A start to general async read trait

But this might also be totally not worth it as it is out of scope.
Also, it is complex

src/lib.rs

@@ -188,6 +188,8 @@ mod connect_options;
 mod mqtt_handler;
 mod util;
 
+mod mqtt_async_traits;
+
 #[cfg(feature = "smol")]
 pub mod smol;
 #[cfg(feature = "sync")]

src/mqtt_async_traits.rs

@@ -0,0 +1,79 @@
+use futures::Future;
+use tokio::io::AsyncReadExt;
+
+pub trait AsyncMqttRead {
+    fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> impl Future<Output = std::io::Result<usize>> + Send + Sync;
+
+    fn read_exact<'a>(&'a mut self, buf: &'a mut [u8]) -> impl Future<Output = std::io::Result<()>> + Send + Sync;
+
+    fn take()
+
+    // async fn read_exact_into_vec(&mut self, limit: u64) -> std::io::Result<Vec<u8>>;
+}
+
+// #[cfg(feature = "a")]
+// impl<S> MqttAsyncRead for S where S: futures::AsyncReadExt + Unpin {
+//     fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> impl Future<Output = std::io::Result<usize>> {
+//         self.read(buf)
+//     }
+// }
+
+#[cfg(feature = "tokio")]
+impl<S> AsyncMqttRead for S where S: tokio::io::AsyncReadExt + Unpin + Send + Sync {
+    fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> impl Future<Output = std::io::Result<usize>> + Send + Sync {
+        self.read(buf)
+    }
+
+    fn read_exact<'a>(&'a mut self, buf: &'a mut [u8]) -> impl Future<Output = std::io::Result<()>> + Send + Sync{
+        async{
+            self.read_exact(buf).await.map(|_| ())
+        }
+    }
+
+    // async fn read_exact_into_vec(&mut self, limit: u64) -> std::io::Result<Vec<u8>> {
+    //     let mut buffer = Vec::with_capacity(limit as usize);
+
+    //     self.take(limit).read_to_end(&mut buffer).await?;
+
+    //     Ok(buffer)
+    // }
+}
+
+
+pub trait MqttAsyncWrite {
+    async fn flush(&mut self) -> Result<(), std::io::Error>;
+
+    async fn write<'a>(&'a mut self, buf: &'a [u8]) -> std::io::Result<usize>;
+
+    async fn write_all<'a>(&'a mut self, buf: &'a [u8]) -> std::io::Result<()>;
+}
+
+#[cfg(feature = "a")]
+impl<S> MqttAsyncWrite for S where S: futures::AsyncWriteExt + Unpin{
+    async fn flush(&mut self) -> Result<(), std::io::Error> {
+        self.flush().await
+    }
+
+    async fn write<'a>(&'a mut self, buf: &'a [u8]) -> std::io::Result<usize> {
+        self.write(buf).await
+    }
+
+    async fn write_all<'a>(&'a mut self, buf: &'a [u8]) -> std::io::Result<()> {
+        self.write_all(buf).await
+    }
+}
+
+#[cfg(feature = "tokio")]
+impl<S> MqttAsyncWrite for S where S: tokio::io::AsyncWriteExt + Unpin{
+    async fn flush(&mut self) -> Result<(), std::io::Error> {
+        self.flush().await
+    }
+
+    async fn write<'a>(&'a mut self, buf: &'a [u8]) -> std::io::Result<usize> {
+        self.write(buf).await
+    }
+
+    async fn write_all<'a>(&'a mut self, buf: &'a [u8]) -> std::io::Result<()> {
+        self.write_all(buf).await
+    }
+}