Rust-05 Vec

Vec

Vec is a contiguous growable array type.

pub struct Vec<T, A = Global>
where
  A: Allocator,
  { ... }

Examples

We can declare a mutable/immutable Vec by Vec::new()

let mut mut_vec = Vec::new();
let vec = Vec::new();

We can also declare a vec by vec! macro

let mut mut_vec = vec![1,2,3];
let vec = vec![1,2,3];

Macro vec!

macro_rules! vec {
    () => { ... };
    ($elem:expr; $n:expr) => { ... };
    ($($x:expr),+ $(,)?) => { ... };
}

There are two forms of this macro vec!

• Create a Vec containing a given list of elements:

let v = vec![1, 2, 3];
assert_eq!(v[0], 1);
assert_eq!(v[1], 2);
assert_eq!(v[2], 3);

• Create a Vec from a given element and size:

let v = vec![1; 3];
assert_eq!(v, [1, 1, 1]);