Call for testing: Restricting trait implementability and field mutability
Summary
Rust's Inside Rust blog announces testing for RFC 3323 'Restrictions' on nightly Rust, introducing two features: impl_restriction (restricting trait implementations) and mut_restriction (restricting field mutations). The post provides examples, discusses how these features compare to the sealed trait pattern, and invites developers to test, provide feedback, and help refine the syntax. It also outlines how to participate and what remains unresolved.