方法for_each存在，但使用StreamDeckSocket时不满足特征界限。

Question

我正在尝试使用浮甲板-rs机箱，我很难让示例代码正常工作。

我的实现基本上就是给出的具体例子：

use futures::future::Future;
use std::env;
use streamdeck_rs::registration::*;
use streamdeck_rs::socket::StreamDeckSocket;

//the fields of these structs doesn't matter
struct GlobalSettings {}
struct ActionSettings {}
struct MessageToSd {}
struct MessageFromSd {}

fn register() {
    let params = RegistrationParams::from_args(env::args()).unwrap();
    let connect =
        StreamDeckSocket::<GlobalSettings, ActionSettings, MessageFromSd, MessageToSd>::connect(
            params.port,
            params.event,
            params.uuid,
        );
    tokio::run(
        connect
            .map_err(|e| println!("connection failed: {:?}", e))
            .and_then(|socket| {
                socket
                    .for_each(|message| println!("recieved: {:?}", message))
                    .map_err(|e| println!("read error: {:?}", e))
            }),
    );
}

我的错误消息根据我要导入的内容进行更改，但它始终是“方法for_each存在但以下特征边界不满足”的变体。对于我现在列出的导入，我的错误消息是：

error[E0599]: no method named `for_each` found for type `streamdeck_rs::socket::StreamDeckSocket<GlobalSettings, ActionSettings, MessageFromSd, MessageToSd>` in the current scope
  --> src/main.rs:37:35
   |
37 |         .and_then(|socket| socket.for_each(|message| println!("recieved: {:?}", message))
   |                                   ^^^^^^^^
   |
   = note: the method `for_each` exists but the following trait bounds were not satisfied:
           `&mut streamdeck_rs::socket::StreamDeckSocket<GlobalSettings, ActionSettings, MessageFromSd, MessageToSd> : std::iter::Iterator`

我可以导入future::Stream

use streamdeck_rs::registration::*;
use streamdeck_rs::socket::StreamDeckSocket;
use std::env;
use futures::future::Future;
use futures::Stream;
//rest same as before

我得到了一个错误：

error[E0599]: no method named `for_each` found for type `streamdeck_rs::socket::StreamDeckSocket<GlobalSettings, ActionSettings, MessageFromSd, MessageToSd>` in the current scope
  --> src/main.rs:37:35
   |
37 |         .and_then(|socket| socket.for_each(|message| println!("recieved: {:?}", message))
   |                                   ^^^^^^^^
   |
   = note: the method `for_each` exists but the following trait bounds were not satisfied:
           `&mut streamdeck_rs::socket::StreamDeckSocket<GlobalSettings, ActionSettings, MessageFromSd, MessageToSd> : futures::stream::Stream`
           `&mut streamdeck_rs::socket::StreamDeckSocket<GlobalSettings, ActionSettings, MessageFromSd, MessageToSd> : std::iter::Iterator`
           `streamdeck_rs::socket::StreamDeckSocket<GlobalSettings, ActionSettings, MessageFromSd, MessageToSd> : futures::stream::Stream`



warning: unused import: `futures::Stream`

注意有关未使用的导入的警告。

因为StreamDeckSocket是在机箱中定义的，所以我不能在它上实现任何特性。

我知道这个问题以几种形式存在，但据我所知，这些答案只有在我使用的板条箱中缺少特性实现时才适用。

Answer 1

示例代码片段不太正确，但非常接近：

• 需要#[derive(Deserialize, Debug)]的结构
• 根据文献资料，传递给for_each的闭包类型是错误的。

以下是汇编：

use futures::future::Future;
use futures::stream::Stream;
use serde::Deserialize;
use std::env;
use streamdeck_rs::registration::*;
use streamdeck_rs::socket::StreamDeckSocket;

#[derive(Deserialize, Debug)]
struct GlobalSettings {}

#[derive(Deserialize, Debug)]
struct ActionSettings {}

#[derive(Deserialize, Debug)]
struct MessageToSd {}

#[derive(Deserialize, Debug)]
struct MessageFromSd {}

fn main() {
    let params = RegistrationParams::from_args(env::args()).unwrap();
    let connect =
        StreamDeckSocket::<GlobalSettings, ActionSettings, MessageFromSd, MessageToSd>::connect(
            params.port,
            params.event,
            params.uuid,
        );
    tokio::run(
        connect
            .map_err(|e| println!("connection failed: {:?}", e))
            .and_then(|socket| {
                socket
                    .for_each(|message| {
                        println!("recieved: {:?}", message);
                        Ok(())
                    })
                    .map_err(|e| println!("read error: {:?}", e))
            }),
    );
}