Rust std::vec::Vec API

Constructs a new, empty Vec. The vector will not allocate until elements are pushed onto it.

let v: Vec<i32> = Vec::new();
assert!(v.is_empty());

Constructs a new, empty Vec with at least the specified capacity.

let mut v: Vec<i32> = Vec::with_capacity(10);
for i in 0..10 {
    v.push(i);
}
// No reallocations happened during the loop

Appends an element to the back of a collection.

let mut v = vec![1, 2];
v.push(3);
assert_eq!(v, [1, 2, 3]);

Removes the last element from a vector and returns it, or None if it is empty.

let mut v = vec![1, 2, 3];
assert_eq!(v.pop(), Some(3));
assert_eq!(v, [1, 2]);

Returns the number of elements in the vector, also referred to as its 'length'.

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

Returns a reference to an element or subslice depending on the type of index, returning None if out of bounds.

let v = vec![10, 20, 30];
assert_eq!(v.get(1), Some(&20));
assert_eq!(v.get(5), None);

Returns an iterator that yields references to the elements of the vector in order.

let v = vec![1, 2, 3];
let sum: i32 = v.iter().sum();
assert_eq!(sum, 6);

Extends a collection with the contents of an iterator.

let mut v = vec![1, 2];
v.extend([3, 4, 5]);
assert_eq!(v, [1, 2, 3, 4, 5]);