"rust""systems-programming""performance"
8 min readRust `impl Trait` vs `dyn Trait`: The Performance Decision You Make Without Knowing It 🦀⚡
In PHP and JavaScript, calling a method is just... calling a method. In Rust, there are two fundamentally different ways to do it — one is free at runtime, one costs a lookup. I didn't know I was choosing between them until I needed to care.
Mar 16, 2026