How do I find the index of an element in an array, vector or slice?

Question

I need to find an index of an element in a vector of strings. This is what I got so far:

fn main() {
    let test: Vec = vec![
        \"one\".to_s         


        

Answer 1

TLDR Use an iterator with the position method, the Rust docs shows a good example.

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No, it's because indices are usize, not i32. In fact, i32 is completely inappropriate for this purpose; it may not be large enough, and there's no reason for it to be signed. Just use usize.

Some other notes: calling to_string() is not free, and you don't need it for the comparison; you can compare string slices just fine!

Also, if you really want to turn a usize into an i32, you can do that with a cast: x as i32, though this will not produce an error on over- or under-flow (i.e. the result may be negative).

All that said, as noted in Mathieu David's answer, there's a position method on iterators that does what you want.