[pdimitar]

> You have to consciously talk yourself out of that if you want to be productive.

That's 100% correct but there's one problem: how do you write down your future improvement opportunities?

Skip 2 optimizations here, 3 optimizations there and after 30 PRs you can easily have notes spanning 100 bullet points on what to optimize one day in the future Soon™.

I am still not at what I'd call an expert level in Rust -- and the skill ceiling is quite high -- so maybe with time I'd start to automatically spot these optimization opportunities?

But before I am at that level I'd prefer to either keep hugely long notes or, ideally, have a tool recommend optimizations to me.

[SAI_Peregrinus]

The simplest tool is to just grep for various constructs that copy or allocate. Clippy, the Rust linter, will find some of these (as well as other issues, some of which tend to cause performance problems).

The better tool is to profile the code, then optimize hotspots. There's a Rust Performance Book with a list of profilers known to work with Rust programs[1]. Rustc does support Profile Guided Optimization[2] which is often pretty good at speeding up the output even without any code changes.

[1] https://nnethercote.github.io/perf-book/profiling.html [2] https://doc.rust-lang.org/rustc/profile-guided-optimization....

[pdimitar]

Helpful links, thank you!

> The simplest tool is to just grep for various constructs that copy or allocate.

Do you happen to have a curated list somewhere?

[SAI_Peregrinus]

For allocations (more expensive in many cases) the Rust container cheat sheet[1] is helpful. Box, Vec, Rc, Arc, and Mutex are the standard types which allocate.

Not sure of a list for things that copy their data. The Clone trait is the obvious one, and it requires calling clone() to make the copy. EG `val.clone()`. So searching for `.clone()` will get you those. But other things like to_string are expensive, and From/Into are sometimes expensive.

[1] https://docs.google.com/presentation/d/1q-c7UAyrUlM-eZyTo1pd...