Rust Memory Management: Ownership vs. Reference Counting

Post by bcjdjsndon » Mon, Apr 27, 2026, 12:29 PM UTC

kibwen wrote: post #17

bcjdjsndon wrote: post #9

Earlier quoted context omitted.

[flagged]

The point of Rust, without counting `unsafe`, is to eliminate memory errors at compile-time. But the point of Rust, when including `unsafe`, is not to entirely eliminate memory errors at compile-time, but to make it feasible to cordon off the unsafe parts into realistically-auditable sections with documented safety invariants. At this it has been dramatically successful, almost beyond anyone's wildest hopes. I have w…

Post by baranul » Mon, Apr 27, 2026, 12:32 PM UTC

kibwen wrote: post #19

baranul wrote: post #8

Rust is becoming less special in this area. Languages such as Dlang, Vlang, and Julia have added optional ownership and borrowing. As these offerings are optional, many can see this as greater programmer freedom to decide what to use for their projects, with languages that are easier to use or read.

It's not a question of support, it's a question of defaults. Rust code exercises a single-ownership discipline by default, and you must opt-in to dynamic multi-ownership (via refcounting or otherwise). In languages that have pervasive dynamic multi-ownership by default (via GC, etc.), enforced single-ownership is instead opt-in, which means that you cannot expect code in the wild to use it. In Rust, you can expect co…

Post by seanalltogether » Mon, Apr 27, 2026, 1:02 PM UTC

    struct Node {
        value: i32,
        children: Vec>>>,
        parent: Option>>>, // Weak breaks parent→child cycle
    }

Post by smallstepforman » Mon, Apr 27, 2026, 1:17 PM UTC

TonyStr wrote: post #13

smallstepforman wrote: post #11

This is all well and dandy for some usage scenarios but breaks in others, eg. scene graphs and GUI's. A scene graph needs 2 mutable references, and has nothing to do with ownership. Same issue exists with GUI's. The pattern that Rust forces is to always request a reference, which incurs a performance penalty while retrieving the same reference again and again and again.

I am not familiar with scene graphs, but what is the problem with borrowing or refcounting? This article showed how you can have multiple mutable references in Rust, even multiple mutable references running in parallel threads.

Post by reorder9695 » Mon, Apr 27, 2026, 1:33 PM UTC

bcjdjsndon wrote: post #21

kibwen wrote: post #17

Earlier quoted context omitted.

The point of Rust, without counting `unsafe`, is to eliminate memory errors at compile-time. But the point of Rust, when including `unsafe`, is not to entirely eliminate memory errors at compile-time, but to make it feasible to cordon off the unsafe parts into realistically-auditable sections with documented safety invariants. At this it has been dramatically successful, almost beyond anyone's wildest hopes. I have w…

> without counting `unsafe`, Well, if you exclude all the bad code people have wrote, c is a safe language... See the point I'm making here? If coders couldn't be trusted multiple times in the past, and we had to invent language level features to correct them, but they still continued to make either the same, or a new, mistakes.... Why is rust any different? I guarantee you we will be complaining about unsafe rust in…