[astrange]

Swift has a similar memory model to Rust, except that where Rust forbids things Swift automatically copies them to make it work.

People using other languages appear terrified of reference count slowness for some reason, but it usually works well, and atomics are fast on ARM anyway.

[saagarjha]

It's important to note that while Swift often allows for code similar to Rust to be written, the fact that it silently inserts ARC traffic or copies often means that people are going to write code that do things that Rust won't let them do and realize after the fact that their bottleneck is something that they would never have written in Rust. I wouldn't necessarily call this a language failure, but it's something worth looking out for: idiomatic Swift code often diverges from what might be optimally efficient from a memory management perspective.