Option, Result, match, if let, the ? operator, custom error types and panic versus recoverable errors.
40 cards · basic cards · AI-written, checked twice. Edit anything.
- What does the Option enum represent in Rust?
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A value that may or may not be present, with variants Some(T) for a value and None for absence.- What are the two variants of the Option enum?
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Some(T) for a present value, and None for absence.- What does Option::unwrap() do?
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Returns the inner value T if it is Some(T), or panics if it is None.- What does Option::unwrap_or(default) do?
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Returns the inner value if Some(T), or the provided default value if None.- What does Option::is_some() return?
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true if the Option is Some(T), false if it is None.- What does Option::is_none() return?
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true if the Option is None, false if it is Some(T).- What does Option::map(f) do?
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Applies function f to the inner value if Some(T), returning Some(result), or returns None unchanged.- What does Option::filter(predicate) do?
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Returns Some(T) if the predicate is true, or None if the predicate is false or the Option is already None.- What does Option::flatten() do?
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Converts Option<Option<T>> to Option<T>, collapsing nested Options.- How do you use if let to destructure Some in an Option?
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if let Some(x) = option { /* use x */ } matches and binds the inner value.- What does the Result enum represent in Rust?
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A value that is either a success (Ok(T)) or an error (Err(E)), used for recoverable errors.- What are the two variants of the Result enum?
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Ok(T) for a successful value, and Err(E) for an error.- What does Result::unwrap() do?
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Returns the inner Ok(T) value, or panics if the Result is Err(E).- What does Result::unwrap_or(default) do?
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Returns the Ok(T) value, or the provided default value if Err(E).- What does Result::unwrap_err() do?
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Returns the inner Err(E) value, or panics if the Result is Ok(T).
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