mem_cmp

Safe memory comparison between types in Rust.

Documentation

License

This project is released under either:

• MIT License

• Apache License (Version 2.0)

at your choosing.

lib.rs:

Safe memory comparison between types.

Types found in this crate serve as safe wrappers around memcmp operations.

Usage

This crate is available on crates.io and can be used by adding the following to your project's Cargo.toml:

[dependencies]
mem_cmp = "0.1.4"

and this to your crate root:

extern crate mem_cmp;

Comparing Memory

The MemOrd trait provides convenience around the result of a memcmp call by returning an Ordering.

If the only thing that matters is equality, MemEq is also available.

use mem_cmp::*;

let a = [0u8; 256];
let b = [0u32; 64];
let c = [4u32; 64];

assert!(a.mem_eq(&b));
assert!(a.mem_neq(&c));

// Also works with types of different sizes:
assert!(a.mem_neq(&42));

Safety

Generally, comparing memory directly is safe. However, there are cases where undefined behavior may be encountered.

• Types with padding:

  One such case is with types where the inner values are padded for alignment. Such a type would be (u8, u32). It has an alignment of 4 bytes, resulting in 3 bytes of padding between the first value and the second. It's up to the compiler to decide what the byte values are for the padding.