book/redirects/borrow-and-asref.md

% Borrow and AsRef

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A cheap reference-to-reference conversion. Used to convert a value to a reference value within generic code.

fn is_hello<T: AsRef<str>>(s: T) {
   assert_eq!("hello", s.as_ref());
}

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This chapter does not exist in the second edition. The best place to learn more about this is the Rust documentation.

• In the Rust documentation: convert::AsRef
• In the first edition: Ch 4.10 — Borrow and AsRef