Default 特徵

Default 特徵會產生型別的預設值。

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Speaker Notes

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  • 這可以直接實作,也可以透過 #[derive(Default)] 衍生得出。
  • A derived implementation will produce a value where all fields are set to their default values.
    • 也就是說,該結構體中的所有型別也都必須實作 Default
  • 標準的 Rust 型別通常會以合理的值 (例如 0"" 等等) 實作 Default
  • The partial struct initialization works nicely with default.
  • The Rust standard library is aware that types can implement Default and provides convenience methods that use it.
  • The .. syntax is called struct update syntax.