PolyWolfPolyWolf@treehouse.systems
Sep 29, 2026, 3:32 PMNew blog post: "Pining for Arc Downcasting in Rust"
https://wolfgirl.dev/blog/2026-09-29-pining-for-arc-downcasting-in-rust/
Replies
Verity :transHaskell::verifiedtransfem:monoidmusician@tech.lgbtSep 29, 2026, 4:03 PM@PolyWolf i don't really know what i'm talking about, but is this a little bit like https://doc.rust-lang.org/std/sync/struct.MappedRwLockReadGuard.html ? but without
RwLock? :neobot_flop_blep:- PolyWolfPolyWolf@treehouse.systemsSep 29, 2026, 4:12 PM
@monoidmusician kinda!! those look like they are useful for patterns where you want to immediately drop the lock if you fail to convert. that's still possible without them, just a little uglier code-wise. type signature for projections is the same tho ya
- Verity :transHaskell::verifiedtransfem:monoidmusician@tech.lgbtSep 29, 2026, 4:16 PM
@PolyWolf it says it returns self back in the Err case?
- PolyWolfPolyWolf@treehouse.systemsSep 29, 2026, 4:18 PM
@monoidmusician i am silly, misread, ignore what i said then :P
- Verity :transHaskell::verifiedtransfem:monoidmusician@tech.lgbtSep 29, 2026, 4:19 PM
@PolyWolf hehe okay :3
Sososgued@pouet.chapril.orgOct 1, 2026, 7:56 AM@PolyWolf just FYI what you're doing at the end looks a of like what yoke does. I think it solves your exact problem: https://crates.io/crates/yoke