Rust's Zero-Cost Abstractions, What Monomorphization Actually Does to Your Code

"Zero-cost abstractions" is one of Rust's core promises. You can write generic, composable, high-level code and the compiler will produce the same machine code as if you had written the low-level version by hand. Most people accept this claim and move on. It is worth actually understanding the mechanism behind it, because it has real consequences for compile times, binary size, and performance in ways that will eventually surprise you. The Problem Abstractions Usually Create In most languages wi