Tell me more about the Rust like feature in Swift with a borrow checker
Asked on 08/03/2024
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The Rust-like feature in Swift that includes a borrow checker is part of the new concurrency safety guarantees introduced in Swift 6. This feature aims to turn data races, which are typically runtime issues, into compile-time errors, thereby improving the correctness and safety of your code.
To take advantage of these guarantees, you need to adopt the Swift 6 language mode. This mode introduces full enforcement of data isolation, preventing accidental sharing of state between tasks and actors, which can lead to data races. This is particularly useful for refactoring or adding new functionality without introducing new concurrency bugs.
Swift's borrow checker works by ensuring that there are no simultaneous attempts to mutate or consume a value. This is similar to Rust's borrow checker, which ensures that references to data do not outlive the data they point to and that mutable references are not aliased. In Swift, borrowing a value means asserting that nobody else can consume or mutate it, which is crucial for maintaining data race safety.
For more details on this feature, you can refer to the session Explore Swift performance (17:00).
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