#stack #vector #array #data-structure #no_std

no-std arrayvec

A vector with fixed capacity, backed by an array (it can be stored on the stack too). Implements fixed capacity ArrayVec and ArrayString.

45 releases

✓ Uses Rust 2018 edition

0.5.1 Oct 9, 2019
0.4.12 Oct 9, 2019
0.4.11 Jul 10, 2019
0.4.10 Dec 22, 2018
0.3.9 Jul 30, 2015

#1 in Data structures

Download history 134958/week @ 2019-12-17 83262/week @ 2019-12-24 102220/week @ 2019-12-31 154312/week @ 2020-01-07 140658/week @ 2020-01-14 143984/week @ 2020-01-21 143198/week @ 2020-01-28 142895/week @ 2020-02-04 128713/week @ 2020-02-11 132027/week @ 2020-02-18 134564/week @ 2020-02-25 131416/week @ 2020-03-03 134092/week @ 2020-03-10 141534/week @ 2020-03-17 141164/week @ 2020-03-24 129728/week @ 2020-03-31

663,335 downloads per month
Used in 3,282 crates (200 directly)




A vector with fixed capacity.

Please read the API documentation here

build_status crates crates2

Recent Changes (arrayvec)

  • 0.5.1
    • Add as_ptr, as_mut_ptr accessors directly on the ArrayVec by @tbu- (matches the same addition to Vec which happened in Rust 1.37).
    • Add method ArrayString::len (now available directly, not just through deref to str).
    • Use raw pointers instead of &mut [u8] for encoding chars into ArrayString (uninit best practice fix).
    • Use raw pointers instead of get_unchecked_mut where the target may be uninitialized a everywhere relevant in the ArrayVec implementation (uninit best practice fix).
    • Changed inline hints on many methods, mainly removing inline hints
    • ArrayVec::dispose is now deprecated (it has no purpose anymore)
  • 0.4.12
    • Use raw pointers instead of get_unchecked_mut where the target may be uninitialized a everywhere relevant in the ArrayVec implementation.
  • 0.5.0
    • Use MaybeUninit (now unconditionally) in the implementation of ArrayVec
    • Use MaybeUninit (now unconditionally) in the implementation of ArrayString
    • The crate feature for serde serialization is now named serde.
    • Updated the Array trait interface, and it is now easier to use for users outside the crate.
    • Add FromStr impl for ArrayString by @despawnerer
    • Add method try_extend_from_slice to ArrayVec, which is always effecient by @Thomasdezeeuw.
    • Add method remaining_capacity by @Thomasdezeeuw
    • Improve performance of the extend method.
    • The index type of zero capacity vectors is now itself zero size, by @clarfon
    • Use drop_in_place for truncate and clear methods. This affects drop order and resume from panic during drop.
    • Use Rust 2018 edition for the implementation
    • Require Rust 1.36 or later, for the unconditional MaybeUninit improvements.
  • 0.4.11
    • In Rust 1.36 or later, use newly stable MaybeUninit. This extends the soundness work introduced in 0.4.9, we are finally able to use this in stable. We use feature detection (build script) to enable this at build time.
  • 0.4.10
    • Use repr(C) in the union version that was introduced in 0.4.9, to allay some soundness concerns.
  • 0.4.9
    • Use union in the implementation on when this is detected to be supported (nightly only for now). This is a better solution for treating uninitialized regions correctly, and we'll use it in stable Rust as soon as we are able. When this is enabled, the ArrayVec has no space overhead in its memory layout, although the size of the vec should not be relied upon. (See #114)
    • ArrayString updated to not use uninitialized memory, it instead zeros its backing array. This will be refined in the next version, since we need to make changes to the user visible API.
    • The use_union feature now does nothing (like its documentation foretold).
  • 0.4.8
    • Implement Clone and Debug for IntoIter by @clarcharr
    • Add more array sizes under crate features. These cover all in the range up to 128 and 129 to 255 respectively (we have a few of those by default):
