> Rust doesn't have nil/null values.

I have to nitpick here: Rust raw pointers (https://doc.rust-lang.org/std/primitive.pointer.html which does note "Working with raw pointers in Rust is uncommon") do have null values. It's not usually a problem since raw pointers can only be dereferenced in unsafe code; most of the time, you will be using a reference wrapped with an Option, which has the same size and same possible values (the compiler knows a reference is never null, so it uses the "missing" null value to represent the None variant of the Option enum).