staticvec

staticvec copied to clipboard

Implements a fixed-capacity stack-allocated Vec alternative backed by an array, using const generics.

Note: the word "static" here is meant by the traditional definition of "unchanging" or "not dynamic".

This crate does not use literal static variables for anything (but does provide multiple ways to instantiate a StaticVec as a static or const variable if desired).

Fully #![no_std] compatible (with almost no loss of functionality) by setting default-features = false for the staticvec dependency in your Cargo.toml.

Optional support for serialization and deserialization of the StaticVec struct via serde is available by activating the serde crate feature.

StaticVec also implements both Deref and DerefMut to [T], meaning that all existing slice methods are accessible through instances of it and that references to it can be used in contexts where [T] is expected.

As of version 0.8.0, this crate additionally provides a fixed-capacity StaticString struct, which is built around an instance of StaticVec<u8, N>.

As of version 0.8.5, a fixed-capacity StaticHeap struct based on the standard library BinaryHeap and built around an instance of StaticVec<T, N> has been added as well.

Contributions/suggestions/etc. very welcome!

Minimum supported Rust version: this is a nightly-only crate at the moment due to the use of various feature gates that provide functionality beyond the scope of stabilized minimal subsets such as min_const_generics and min_const_fn.

A basic usage example:

use staticvec::{staticvec, StaticVec};

fn main() {
  let mut v = StaticVec::<usize, 64>::new();
  for i in 0..v.capacity() {
    v.push(i);
  }
  for i in &v {
    println!("{}", i);
  }
  v.clear();
  v.insert(0, 47);
  v.insert(1, 48);
  v.insert(2, 49);
  v.insert(v.len() - 1, 50);
  v.insert(v.len() - 2, 51);
  v.insert(v.len() - 3, 52);
  for i in &v {
    println!("{}", i);
  }
  for i in &v.reversed().drain(2..4) {
    println!("{}", i);
  }
  while v.is_not_empty() {
    println!("{}", v.remove(0));
  }
  for f in staticvec![12.0, 14.0, 15.0, 16.0].iter().skip(2) {
    println!("{}", f);
  }
  for i in staticvec![
    staticvec![14, 12, 10].sorted(),
    staticvec![20, 18, 16].reversed(),
    staticvec![26, 24, 22].sorted(),
    staticvec![32, 30, 28].reversed(),
  ]
  .iter()
  .flatten()
  .collect::<StaticVec<usize, 12>>()
  .iter() {
    println!("{}", i);
  }
  // The type parameter is inferred as `StaticVec<usize, 16>`.
  let filled = StaticVec::<_, 6>::filled_with_by_index(|i| {
    staticvec![
      i + 1,
      i + 2,
      i + 3,
      i + 4,
    ]
    .concat(&staticvec![6, 6, 7, 7])
    .intersperse((i + 4) * 4)
  });
  println!("{:?}", filled);
}

License:

Licensed under either the MIT license or version 2.0 of the Apache License. Your choice as to which! Any source code contributions will be dual-licensed in the same fashion.