Rust 1.100 introduces the empty type (! or never) to all type annotations, not just function return types. The article explains the key distinction between the empty type and the bottom type: Rust's ! requires no subtyping support, while the bottom type relies on subtyping to be used anywhere.
Background
Rust has supported the never type (!) as a function return type for years, but the recent change in Rust 1.100 extends its use to all type annotation contexts. This touches on foundational type theory concepts relevant to systems programming language design.
- Source
- Lobsters
- Published
- Sep 9, 2026 at 05:23 AM
- Score
- 6.0 / 10