Statically allocated membership approximation

Xorfilter

A no_std, no alloc crate for membership approximation.

Quick Start

```rust

const N: usize = 100000; let mut keys = [0;N];

for i in 0..N { keys[i] = i as u64; }

let x = XorFilter::from(keys);

for i in 0..N { x.contains(keys[i]); }

```

Status

No Docs
- Blocking on generic_const_exprs
No serialization
- Blocking on Serde

Why Xorfilter

Other existing implementations need alloc for Vec.

Limitations

Xor Filters are not designed to work with duplicate values. [1]

XorFilter could benefit from some features in const generics that are not yet in nightly.

Reference

[1] [Xor Filters: Faster and Smaller Than Bloom and Cuckoo Filters](https://arxiv.org/abs/1912.08258), Journal of Experimental Algorithmics.