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Flattening Rust’s learning curve

(corrode.dev)
451 points birdculture | 1 comments | 13 May 25 22:25 UTC | HN request time: 0.206s | source
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the__alchemist ◴[14 May 25 17:16 UTC] No.43986975[source]▶
I seem to have eased into a rust programming style that dodges these, perhaps at the cost of some optimizations. Using the first example, for example (The article suggests this): Don't return an `&str`; use those for transient things only like function parameters; not for struct fields or returned types.

I'm starting to wonder what I'm missing out by doing this. Not addressed in the article: Any tips for using the more abstract features, like Cow etc? I hit a problem with this today, where a lib used Cow<&str> instead of String, and the lifetime errors bubbled up into my code.

edit: I found this amusing about the article: They demo `String` as a param, and `&str` as a return type for triggering errors; you can dodge these errors simply by doing the opposite!

replies(3): >>43987394 #>>43987527 #>>43987752 #
1. steveklabnik ◴[14 May 25 18:32 UTC] No.43987752[source]▶
> I'm starting to wonder what I'm missing out by doing this.

It depends. In some cases, you aren't missing anything. In others, you may lose a bit of efficiency by doing some otherwise un-needed copying. Depending on what you're doing that may be irrelevant.

> Any tips for using the more abstract features, like Cow etc? I hit a problem with this today, where a lib used Cow<&str> instead of String, and the lifetime errors bubbled up into my code.

You can do the same thing as you do with &str by calling into_owned on the Cow, you'd get a String back.