Module allocator_api2::vec

Expand description

A contiguous growable array type with heap-allocated contents, written Vec<T>.

Vectors have O(1) indexing, amortized O(1) push (to the end) and O(1) pop (from the end).

Vectors ensure they never allocate more than isize::MAX bytes.

Examples

You can explicitly create a Vec with Vec::new:

let v: Vec<i32> = Vec::new();

…or by using the [vec!] macro:

let v: Vec<i32> = vec![];

let v = vec![1, 2, 3, 4, 5];

let v = vec![0; 10]; // ten zeroes

You can push values onto the end of a vector (which will grow the vector as needed):

let mut v = vec![1, 2];

v.push(3);

Popping values works in much the same way:

let mut v = vec![1, 2];

let two = v.pop();

Vectors also support indexing (through the Index and IndexMut traits):

let mut v = vec![1, 2, 3];
let three = v[2];
v[1] = v[1] + 5;