this post was submitted on 15 Nov 2024
168 points (92.4% liked)
Programmer Humor
32472 readers
667 users here now
Post funny things about programming here! (Or just rant about your favourite programming language.)
Rules:
- Posts must be relevant to programming, programmers, or computer science.
- No NSFW content.
- Jokes must be in good taste. No hate speech, bigotry, etc.
founded 5 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Equality in rust is value equality per default, that's what these traits are for. If you want to check pointer equality you'd use the
std::ptr::eqfunction to check if two pointers are equal, which is rather rare in practice. You can also implement thePartialEqtrait yourself if you need custom equality checks.I worked on software at one point that had at it's core a number of "modes" that it switched between. It was, at the time, in the process of migrating from enums and switch/case trees to an inheritance based system.
In practice this meant there was a single instance of "Mode" for each mode which used pointer equality to switch/case on modes like an enum.
To add a new mode (that did nothing) I think I had to change about 6 different places.
Not really related to the pointer thing, but Rust also has pattern matching based on Enums, as they're actually sum-types and not just numbers