Lib.rs

A Vec-like datastructure which only contains unique entries. It is no_std and makes no use of unsafe code.

lib.rs:

This crate offers a [Vec]-like datastructure which only contains unique entries. It is no_std by default but necessarily requires an allocator. To access elements inside the vector, we implement the Deref trait such that it can be used like a regular [Vec]. We provide distinct types for [PartialEq] and [Eq] traits in order to support a wider variety of use-cases. To modify entries or create new instances, we implement methods which are listed below.

// Create a new empty UniqueVec
use uniquevec::UniqueVec;
let mut uvec = UniqueVec::new();

// Fill it with contents
uvec.push("cellular");
uvec.push("_");
uvec.push("raza");

// The next entry is already contained so it will not be added again.
// We can also check the returned value
let r = uvec.push("cellular");
assert_eq!(r, Some("cellular"));

// Otherwise we can use it similarly to a Vec
assert_eq!(uvec[0], "cellular");
assert_eq!(uvec[1], "_");
assert_eq!(uvec[2], "raza");
assert_eq!(uvec.len(), 3);

for (n, entry) in uvec.into_iter().enumerate() {
    println!("{n}th entry: {entry}");
}

Create and Modify

Implemented Traits

[PartialEq] Warning

Since the [UniqueVec] struct only requires the [PartialEq] trait, some unexpected behaviour might occurr when using it with types such as [f32] or [f64] which do not implement [Eq].

let mut unique_vec = UniqueVec::new();

// Insert two times NAN values
unique_vec.push(1f64);
unique_vec.push(f64::NAN);
unique_vec.push(f64::NAN);
assert_eq!(unique_vec[0], 1f64);
assert!(unique_vec[1].is_nan());
assert!(unique_vec[2].is_nan());
assert_eq!(unique_vec.len(), 3);

For this particular reason, we provide the [UniqueVecEq] struct which can only be used when the entry type implements the [Eq] trait.

// This will compile
let mut unique_vec: UniqueVecEq<_> = UniqueVec::new().into();
unique_vec.push(1usize);

// This will not compile
let mut unique_vec: UniqueVecEq<_> = UniqueVec::new().into();
unique_vec.push(1f64);

Features

• The serde feature offers serialization support.