How to access a elements of a struct of type array

Question

I created the following struct

pub const BUCKET_SIZE: usize = 4;

pub const FINGERPRINT_SIZE: usize = 1;

pub struct Fingerprint ([u8; FINGERPRINT_SIZE]);

impl Fingerprint {
    pub fn new(bytes: [u8; FINGERPRINT_SIZE]) -> Fingerprint {
        return Fingerprint(bytes);
    }
}

pub struct Bucket ([Fingerprint; BUCKET_SIZE]);

impl Bucket {
    pub fn new(fingerprints: [Fingerprint; BUCKET_SIZE]) -> Bucket {
        Bucket(fingerprints)
    }
    pub fn insert(&self, fp: Fingerprint) -> bool {
        for i in 0..BUCKET_SIZE {



            //HERE IS THE ERROR
            if (self[i as usize] == 0) {
                self[i as usize] = fp;
                return true;
            }



        }
        return false;
    }
}

When trying to compile it i get the following error

error: cannot index a value of type `&bucket::Bucket`

Does it make more sense to make Buckets hold a property fingerprints instead?

Answer 1

The type Bucket is a tuple struct with one field, which you can access with .0.

So you can change the code to:

        if (self.0[i as usize] == 0) {
            self.0[i as usize] = fp;
            return true;
        }

You will also need to change the function argument from &self to &mut self so that you can mutate the fields of self.