Rust format!() Macro Explained: When to Use It (and When Not To)
Using `format!` inside loops in Rust looks harmless — but it can silently destroy performance.
In this video, we debug why `format!` inside loops is expensive, how it causes repeated heap allocations, and what Rust actually does under the hood.
You’ll learn:
• Why `format!` allocates every iteration
• How this impacts tight loops and hot paths
• Common real-world scenarios where this bug appears
• Better Rust patterns to avoid unnecessary allocations
• When `format!` is fine — and when it’s not
This is not beginner Rust.
This video is for developers who already write Rust and want to debug real performance issues.
If you’re transitioning to Rust or optimizing production code, this is a must-watch.
#rust #rustlang #performance #optimization #debugging #systemsprogramming