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…iaskrgr Rollup of 4 pull requests Successful merges: - rust-lang#116594 (Fix `std::convert::TryFrom` doc) - rust-lang#116741 (Document `string_deref_patterns` feature) - rust-lang#116748 (Fix a spot I wrote the wrong word) - rust-lang#116753 (add 'Onur Özkan' to .mailmap) r? `@ghost` `@rustbot` modify labels: rollup
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src/doc/unstable-book/src/language-features/string-deref-patterns.md
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# `string_deref_patterns` | ||
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The tracking issue for this feature is: [#87121] | ||
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[#87121]: https://github.com/rust-lang/rust/issues/87121 | ||
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------------------------ | ||
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This feature permits pattern matching `String` to `&str` through [its `Deref` implementation]. | ||
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```rust | ||
#![feature(string_deref_patterns)] | ||
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pub enum Value { | ||
String(String), | ||
Number(u32), | ||
} | ||
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pub fn is_it_the_answer(value: Value) -> bool { | ||
match value { | ||
Value::String("42") => true, | ||
Value::Number(42) => true, | ||
_ => false, | ||
} | ||
} | ||
``` | ||
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Without this feature other constructs such as match guards have to be used. | ||
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```rust | ||
# pub enum Value { | ||
# String(String), | ||
# Number(u32), | ||
# } | ||
# | ||
pub fn is_it_the_answer(value: Value) -> bool { | ||
match value { | ||
Value::String(s) if s == "42" => true, | ||
Value::Number(42) => true, | ||
_ => false, | ||
} | ||
} | ||
``` | ||
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[its `Deref` implementation]: https://doc.rust-lang.org/std/string/struct.String.html#impl-Deref-for-String |