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20 lines
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20 lines
1,018 B
Markdown
# Option
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Type Option represents an optional value: every Option is either Some and contains a value, or None, and does not.
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Option types are very common in Rust code, as they have a number of uses:
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- Initial values
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- Return values for functions that are not defined over their entire input range (partial functions)
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- Return value for otherwise reporting simple errors, where None is returned on error
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- Optional struct fields
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- Struct fields that can be loaned or "taken"
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- Optional function arguments
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- Nullable pointers
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- Swapping things out of difficult situations
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## Further Information
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- [Option Enum Format](https://doc.rust-lang.org/stable/book/ch10-01-syntax.html#in-enum-definitions)
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- [Option Module Documentation](https://doc.rust-lang.org/std/option/)
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- [Option Enum Documentation](https://doc.rust-lang.org/std/option/enum.Option.html)
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- [if let](https://doc.rust-lang.org/rust-by-example/flow_control/if_let.html)
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- [while let](https://doc.rust-lang.org/rust-by-example/flow_control/while_let.html)
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