Rust’s ndarray crate is a powerful foundation for numerical and scientific computing — but just like with any data‑heavy workload, performance depends heavily on how you write your loops.
To explore this, I built a small educational demo that evaluates 10 different techniques for adding two 2D matrices (Array2
Rust provides strong guarantees about memory safety, alignment, and the behavior of references. However, when you step into the world of low‑level programming — manual allocation, pointer arithmetic, and raw memory manipulation — it becomes your job to uphold these guarantees. One interesting challenge: Can we intentionally place a u32 at an odd address and still read it safely?
Rust is very strict about memory safety, especially when it comes to unaligned data. If you’ve ever worked with byte buffers, binary protocols, FFI, or #[repr(packed)] structs, you’ve probably run into an error like: “error: Reference to field of packed struct is unaligned”
This is Rust politely telling you: “Stop! Creating a reference here would be undefined behavior.”
In this article, we’ll look at why this happens and how Rust’s addr_of! and addr_of_mut! macros let you safely work with potentially unaligned or unsafe memory locations without creating invalid references.