Module show_notes::e025

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Traits Deep Dive, Part 3

  • Date: July 4, 2018
  • Subject: Closure traits, impl trait, dyn trait, and object safety!
  • Script
  • Audio

§Show Notes

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You can see all of the pieces of the final example described in the show here (and the module has the required definitions for Point).

let points = vec![
    Point { x: 1.0, y: 2.0 },
    Point { x: 12.0, y: 4.3 },
    Point { x: -5.4, y: 18.7 },

let origin = Point::default();

// This is the version we start with. It works fine, but it's not elegant.
let distances_inline: Vec<f32> = points
    .map(|point| {
        let change = point - &origin;
        (change.x.powi(2) + change.y.powi(2)).sqrt()

// This version is *much* cleaner!
let distances_impl: Vec<f32> = points.iter().map(distance_from_impl(&origin)).collect();


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