CODEWITHSUNDEEP
rust
Evan Schwartzentruber
Evan Schwartzentruber

Reputation: 556

Is there any way to specify a struct's attribute as a function's parameter?

Here is the struct Area that I am using for a Snake program:

struct Area {
    max_x: usize,
    max_y: usize,

    arr: Vec<Vec<&'static str>>
}

And here is the function that uses the arr attribute from the struct Area:

fn refresh(area: &Area) {
    println!("{:?}", area.arr)
}

Since it only needs that one attribute from the struct, I was hoping that I could have the parameter be that one named attribute so that I wouldn't have to write as much. It would look like this (This produces an error):

fn refresh(array: &Area.arr) {
    println!("{:?}", array)
}

Is there any workaround to doing something similar to this?

Upvotes: 2

Views: 467

Answers (1)

frankenapps
frankenapps

Reputation: 8331

Yes, you can change the signature of your refresh function like so

fn refresh(area_arr: &Vec<Vec<&'static str>>) {
    println!("{:?}", area_arr)
}

and then you can call it like this

refresh(&your_area_instance.arr);

Here is a full code example

struct Area {
    max_x: usize,
    max_y: usize,

    arr: Vec<Vec<&'static str>>
}

fn main() {
    let area_instance = Area {
        max_x: 20,
        max_y: 20,
        arr: vec![
            vec![&"test1_1", &"test1_2"],
            vec![&"test2_1", &"test2_2"],
        ]
    };
    refresh(&area_instance.arr);
}

fn refresh(area_arr: &Vec<Vec<&'static str>>) {
    println!("{:?}", area_arr)
}

and a Playground link.

Upvotes: 4

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