Empty collections - guaranteed to have nothing!

You may be familiar with the concept of nonempty-collections. The empty-collections crate provides the sister-concept; collections which contain nothing, and never will.

Why, you ask? That is a good question.

use empty_collections::*;

let v: EVec<usize> = EVec::new();
assert!(v.is_empty());

See the documentation for EVec, EMap, and ESet for more examples of their extensive APIs.

The iterators in this crate are the fastest in the entire Rust ecosystem, able to traverse their entire stream in constant time. Simply amazing.

use empty_collections::*;

let v: EVec<i32> = EVec::new();
assert_eq!(0, v.into_iter().sum());

• serde: Guarantee that collections you send/receive over the wire are empty.