Crate arraydeque

A circular buffer with fixed capacity. Requires Rust 1.20+

It can be stored directly on the stack if needed.

This queue has O(1) amortized inserts and removals from both ends of the container. It also has O(1) indexing like a vector. The contained elements are not required to be copyable

This crate is inspired by bluss/arrayvec

Feature Flags

The arraydeque crate has the following cargo feature flags:

• std
  • Optional, enabled by default
  • Conversions between ArrayDeque and Vec
  • Use libstd

Usage

First, add the following to your Cargo.toml:

[dependencies]
arraydeque = "0.3"

Next, add this to your crate root:

extern crate arraydeque;

Currently arraydeque by default links to the standard library, but if you would instead like to use arraydeque in a #![no_std] situation or crate you can request this via:

[dependencies]
arraydeque = { version = "0.3", default-features = false }

Capacity

Note that the capacity() is always backend_array.len() - 1.

Behaviors

ArrayDeque provides two different behaviors of pushing element when it's full, Saturating and Wrapping. The behavior is indicated by a marker type parameter of ArrayDeque, which defaults to Saturating.

Saturating

Pushing any element when ArrayDeque is full will directly return an Err(CapacityError) containing the element attempting to push, leaving the ArrayDeque unchanged.

use arraydeque::{ArrayDeque, Saturating, CapacityError};

let mut tester: ArrayDeque<[_; 3], Saturating> = ArrayDeque::new();

assert_eq!(tester.push_back(1), Ok(()));
assert_eq!(tester.push_back(2), Ok(()));
assert_eq!(tester.push_back(3), Err(CapacityError { element: 3 }));

Wrapping

Pushing any element when ArrayDeque is full will pop an element at the other side to spare room.

use arraydeque::{ArrayDeque, Wrapping};

let mut tester: ArrayDeque<[_; 3], Wrapping> = ArrayDeque::new();

assert_eq!(tester.push_back(1), None);
assert_eq!(tester.push_back(2), None);
assert_eq!(tester.push_back(3), Some(1));

Reexports

pub use behavior::Saturating;

pub use behavior::Wrapping;

Modules

behavior

Behavior semantics for ArrayDeque.

Structs

ArrayDeque	A fixed capacity ring buffer.
CapacityError	Error value indicating insufficient capacity
Drain	Draining ArrayDeque iterator
IntoIter	By-value ArrayDeque iterator
Iter	ArrayDeque iterator
IterMut	ArrayDeque mutable iterator

Traits

Array	Trait for fixed size arrays.
RangeArgument	IndexRange is implemented by Rust's built-in range types, produced by range syntax like .., a.., ..b or c..d.