this post was submitted on 12 Jun 2023
492 points (100.0% liked)
Technology
37739 readers
500 users here now
A nice place to discuss rumors, happenings, innovations, and challenges in the technology sphere. We also welcome discussions on the intersections of technology and society. If it’s technological news or discussion of technology, it probably belongs here.
Remember the overriding ethos on Beehaw: Be(e) Nice. Each user you encounter here is a person, and should be treated with kindness (even if they’re wrong, or use a Linux distro you don’t like). Personal attacks will not be tolerated.
Subcommunities on Beehaw:
This community's icon was made by Aaron Schneider, under the CC-BY-NC-SA 4.0 license.
founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
When you create an instance of a struct and assign it to a variable or field of another struct, that variable becomes the owner of that value. When you assign it to some other variable or pass it to a function that takes ownership, ownership will move. Otherwise, you will borrow. But there will always only be one owner for each value. That way you know exactly when to free up memory: whenever the owner is dropped.
So then when you say "most operations on data will be done by the owner of that data", do you mean ownership-taking functions? In my head a variable is like a bin, so it's odd to think of it doing any "operations" other than holding.
No, I phrased that poorly. What I meant is that if you have a struct that has some field (it owns that data), your operations on that data will be methods of that struct, and not some other struct that happens to have a reference to that struct. The latter is something people tend to do in OO languages like Java. In Rust, if a function accesses data, you usually "freshly" borrow from the owner of that data and pass it as argument to that function instead of relying on some "hidden" references somewhere in hidden in an object. Borrows will almost always be short-lived.
I don't know if any of this makes sense, I'm sorry for the bad explanation. It might make more sense if you play with Rust yourself.