examples/rust-by-example-structures/src/main.rs
// An attribute to hide warnings for unused code.
#![allow(dead_code)]
#[derive(Debug)]
struct Person {
name: String,
age: u8,
}
// A unit struct
struct Unit;
// A tuple struct
struct Pair(i32, f32);
// A struct with two fields
#[derive(Debug)]
struct Point {
x: f32,
y: f32,
}
// Structs can be reused as fields of another struct
#[derive(Debug)]
struct Rectangle {
// A rectangle can be specified by where the top left and bottom right
// corners are in space.
top_left: Point,
bottom_right: Point,
}
fn main() {
// Create struct with field init shorthand
let name = String::from("Peter");
let age = 27;
// let peter = Person {
// name: name,
// age: age,
// };
let peter = Person { name, age };
let f_name = String::from("Jane");
let jane = Person {
name: f_name,
age: 25
};
// Print debug struct
println!("{:?}", peter);
println!("{:?}", jane);
// Instantiate a `Point`
let point = Point { x: 5.2, y: 0.4 };
let another_point: Point = Point { x: 10.3, y: 0.2 };
// Access the fields of the point
println!("point coordinates: ({}, {})", point.x, point.y);
// Make a new point by using struct update syntax to use the fields of our
// other one
let bottom_right = Point { x: 10.3, ..another_point };
// `bottom_right.y` will be the same as `another_point.y` because we used that field
// from `another_point`
println!("second point: ({}, {})", bottom_right.x, bottom_right.y);
// Destructure the point using a `let` binding
let Point { x: left_edge, y: top_edge } = point;
let rectangle = Rectangle {
// struct instantiation is an expression too
top_left: Point { x: left_edge, y: top_edge },
bottom_right: bottom_right,
};
println!("{:?}", rectangle);
// Instantiate a unit struct
let _unit = Unit;
// Instantiate a tuple struct
let pair = Pair(1, 0.1);
// Access the fields of a tuple struct
println!("pair contains {:?} and {:?}", pair.0, pair.1);
// Destructure a tuple struct
let Pair(integer, decimal) = pair;
println!("pair contains {:?} and {:?}", integer, decimal);
}