miniblog.

It took me way too long to realise that Arc<Mutex<T>> is basically a way to create multiple &mut T references (with runtime constraints). This means that you can use plain &T and &mut T in the vast majority of your code. Most code doesn't need to care there's a mutex.

Smalltalk has a remarkable method named #become: that allows you to modify all pointers to a given object to point to a different object! https://gbracha.blogspot.com/2009/07/miracle-of-become.html This goes even further than updating instances when a class changes, it's changing instance references.

Is there any way of doing tagged references in safe Rust? I've been looking at tagged pointers (the crate https://docs.rs/tagged-pointer/latest/tagged_pointer/ looks excellent) but it gives you back a raw pointer. I'm not sure if you can create a safe wrapper for references using tagged pointers.