//@ We already saw that we can use `Arc` to share memory between threads. However, `Arc` can only provide *read-only*
//@ access to memory: Since there is aliasing, Rust cannot, in general, permit mutation. To implement shared-memory
//@ We already saw that we can use `Arc` to share memory between threads. However, `Arc` can only provide *read-only*
//@ access to memory: Since there is aliasing, Rust cannot, in general, permit mutation. To implement shared-memory