    fn summarize(&self) -> String;
}

struct Article {
    title: String,
    author: String,
    content: String,
}

impl Summary for Article {
    fn summarize(&self) -> String {
        format!("{} — by {}", self.title, self.author)
    }
}

fn notify(item: &impl Summary) {
    println!("Breaking: {}", item.summarize());
}

// Equivalent with trait bound syntax
fn notify<T: Summary>(item: &T) {
    println!("Breaking: {}", item.summarize());
}

use std::fmt::{Display, Debug};

fn compare<T: Display + Debug>(a: &T, b: &T) {
    println!("{a:?} vs {b:?}");
}

trait Greet {
    fn greet(&self) -> String {
        "Hello!".to_string()  // default — can be overridden
    }
}

struct User { name: String }

impl Greet for User {
    fn greet(&self) -> String {
        format!("Namaste, {}!", self.name)
    }
}

#[derive(Debug, Clone, PartialEq)]
struct Point {
    x: f64,
    y: f64,
}