Try It Yourself - SyntaxStudy Editor

HTML / CSS / JS

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

// Trait bounds with + syntax
fn print_both<T: Debug + Display>(value: T) {
    println!("Display: {value}");
    println!("Debug:   {value:?}");
}

// where clause — cleaner for multiple generics
fn compare_and_print<T, U>(a: T, b: U)
where
    T: Display + PartialOrd,
    U: Debug,
{
    println!("a={a}  b={b:?}");
}

// impl Trait in parameter position — anonymous generic
fn summarise(item: impl Display) -> String {
    format!("[{}]", item)
}

// impl Trait in return position — hides the concrete type
fn make_adder(x: i32) -> impl Fn(i32) -> i32 {
    move |y| x + y
}

// A generic struct with a trait bound
#[derive(Debug)]
struct Wrapper<T: Display> {
    value: T,
}

impl<T: Display> Wrapper<T> {
    fn show(&self) {
        println!("wrapped: {}", self.value);
    }
}

fn main() {
    print_both(42);
    print_both("hello");

compare_and_print(3.14f64, vec![1, 2, 3]);

println!("{}", summarise(100));
    println!("{}", summarise("world"));

let add5 = make_adder(5);
    println!("5 + 10 = {}", add5(10));

let w = Wrapper { value: "rust" };
    w.show();
}