Rust 構造体

構造体はフィールドと呼ばれる要素の集まり
構造体はフィールド名と型を持つフィールドを複数持つ
struct Member {
id: String,
name: String,
age: i32,
}

let m = struct Member {
	id: String::from("A0101"),
	name: String::from("Pochi"),
	age: 12,
}

struct Member {
	id: String,
	name: String,
	age: i32,
}

fn main(){
	let m = Member {
		id: String::from("A0101"),
		name: String::from("Pochi"),
		age: 12
	};

	println!("id={:?}", m.id);
	println!("name={:?}", m.name);
	println!("age={:?}", m.age);
}

struct Member {
	id: String,
	name: String,
	age: i32,
}

fn main(){
	let mut m = Member {
		id: String::from("A0101"),
		name: String::from("Pochi"),
		age: 12
	};

	m.name = String::from("Pochi");
	m.age = 14;

	println!("id={:?}", m.id);
	println!("name={:?}", m.name);
	println!("age={:?}", m.age);
}

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

struct Circle {
	center: Point,
	radius: i32,
}

fn main(){
	let c = Circle {
		center: Point{x:10, y:20},
		radius: 25,
	};

	println!("(x,y)=({}, {})", c.center.x, c.center.y);
	println!("半径={}", c.radius);
}

### ジェネリック構造体
任意の型の値を扱えるようにする仕組みをジェネリックという

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

fn main(){
	let p1 = Point { x: 20, y: 10};
	let p2 = Point { x: 5, y: 6.0};

	println!("p1.X={}, p1.y={}",p1.x, p1.y);
	println!("p2.X={}, p2.y={}",p2.x, p2.y);
}

struct Position<T, U, V>{
	x: T,
	y: U,
	z: V,
}

fn main(){
	let pos = Position { x: 5.0, y: 10, z:20.5};

	println!("X={}, y={}, z={}", pos.x, pos.y, pos.z);
}

### 共用体
メンバーが同じメモリ領域を使用するデータ構造

union MyData {
	va: u16,
	vb: u32,
}

fn main(){
	let v = MyData {vb: 0};

	unsafe {
		println!("v.va={}", v.va);
		println!("v.vb={}", v.vb);
	}
}