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.
user
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.
assistant
Would you recommend this approach for arrays of sizes in the millions? What other approaches could I take and what would their advantages and disadvantages be with respect to the options given above?
user
As for the first approach, printing an array line by line using a for loop as in the first example, it would work fine for arrays of sizes in the millions. The complexity of the algorithm is O(n), where n is the size of the array, which means it will take n steps to process the entire array. This means that if the size of the array is very large, the operation might take a considerable amount of time, but it's still a viable option for arrays of millions of elements.

Other approaches to consider for printing large arrays include:

Parallel processing: You could divide the array into smaller chunks and process them in parallel. This will speed up the processing time. However, parallel processing requires more memory and might be more complicated to implement.

Streaming: Instead of processing the entire array at once, you could stream the elements one by one and process them as they arrive. This would reduce the memory requirements, but the processing time might be slightly longer as it requires additional I/O operations.

Using libraries: There are libraries available that can help you process large arrays in a more efficient way. For example, Apache Arrow provides a fast and memory-efficient data structure for processing large arrays of data.

In conclusion, the approach of printing an array line by line using a for loop is a good option for arrays of millions of elements, but there are other options available that might be more suitable for your specific use case depending on your requirements such as memory, processing time, and complexity.
assistant