Slices

Let’s add another number to our array. Can you find the bug?

The bug is that our type still says that the array should have 5 values, but it has 6. So, you dutifully oblige the compiler and update the type. All well and good. But let’s go back to that sum function exercise. Assuming you did the bonus, you probably ended up with a type signature that looks like:

So, you think to yourself, I’ll just update that to be 6 instead of 5. But what if you want to sum more than one array, and they’re different sizes? Having to define a sum_5, sum_6, and so on seems pretty bad.

Fortunately, Rust isn’t that cruel. ...