Mon, 04 May 2026 18:21:52 +0000

The Hidden Feature That Makes Rust Code Speed Begin to Shock You When people talk about Rust, speed is almost always top of the list. High performance, memory safety without a garbage collector, and zero-cost abstractions—that’s why Rust has become a favorite for systems programming, gaming engines, and performance-critical applications. But there’s a behind-the-scenes trick that doesn’t get as much spotlight as it should: Rust’s Horn Iterator pattern and its lazy evaluation model. Tracking down this hidden beastly performance boost can explain why Rust code often shocks developers and benchmarks alike. ### What Is Rust’s Horn Iterator and Why Should You Care? At the heart of Rust’s iterator aesthetic lies the Horn Iterator pattern—a lazy, composable way to process data streams efficiently. Unlike eager enumeration, which computes values immediately, Horn iterators defer actions until they’re truly needed. This laziness eliminates intermediate data structures, reduces memory overhead, and allows for optimal chaining of transformations.