Destructuring in Rust

Patterns pull structs, tuples and nested values apart in one binding.

struct Point {
    x: i32,
    y: i32,
}

struct Line {
    from: Point,
    to: Point,
}

fn main() {
    let a = Point { x: 0, y: 0 };
    let b = Point { x: 3, y: 4 };
    let Line { from: Point { x, y }, to } = Line { from: a, to: b };
    println!("from {x},{y} to {},{}", to.x, to.y);

    let (first, .., last) = (1, 2, 3, 4);
    println!("{first} {last}");
}

How it works

1. Field shorthand binds a field to a variable of the same name.
2. Nested patterns reach into a struct inside a struct.
3. .. ignores the parts you did not name.

Keywords and builtins used here

• Line
• Point
• a
• b
• fn
• i32
• let
• main
• struct

The run, in numbers

Lines

19

Characters to type

327

Tokens

125

Three-star pace

85 tpm

At the three-star pace of 85 tokens a minute, this run takes about 88 seconds.

Type this snippet

Step 4 of 4 in Compound values, step 10 of 39 in Language basics.

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Destructuring in other languages

• JavaScript