最近話題になるRust言語とRust言語機能（OOP, 循環数型プログラミング、メモリー管理）について簡単な説明です。

1. Rustとは
パヴェウ・ルシン
株式会社ブリリアントサービス
2015.04.07

2.  自己紹介
 会社の紹介
 なぜRustか?
 Rustの基本
アジェンダ

3.  Paweł Rusin (パヴェウ・ルシン)
 pawel.rusin@brilliantservice.co.jp
Facebook: Paweł Rusin (iofar@o2.pl)
Twitter: RusinPaw
 会社：
株式会社ブリリアントサービス
 業務：
開発部のエンジニア（主にiOSアプリケーショ
ン開発）
自己紹介

4.  株式会社ブリリアントサービス
 本社：大阪
 支社：東京（品川）、シリコンバレー
 アプリケーション開発、O2Oサービス開発、スマートデ
バイス開発
会社の紹介

5.  ジェスチャーで操作できる電脳メガネ
 ジェスチャー認識システム
 拡張現実で独特な体験を提供
 FreeBSDベース
 開発言語はCとObjective-C...
miramaについて

6. Objective-C
Swift

7. C Objective-C
システム
パーフォーマンス
OO
P
豊かなstandard library
?
モダーン
安定（メモリー管理）
書きやすい
他の希望特徴

8. Rustとは
●
2009年からMozilla Researchで開発しているプログラ
ミング言語
●
マルチパラタイム（純関数型、オブジェクト指向な
ど）
●
クライアントーサーバーアピリケーションに向け
●
特徴：メモリー・セーフ、並列性
●
開発中：現在点1.0.0 beta（2015年5月ver1.0リリス予
定）

10. 参照
●
Rust book: https://doc.rust-lang.org/book/ (nightly bu
ild)
●
Rust documentation: http://doc.rust-lang.org/
●
IRC irc.mozilla.org #rust

11. $ curl -sf -L https://static.rust-lang.org/rustup.sh | sudo sh
$ curl -f -L https://static.rust-lang.org/rustup.sh -O
$ sudo sh rustup.sh
インストール仕
方
バイナリかソースからインストール可能：
http://www.rust-lang.org/install.html
$ git clone https://github.com/yohanesu/tokyorust-part1

12. fn main() {
println!("Hello World!");
}
example1.rs
マクロ
$ rustc example1.rc
$ ./example1

13. fn main() {
let n = 5;
if n < 0 {
println!("{} is negative", n);
} else if n > 0 {
println!("{} is positive", n);
} else {
println!("{} is zero", n);
}
}
example2.rs
Non-mutable!

14. struct Rectangle{
x : i32,
y : i32
}
impl Rectangle{
fn area(&self) -> i32{
self.x*self.y
}
}
fn main() {
let rect = Rectangle{x:2,y:3};
println!("Rectangle area is {}",rect.area());
}
example3.rs (OO
P) struct定義でIV
struct実装でメソッド

15. example4.rs （純関数
型）
不安定機能#![feature(core)]
#![feature(collections)]
use std::iter::AdditiveIterator;
fn main() {
let kanji_array : [String;3] = [
String::from_str("Rust is fun."),
String::from_str("You can use High Order Functions."),
String::from_str("I want to learn more.")];
let char_count = kanji_array.iter().map(|s : &String|s.len()).sum();
println!("Character count: {}", char_count);
}

16. example4.rs （純関数型）
Rust is fun!
You can use High Order Functions!
I want to learn more!
12
33
21
61
sum()
String.len()
String.len()
String.len()
map()

17. メモリー管理
●
バッグの原因：
– freeしない（メモリーリーク）
– freeされたメモリーを使用
– 二回目free
– Null pointer dereference
●
対策
– Smart pointers
– Garbage collector
– ARC (Automatic reference counting)

18. borrow.rs （メモリー管理）
fn main() {
let x = 4;
let y = &x;
println!("Address of x is {:p} address of y is
{:p}",&x,y);
}
Address of x is 0x7fff5fa1795c address of y is 0x7fff5fa1795c

19. –メモリー管理 immutable borr
ow
x x x
y
z

20. example5.rs （メモリー管
理）
fn main() {
let x = 4;
let y = &x;
println!("Address of x is {:p} address of y is
{:p}",&x,y);
*y = 1;
}
borrow.rs:6:4: 6:10 error: cannot assign to immutable borrowed content
`*y`
borrow.rs:6 *y = 1;
^~~~~~
error: aborting due to previous error

21. example5.rs （メモリー管
理）
fn main() {
let mut x = 4;
let y = &x;
println!("Address of x is {:p} address of y is
{:p}",&x,y);
*y = 1;
}
borrow.rs:6:4: 6:10 error: cannot assign to immutable borrowed content
`*y`
borrow.rs:6 *y = 1;
^~~~~~
error: aborting due to previous error

22. example5.rs （メモリー管
理）
fn main() {
let mut x = 4;
let y = &mut x;
println!("Address of x is {:p} address of y is
{:p}",&x,y);
*y = 1;
}
borrow.rs:5:58: 5:59 error: cannot borrow `x` as immutable because it is
also borrowed as mutable
borrow.rs:5 println!("Address of x is {:p} address of y is {:p}",&x,y);
^
note: in expansion of format_args!
<std macros>:2:25: 2:58 note: expansion site
<std macros>:1:1: 2:62 note: in expansion of print!
<std macros>:3:1: 3:54 note: expansion site
<std macros>:1:1: 3:58 note: in expansion of println!
borrow.rs:5:4: 5:63 note: expansion site
borrow.rs:4:17: 4:18 note: previous borrow of `x` occurs here; the mutable
borrow prevents subsequent moves, borrows, or modification of `x` until
the borrow ends
borrow.rs:4 let y = &mut x;
^
borrow.rs:7:2: 7:2 note: previous borrow ends here
borrow.rs:1 fn main() {
...
borrow.rs:7 }
^
error: aborting due to previous error

