Trait Bounds

Constrain generic types with trait bounds.

Difficulty

Intermediate

Code

use std::fmt::Display;

fn print_pair<T: Display, U: Display>(first: T, second: U) {
    println!("{}, {}", first, second);
}

fn sum<T>(items: &[T]) -> T
where
    T: std::ops::Add<Output = T> + Copy + Default,
{
    let mut total = T::default();
    for &item in items {
        total = total + item;
    }
    total
}

fn main() {
    print_pair(42, "hello");
    println!("sum: {}", sum(&[1, 2, 3, 4, 5]));
}

Explanation

This example demonstrates how to use trait bounds in Rust. Read the code carefully to understand the flow. Pay attention to where values are created, borrowed, moved, or consumed.

Key Concepts

• Rust's strong type system catches errors at compile time
• Ownership and borrowing rules ensure memory safety
• Pattern matching makes code expressive and exhaustive

Related Topics

Browse more examples in the generics category to build a complete understanding of this topic.