from_bytes_or_zeroed

A crate that reads integers from an arbitrary slice of bytes

lib.rs:

from_bytes_or_zeroed is a crate for creating integers from a slice of bytes of any length.

Usage

use from_bytes_or_zeroed::FromBytesOrZeroed;

// If there are too few bytes the remaining bytes are zeroed.
let a = [1, 2];
let b = [1, 2, 0, 0, 0, 0, 0, 0];
assert_eq!(u64::from_le_bytes_or_zeroed(&a), u64::from_le_bytes(b));

// If there are too many bytes the extra bytes are ignored.
let a = [1, 2, 3, 4, 5, 6];
let b = [1, 2, 3, 4];
assert_eq!(u32::from_le_bytes_or_zeroed(&a), u32::from_le_bytes(b));

Motivation

This crate was created because implementing this operation for [prim@u64] in safe Rust was significantly slower than using unsafe.

test benches::bench_u64_safe    ... bench:       1,509 ns/iter (+/- 29)
test benches::bench_u64_unsafe  ... bench:         644 ns/iter (+/- 8)