Note: the ᐸᐳ characters used below are Canadian Aboriginal syllabics because Lemmy devs haven’t fixed broken input sanitization yet.

Well, getters are not an official concept in Rust. You can do whatever works best in your case.

Just worth pointing out that a method with a return value of OptionᐸVecᐸStringᐳᐳ wouldn’t be really a getter, as you must be constructing values, or moving ownership, or cloning. None of these actions conceptually belong to a getter.

Also, you should be clear on the what the Option abstraction means. Does it mean the vector is empty? Does it mean the vector does not exist or some sort of null (FFI ore serialization contexts)? And make sure the code does what you expect it to do.

Why not &[String]?

You may be better off with &[String] as a read-only view of Vec<String>. To get &[&str] I think you need to create a new collection to hold the &str values. (String and &str have different memory representations.) But the choice depends on what you want to do - maybe providing &str values adds a convenience that is worth creating a second collection.

For the Option case I would go with Option<&[String]>. My understanding is that Option<&T> is the same size as &T for any T so an owned Option wrapper is zero-cost. If the reference pointer is null then Rust interprets that as None. Besides you usually want ownership of an Option so you can map it or whatever else you want to do.