Generics

There is a new edition of the book and this is an old link.

Generics are abstract stand-ins for concrete types or other properties.

struct Point<T, U> {
    x: T,
    y: U,
}

fn main() {
    let both_integer = Point { x: 5, y: 10 };
    let both_float = Point { x: 1.0, y: 4.0 };
    let integer_and_float = Point { x: 5, y: 4.0 };
}Run

Here are the relevant sections in the new and old books:

in the current edition: Ch 10.00 — Generic Types, Traits, and Lifetimes
In the first edition: Ch 3.18 — Generics