from_bytes_or_zeroed

一个从任意字节数组切片中读取整数的crate

lib.rs:

from_bytes_or_zeroed 是一个crate，用于从任意长度的字节数组切片中创建整数。

使用方法

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));

动机

这个crate的创建是因为在安全的Rust中实现这个操作[prim@u64]比使用不安全的操作慢得多。

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