General purpose global allocator(s) with static storage.
Provides allocator based data structures for extremely resource constrained
environments where the only memory guaranteed is your program's image in memory
as provided by the loader. This includes a Slab-allocator and a FixedVec.
Possible use cases are OS-less development, embedded, bootloaders (even stage0/1 maybe, totally untested). The primary goals are minimalism, simplicity, and correctness.
This library aims to provide functionality similar to the standard alloc
crate. It is obviously far from complete, and contributions with bug fixes or
more allocators are welcome. As a general principle those should provide
mechanisms, not policy, have a usable direct api that does not require them to
override any singleton such as the single global allocator.
Feature requests and 'help' issues will be closed, drafts will be decided on the spot. Whatever submitted should have simplicity and composability in mind, ideas that can not be put into a draft form are likely too complex or not focussed enough. PRs should be extremely reluctant with introducing new dependencies and should contain no non-optional dependency.
As a global allocator for alloc:
```rust use static_alloc::Slab;
static A: Slab<[u8; 1 << 16]> = Slab::uninit();
fn main() {
// Vec occupying 1 << 7 bytes
let v = vec![0xdeadbeef_u32; 32];
// Can also allocate values directly.
// Even without `alloc::boxed::Box`.
let buffer: &'static mut [u32; 32] = A.leak([0; 32])
.unwrap();
buffer.copy_from_slice(&v);
} ```
As local memory pools for fixed capacity FixedVec:
```rust use static_alloc::{FixedVec, Uninit}; use core::mem::MaybeUninit;
let mut pool = MaybeUninit::<[u8; 1024]>::uninit(); let memory = Uninit::from(&mut pool); let mut vector = FixedVec::from_available(memory);
let mut num = 0;
// Push mutable ref, not 'static, Copy nor Clone!
vector.push(&mut num);
*vector[0] = 42;
drop(vector); assert_eq!(num, 42); ```
This project is mainly MIT licensed. You may alternatively choose the Unlicense instead in which case the copyright headers signify the parts dedicated to the public domain to the fullest possible extent instead.