Module vec

A growable array type with values persisted to storage and lazily loaded.

Values in the Vector are kept in an in-memory cache and are only persisted on Drop.

Vectors ensure they never allocate more than u32::MAX bytes. u32 is used rather than usize as in Vec to ensure consistent behavior on different targets.

Examples

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

use near_sdk::store::Vector;

let v: Vector<i32> = Vector::new(b"a");

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

use near_sdk::store::Vector;

let mut v: Vector<i32> = Vector::new(b"a");

v.push(3);

Popping values works in much the same way:

use near_sdk::store::Vector;

let mut v: Vector<i32> = Vector::new(b"a");
v.extend([1, 2]);

let two = v.pop();

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

use near_sdk::store::Vector;

let mut v: Vector<i32> = Vector::new(b"a");
v.extend([1, 2, 3]);

let three = v[2];
v[1] = v[1] + 5;

Structs

Drain

A draining iterator for Vector<T>.

Iter

An iterator over references to each element in the stored vector.

IterMut

An iterator over exclusive references to each element of a stored vector.

Vector

An iterable implementation of vector that stores its content on the trie. This implementation will load and store values in the underlying storage lazily.