RustTutorials/2.Primitives/3ArraysAndSlices.rs

use std::mem;

// This function borrows a slice
fn analyze_slice(slice: &[i32]){
	println!("first element of the slice: {}", slice[0]);
	println!("the slice has {} elements", slice.len());
}

fn main(){
	//Fixed-size array (type signature is superfluous)
	let xs: [i32; 5] = [1, 2, 3, 4, 5];

	//All elements can be initialized to the same value
	let ys: [i32; 500] = [0; 500];

	//Indexing starts at 0
	println!("first element of the array: {}", xs[0]);
	println!("second element of the array: {}", xs[1]);

	//`len` returns the size of the array
	println!("array size: {}", xs.len());

	//Arrays are stack allocated
	println!("array occupies {} bytes", mem::size_of_val(&xs));

	//Arrays can be automatically borrowed as slices
	println!("borrow the whole array as a slice");
	analyze_slice(&xs);

	//Slices can point to a section of an array
	//They are of the form [starting_index..ending_index]
	//starting_index is the first position in the slice
	//ending_index is one more than the last position in the slice
	println!("borrow a section of the array as a slice");
	analyze_slice(&ys[1 .. 4]);

	//Out of bound indexing causes compile error
	//println!("{}", xs[5]);
}