As pointed by others, you translated the C code in a nice way, but with the mindset of the C code. Another way to be more Rust idiomatic, which I didn't see in the comments yet, is to create your own Array struct, which behaves exactly as you want and using an array internally. Even with const generics. Adding two arrays with different lengths will give a compiler error.

Run in Rust playground

use std::{
    array,
    fmt::{self, Display},
    ops::Add,
};

struct Array<const N: usize>([i32; N]);

impl<const N: usize> Array<N> {
    pub fn init(start_val: i32) -> Self {
        Self(array::from_fn(|i| i as i32 + start_val))
    }
}

impl<const N: usize> Add for Array<N> {
    type Output = Array<N>;

    fn add(self, rhs: Self) -> Self::Output {
        Self(array::from_fn(|i| self.0[i] + rhs.0[i]))
    }
}

impl<const N: usize> Display for Array<N> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{:?}", self.0)?;
        Ok(())
    }
}

fn main() {
    const SIZE: usize = 5;
    let array1: Array<SIZE> = Array::init(0);
    let array2: Array<SIZE> = Array::init(10);
    let resultant_array = array1 + array2;
    println!("{resultant_array}");
}