23. example5.rs （メモリー管
理）
fn main() {
let mut x = 4;
let y = &mut x;
println!("Address of x is {:p} address of y is
{:p}",&x,y);
*y = 1;
}
borrow.rs:5:58: 5:59 error: cannot borrow `x` as immutable because it is
also borrowed as mutable
borrow.rs:5 println!("Address of x is {:p} address of y is {:p}",&x,y);
^
note: in expansion of format_args!
<std macros>:2:25: 2:58 note: expansion site
<std macros>:1:1: 2:62 note: in expansion of print!
<std macros>:3:1: 3:54 note: expansion site
<std macros>:1:1: 3:58 note: in expansion of println!
borrow.rs:5:4: 5:63 note: expansion site
borrow.rs:4:17: 4:18 note: previous borrow of `x` occurs here; the mutable
borrow prevents subsequent moves, borrows, or modification of `x` until
the borrow ends
borrow.rs:4 let y = &mut x;
^
borrow.rs:7:2: 7:2 note: previous borrow ends here
borrow.rs:1 fn main() {
...
borrow.rs:7 }
^
error: aborting due to previous error

24. example5.rs （メモリー管
理）
fn main() {
let mut x = 4;
let y = &mut x;
//println!("Address of x is {:p} address of y is {:p}",&x,y);
*y = 1;
}
成功!

25. example5.rs （メモリー管
理）
fn main() {
let mut x = 4;
if true {
let y = &mut x;
println!("Address of y is {:p}",y);
*y = 1;
}
println!("Address of x is {:p}",&x);
}
Address of y is 0x7fff51b4795c
Address of x is 0x7fff51b4795c
yのlifetime = 借りる範囲

26. –メモリー管理 mutable borrow
mut x x mut x
mut y

27. example5.rs （メモリー管
理）
fn main() {
let x = Box::new(4);
let y = x;
println!("Value of y is {}",y);
}
Value of y is 4

28. example5.rs （メモリー管
理）
fn main() {
let x = Box::new(4);
let y = x;
println!("Value of y is {}",y);
println!("Value of x is {}",x);
}
borrow.rs:6:32: 6:33 error: use of moved value: `x`
borrow.rs:6 println!("Value of x is {}",x);
^
note: in expansion of format_args!
<std macros>:2:25: 2:58 note: expansion site
<std macros>:1:1: 2:62 note: in expansion of print!
<std macros>:3:1: 3:54 note: expansion site
<std macros>:1:1: 3:58 note: in expansion of println!
borrow.rs:6:4: 6:35 note: expansion site
borrow.rs:4:8: 4:9 note: `x` moved here because it has type
`Box<i32>`, which is moved by default
borrow.rs:4 let y = x;
^
borrow.rs:4:9: 4:9 help: use `ref` to override
error: aborting due to previous error

29. example5.rs （メモリー管
理）fn main() {
let x = Box::new(4);
println!("Value of x is {}",x);
if true {
let y = x;
println!("Value of y is {}",y);
}
println!("Value of x is {}",x);
}
borrow.rs:11:35: 11:36 error: use of moved value: `x`
borrow.rs:11 println!("Value of x is {}",x);
^
note: in expansion of format_args!
<std macros>:2:25: 2:58 note: expansion site
<std macros>:1:1: 2:62 note: in expansion of print!
<std macros>:3:1: 3:54 note: expansion site
<std macros>:1:1: 3:58 note: in expansion of println!
borrow.rs:11:7: 11:38 note: expansion site
borrow.rs:8:11: 8:12 note: `x` moved here because it has type `Box<i32>`,
which is moved by default
borrow.rs:8 let y = x;
^
borrow.rs:8:12: 8:12 help: use `ref` to override
error: aborting due to previous error
yのlifetime

30. example5.rs （メモリー管
理）fn main() {
let x = Box::new(4);
println!("Value of x is {}",x);
if true {
let y = x;
println!("Value of y is {}",y);
x = y;
}
println!("Value of x is {}",x);
}
borrow.rs:11:35: 11:36 error: use of moved value: `x`
borrow.rs:11 println!("Value of x is {}",x);
^
note: in expansion of format_args!
<std macros>:2:25: 2:58 note: expansion site
<std macros>:1:1: 2:62 note: in expansion of print!
<std macros>:3:1: 3:54 note: expansion site
<std macros>:1:1: 3:58 note: in expansion of println!
borrow.rs:11:7: 11:38 note: expansion site
borrow.rs:8:11: 8:12 note: `x` moved here because it has type `Box<i32>`,
which is moved by default
borrow.rs:8 let y = x;
^
borrow.rs:8:12: 8:12 help: use `ref` to override
error: aborting due to previous error

31. example5.rs （メモリー管
理）fn main() {
let mut x = Box::new(4);
println!("Value of x is {}",x);
if true {
let y = x;
println!("Value of y is {}",y);
x = y;
}
println!("Value of x is {}",x);
}
Value of x is 4
Value of y is 4
Value of x is 4

32. メモリー管理 - move
x x
y

33. 以上 。。。？