Default is mentioned occasionally in the book, but I think it could use its own page.
贡献者指南
技术栈
rust
领域
documentation
议题类型
documentation
难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。
2
预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。
1-3 hours
活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。
stale
清晰度议题是否清楚说明期望改动、验收标准和下一步。
clear
前置要求
Rust basicsUnderstanding of Default trait
新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。
80
研究方向
Add a new page to the Rust by Example book covering the Default trait, including examples of its usage, the `#[derive(Default)]` macro, and discussion of when it is appropriate to use Default versus implementing it manually. Refer to existing pages like those for `From` and `Into` for style and structure. Check the single comment on the issue for any additional context or suggestions.
Add examples of Default and when to/not use it · rust-lang/rust-by-example#1256 | Good First Issue
