How to avoid fighting the Rust borrow checker

https://qouteall.fun/qouteall-blog/2025/How%20to%20Avoid%20Fighting%20Rust%20Borrow%20Checker

by qouteall • 10 months ago

26 9 10 months ago

qouteall.fun

jurschreuder• 10 months ago

Or just use C++

torginus• 10 months ago

Gottem

runlaszlorun• 10 months ago

Ha... I'll confess "don't use Rust" was my immediate reaction.

Klonoar• 10 months ago

Skill issue.

cwillu3• 10 months ago

It's (mildly) concerning how the answer to complicated ownership situations is (sometimes) to defeat the borrow checker by reimplementing a pointer system that the borrow checker can't check.

db48x2• 10 months ago

Why? Sometimes you don't know how ahead of time how many references to a thing your program will need.

For example, consider a program that reads in a git fast-import stream. The first commit creates a file named README.txt. How many more commits will touch the same path? You’ve no idea, of course, but it could be hundreds of thousands. Do you want hundreds of thousands of individual strings all containing that same filename? That would be fine in the first draft of your program, but in the long term it is too big of a cost to pay (believe me, I know). So you want some kind of pool to store filenames. It could be a grow-only arena, so that you can use plain references, or a mutable pool using reference counting (Arc obviously).

Rust gives you the power to start writing your program using ordinary strings for filenames (or OsStr, obviously), and then later graduate to something both more complicated and more efficient just by swapping out the implementation of one type.

cwillu3• 10 months ago

The article talks about using handles, which reintroduce all the same use-after-free issues that the borrow checker is claimed to solve.

How to avoid fighting the Rust borrow checker

Related Stories