How can i list out the contents of an array line by line using the rust programing language
for example the array [1, 2] when inputed would return
1
2
the code needs to be fast.
The following rust code can be used to print an array line by line. 
I've wrapped it in a main function for easy execution:

```
fn main() {
	let arr:[i32; 2] = [1,2];

	for index in 0..arr.len() {
		println!("{}", arr[index]);
	}
}
```

Output:
```
1
2
```

Please note that the Rust println function can also print the contents of an array directly:
```
fn main() {
	let arr:[i32; 2] = [1,2];
	println!("Array {:?}", arr);
}
```

Output:
```
    Array ["1", "2"]
```

This doesn't match the requirement of printing the output line-by-line as stated in the question. I wanted to mention it, as it's short and easy to remember, and might suffice for debugging purpose. However, if you need the response line-by-line, use the first example.