Default 特征

Default 特征会为类型生成默认值。

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  • 系统可以直接实现它，也可以通过 #[derive(Default)] 派生出它。
  • A derived implementation will produce a value where all fields are set to their default values.
    • 这意味着，该结构体中的所有类型也都必须实现 Default。
  • 标准的 Rust 类型通常会以合理的值（例如 0“” `等）实现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.