我们可以自动导出用户定义的特征吗? [英] Can we automatically derive a user-defined trait?

问题描述

我有一个这样的结构

#[derive(CustomTrait)]
struct Sample {
    v: Vec<u8>,
}

我的性格是这样的

trait CustomTrait {...}

我可以做以上的事情吗?它为我抛出了一个错误.

Can I do the above stuff? It threw an error for me.

我想要类似于 Clone 特性的东西.这可以用 Rust 实现吗?

I want something similar to the Clone trait. Is this possible with Rust?

推荐答案

#[derive(Foo, Bar)] 是 #[derive_Foo] #[derive_Bar]，所以可以像 #[derive_Clone] 一样实现你自己的装饰器属性，但这需要你编写一个编译器插件，它不是 Rust 的稳定部分，将在 1.0 中不稳定(因此在稳定版和 Beta 版中不可用).

#[derive(Foo, Bar)] is sugar for #[derive_Foo] #[derive_Bar], so it is possible to implement your own decorator attribute in the same way as #[derive_Clone] is, but this requires you to write a compiler plugin, which is not a stable part of Rust and will not be stable in 1.0 (and will thus be unavailable in the stable and beta channels).

书中有一些关于此类问题的文档， 但并不多;你基本上是靠自己的.

There is a little documentation on such matters in the book, but not much; you’re largely on your own with it.

请记住，您在那个阶段实际可以做的事情是有限的；您只能访问结构定义，并且对提到的实际类型一无所知.这非常适合内置 #[derive] 支持的所有特征，但不适用于许多其他特征.

Bear in mind that what you can actually do at that stage is limited; you have access to the struct definition only, and know nothing about the actual types mentioned. This is a good fit for all of the traits for which #[derive] support is built in, but is not for many other traits.

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