rust - 无法在已实现的方法中序列化结构，因为 "the trait ` serde::Serialize` 未针对 `Self` 实现“

Question

extern crate serde;
extern crate serde_json;

#[macro_use]
extern crate serde_derive;

#[derive(Serialize)]
pub struct MyStruct<'a> {
    pub field1: &'a str,
    pub field2: &'a str,
}

pub trait MyTrait {
    fn payload_to_json(&self) -> String {
        serde_json::to_string(&self)
    }
    fn do_the_thing(&self) {
        println!(payload_to_json(&self));
    }
}

impl MyTrait for MyStruct<'_> {}

fn main() {
    let n = MyStruct {
        field1: "foo"
        field2: "bar"
    }

    n.do_the_thing();
}
// What I'm hoping for: { "field1": "foo", "field2": "bar" }

这给了我以下错误:

error[E0277]: the trait bound `Self: Serialize` is not satisfied
    --> src/main.rs:10:31
     |
10   |         serde_json::to_string(&self)
     |                               ^^^^^ the trait `Serialize` is not implemented for `Self`

我是 Rust 的新手，所以可能会遗漏一些简单的东西；唯一实现 MyTrait 的结构确实有 Serialize已实现(除非我误解了 derived() 的作用)，所以我认为编译器没有被告知 .. 某处。有人可以帮忙吗？

Answer 1

将你的特质绑定(bind)到 Serialize :

pub trait MyTrait: Serialize {
    fn payload_to_json(&self) -> String {
        serde_json::to_string(&self).expect("A valid json")
    }
    fn do_the_thing(&self) {
        println!("{}", self.payload_to_json());
    }
}

Playground