Traits and Generics

Generics

One Function, Many Types

A generic function works for any type that satisfies its trait bounds. Here it finds the largest item in a slice.

Program

Play the program to find the largest number with a generic helper.

generics.rs 
fn largest<T: PartialOrd + Copy>(items: &[T]) -> T {
    let mut top = items[0];
    for &item in items {
        if item > top {
            top = item;
        }
    }
    top
}

fn main() {
    let nums = [3, 7, 2, 9, 4];
    let biggest = largest(&nums);
    println!("{biggest}");
}
generic `largest<T>` works for any type `T`.
trait bound `T: PartialOrd + Copy` requires comparison and copy.
slice `&[T]` borrows a sequence of items.