miniblog.

Linux historically used magic numbers to recognise structs being used incorrectly with void pointers. These have been increasingly replaced with type-safe macros: https://lwn.net/SubscriberLink/915163/ba83480903b82cb8/ Some of the original files were unchanged from the 90s!

This article discusses how you often need #'foo rather than foo in Clojure code so you can redefine foo whilst testing your app interactively: https://srasu.srht.site/var-evaluation.html Perhaps function pointers should evaluate to themselves? I wonder if there's a language solution here.

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.