Rust 抱怨我正在编写的方法的生命周期

Question

我正在为学习Rust而苦苦挣扎，终其一生。所以我在网络客户端包装器中制作下面的方法。

pub async fn get_as_bytes<T: serde::Deserialize>(
    &self,
    url: &str,
    headers: Option<HeaderMap>,
) -> Result<T, Box<dyn Error>> {
    let mut req = self.reqwest_client.request(reqwest::Method::GET, url);

    if let Some(hds) = headers {
        req = req.headers(hds);
    }

    let resp: Response = req.send().await?;
    let full = resp.bytes().await?;

    let result = serde_json::from_slice(&full).unwrap();
    Ok(result)
}

当我尝试编译时，我得到了：

error[E0106]: missing lifetime specifier
  --> src/webclient.rs:53:41
   |
53 |     pub async fn get_as_bytes<T: serde::Deserialize>(&self, url: &str, headers: Option<HeaderMap>) -> Result<T, Box<dyn Error>> {
   |                                         ^^^^^^^^^^^ expected named lifetime parameter
   |
help: consider introducing a named lifetime parameter
   |
53 |     pub async fn get_as_bytes<'a, T: serde::Deserialize<'a>>(&self, url: &str, headers: Option<HeaderMap>) -> Result<T, Box<dyn Error>> {
   |                               ^^^           ^^^^^^^^^^^^^^^

error[E0597]: `full` does not live long enough
  --> src/webclient.rs:63:45
   |
63 |         let result = serde_json::from_slice(&full).unwrap();
   |                      -----------------------^^^^^-
   |                      |                      |
   |                      |                      borrowed value does not live long enough
   |                      argument requires that `full` is borrowed for `'static`
64 |         Ok(result)
65 |     }
   |     - `full` dropped here while still borrowed

如何让 &full 成为最后一个，因为我正在尝试 return 它？

Answer 1

只是作为将来的参考发布，而不是删除问题。正如@Shepmaster 在问题的评论中提到的那样，que Lifetime error when creating a function that returns a value implementing serde::Deserialize 解决了这个问题。作为文档，代码将是：

pub async fn get_as_bytes<T: serde::de::DeserializeOwned >(&self, url: &str, headers: Option<HeaderMap>) -> Result<T, Box<dyn Error>> {
        let mut req = self.reqwest_client.request(reqwest::Method::GET, url);

        if let Some(hds) = headers {
            req = req.headers(hds);
        }

        let resp: Response = req.send().await?;
        let full = resp.bytes().await?;

        let result = serde_json::from_slice(&full).unwrap();
        Ok(result)
    }
    ```

Rust 抱怨我正在编写的方法的生命周期

Rust complaining about lifetime on the method I am writing

compiler-errors

lifetime

rust

serde-json