Vectors
https://doc.rust-lang.org/book/vectors.html
書き換え可能な参照と、書き換え不可能な参照がある。
fn main() { let mut v = vec![1, 2, 3, 4, 5]; for i in &v { // *i = *i + 1; // 不可能 println!("A reference to {}", i); } for i in &mut v { *i = *i + 1; println!("A mutable reference to {}", i); } for i in v { println!("Take ownership of the vector and its element {}", i); } }