# Renato Athaydes - How to write fast Rust code (Highlights)

## Metadata
**Cover**:: https://readwise-assets.s3.amazonaws.com/static/images/article3.5c705a01b476.png
**Source**:: #from/readwise
**Zettel**:: #zettel/fleeting
**Status**:: #x
**Authors**:: [[Renato Athaydes]]
**Full Title**:: How to write fast Rust code
**Category**:: #articles #readwise/articles
**Category Icon**:: 📰
**URL**:: [renato.athaydes.com](https://renato.athaydes.com/posts/how-to-write-fast-rust-code.html)
**Host**:: [[renato.athaydes.com]]
**Highlighted**:: [[2021-08-22]]
**Created**:: [[2022-09-26]]
## Highlights
- Naively printing to stdout directly
- Allocating small Vectors on the stack with smallvec
- Iterating bytes of str instead of chars
- Using a faster hashing function like ahash significantly improves the performance of map lookups.
- Profile Guided Optimisation (PGO) is a way for the compiler to get information about how a program is likely to be executed so that it can try to perform more specific optimisations based on that when it re-compiles the same program
- Another tool available to Rust developers to find out hotspots in their applications that require optimisations is
flamegraphs.