reqwest 示例 POST 请求未编译

Question

我尝试遵守以下要求示例：

let client = reqwest::Client::new();
let res = client.post("http://httpbin.org/post")
    .body("the exact body that is sent")
    .send()?;

示例编译失败：

error[E0277]: the `?` operator can only be applied to values that implement `std::ops::Try`
  --> src/main.rs:26:15
   |
26 |       let res = client.post("http://httpbin.org/post")
   |  _______________^
27 | |     .body("the exact body that is sent")
28 | |     .send()?;
   | |____________^ the `?` operator cannot be applied to type `impl std::future::Future`
   |
   = help: the trait `std::ops::Try` is not implemented for `impl std::future::Future`
   = note: required by `std::ops::Try::into_result`

error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `std::ops::Try`)
  --> src/main.rs:26:15
   |
11 |  / fn main(){
12 |  |     // gets the api key from env var
13 |  |     let mut key: String = env::var("key").unwrap();
14 |  |     // get the mok key bassically useless but its still useful to prevent tampering
...   |
26 |  |     let res = client.post("http://httpbin.org/post")
   |  |_______________^
27 | ||     .body("the exact body that is sent")
28 | ||     .send()?;
   | ||____________^ cannot use the `?` operator in a function that returns `()`
...   |
49 |  |     //}
50 |  | }
   |  |_- this function should return `Result` or `Option` to accept `?`
   |
   = help: the trait `std::ops::Try` is not implemented for `()`
   = note: required by `std::ops::Try::from_error`

我应该如何解决这个问题？这是过时了吗？我正在使用 Rust 版本 1.47.0

Answer 1

根据错误消息，您正在使用 reqwest 的异步版本。如果我没记错的话，最新版本包含异步和阻塞版本。

为了实际消费 future 并获取其中的值，您需要使用执行器来执行它，例如东京。这可以通过多种方式完成。

最简单的方法是将 tokio = { version = "0.2.22", features = ["macros"] } 添加到您的 Cargo.toml，然后将其添加到 main.rs:

#[tokio::main]
async fn main() {
    let client = reqwest::Client::new();
    let res = client.post("http://httpbin.org/post")
        .body("the exact body that is sent")
        .send().await;
}

请注意，我删除了 ?，因为未来不会解析为 Result 或 Option。

reqwest 示例 POST 请求未编译

reqwest example POST request not compiling

rust

reqwest