Is it better for functions to own their parameters?

[scottmcm]

@weiying-chen

Does this advice apply to function arguments?

Structs are more like function return values than function parameters.

Reusing one of my previous posts on this question:

Returning strings: `String` vs. `&str`

Here's my Rust 101 rules for this: "&str for parameters; String for return types". This always works, and has no borrowck complications, but is sometimes inefficient. the small tweak to add "If you always need to to_owned/to_string the &str parameter, change it to a String parameter". That's more efficient when your caller happens to already have a String, no less efficient if they don't, and still doesn't require thinking about lifetimes. if you're always returning a substring of on…