      • array-size-33-128
      • array-size-129-255
  • 0.4.7
    • Fix future compat warning about raw pointer casts
    • Use drop_in_place when dropping the arrayvec by-value iterator
    • Decrease mininum Rust version (see docs) by @jeehoonkang
  • 0.3.25
    • Fix future compat warning about raw pointer casts
  • 0.4.6
    • Fix compilation on 16-bit targets. This means, the 65536 array size is not included on these targets.
  • 0.3.24
    • Fix compilation on 16-bit targets. This means, the 65536 array size is not included on these targets.
    • Fix license files so that they are both included (was fixed in 0.4 before)
  • 0.4.5
    • Add methods to ArrayString by @DenialAdams:
      • .pop() -> Option<char>
      • .truncate(new_len)
      • .remove(index) -> char
    • Remove dependency on crate odds
    • Document debug assertions in unsafe methods better
  • 0.4.4
    • Add method ArrayVec::truncate() by @niklasf
  • 0.4.3
    • Improve performance for ArrayVec::extend with a lower level implementation (#74)
    • Small cleanup in dependencies (use no std for crates where we don't need more)
  • 0.4.2
    • Add constructor method new to CapacityError.
  • 0.4.1
    • Add Default impl to ArrayString by @tbu-
  • 0.4.0
    • Reformed signatures and error handling by @bluss and @tbu-:
      • ArrayVec's push, insert, remove, swap_remove now match Vec's corresponding signature and panic on capacity errors where applicable.
      • Add fallible methods try_push, insert and checked methods pop_at, swap_pop.
      • Similar changes to ArrayString's push methods.
    • Use a local version of the RangeArgument trait
    • Add array sizes 50, 150, 200 by @daboross
    • Support serde 1.0 by @daboross
    • New method .push_unchecked() by @niklasf
    • ArrayString implements PartialOrd, Ord by @tbu-
    • Require Rust 1.14
    • crate feature use_generic_array was dropped.
  • 0.3.23
    • Implement PartialOrd, Ord as well as PartialOrd<str> for ArrayString.
  • 0.3.22
    • Implement Array for the 65536 size
  • 0.3.21
    • Use encode_utf8 from crate odds
    • Add constructor ArrayString::from_byte_string
  • 0.3.20
    • Simplify and speed up ArrayString’s .push(char)-
  • 0.3.19
    • Add new crate feature use_generic_array which allows using their GenericArray just like a regular fixed size array for the storage of an ArrayVec.
  • 0.3.18
    • Fix bounds check in ArrayVec::insert! It would be buggy if self.len() < index < self.capacity(). Take note of the push out behavior specified in the docs.
  • 0.3.17
    • Added crate feature use_union which forwards to the nodrop crate feature
    • Added methods .is_full() to ArrayVec and ArrayString.
  • 0.3.16
    • Added method .retain() to ArrayVec.
    • Added methods .as_slice(), .as_mut_slice() to ArrayVec and .as_str() to ArrayString.
  • 0.3.15
    • Add feature std, which you can opt out of to use no_std (requires Rust 1.6 to opt out).
    • Implement Clone::clone_from for ArrayVec and ArrayString
  • 0.3.14
    • Add ArrayString::from(&str)
  • 0.3.13
    • Added DerefMut impl for ArrayString.
    • Added method .simplify() to drop the element for CapacityError.
    • Added method .dispose() to ArrayVec
  • 0.3.12
    • Added ArrayString, a fixed capacity analogy of String
  • 0.3.11
    • Added trait impls Default, PartialOrd, Ord, Write for ArrayVec
  • 0.3.10
    • Go back to using external NoDrop, fixing a panic safety bug (issue #3)
  • 0.3.8
    • Inline the non-dropping logic to remove one drop flag in the ArrayVec representation.
  • 0.3.7
    • Added method .into_inner()
    • Added unsafe method .set_len()


Dual-licensed to be compatible with the Rust project.

Licensed under the Apache License, Version 2.0 http://www.apache.org/licenses/LICENSE-2.0 or the MIT license http://opensource.org/licenses/MIT, at your option. This file may not be copied, modified, or distributed except according to those terms.