Replaced impl_cast with a new and improved trait

With this trait the impl_cast macros are no longer needed, simplifying
everything.
This commit also improved how the actual casting itself is handled.

Cargo.lock

@@ -76,6 +76,7 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "async-trait",
+ "automation_cast",
  "axum",
  "bytes",
  "console-subscriber",
@@ -84,7 +85,6 @@ dependencies = [
  "eui48",
  "futures",
  "google-home",
- "impl_cast",
  "indexmap 2.0.0",
  "paste",
  "pollster",
@@ -104,6 +104,10 @@ dependencies = [
  "wakey",
 ]
 
+[[package]]
+name = "automation_cast"
+version = "0.1.0"
+
 [[package]]
 name = "axum"
 version = "0.6.20"
@@ -568,8 +572,8 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "async-trait",
+ "automation_cast",
  "futures",
- "impl_cast",
  "serde",
  "serde_json",
  "thiserror",
@@ -761,14 +765,6 @@ dependencies = [
  "unicode-normalization",
 ]
 
-[[package]]
-name = "impl_cast"
-version = "0.1.0"
-dependencies = [
- "quote",
- "syn 2.0.28",
-]
-
 [[package]]
 name = "indexmap"
 version = "1.9.3"

Cargo.toml

@@ -4,20 +4,20 @@ version = "0.1.0"
 edition = "2021"
 
 [workspace]
-members = ["impl_cast", "google-home"]
+members = ["google-home", "automation_cast"]
 
 [dependencies]
+automation_cast = { path = "./automation_cast/" }
 rumqttc = "0.18"
 serde = { version = "1.0.149", features = ["derive"] }
 serde_json = "1.0.89"
-impl_cast = { path = "./impl_cast", features = ["debug"] }
 google-home = { path = "./google-home" }
 paste = "1.0.10"
 tokio = { version = "1", features = ["rt-multi-thread"] }
 dotenvy = "0.15.0"
 reqwest = { version = "0.11.13", features = [
-	"json",
-	"rustls-tls",
+  "json",
+  "rustls-tls",
 ], default-features = false } # Use rustls, since the other packages also use rustls
 axum = "0.6.1"
 serde_repr = "0.1.10"
@@ -28,8 +28,8 @@ regex = "1.7.0"
 async-trait = "0.1.61"
 futures = "0.3.25"
 eui48 = { version = "1.1.0", default-features = false, features = [
-	"disp_hexstring",
-	"serde",
+  "disp_hexstring",
+  "serde",
 ] }
 thiserror = "1.0.38"
 anyhow = "1.0.68"

automation_cast/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "automation_cast"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

automation_cast/src/lib.rs

@@ -0,0 +1,37 @@
+#![allow(incomplete_features)]
+#![feature(specialization)]
+#![feature(unsize)]
+
+use std::marker::Unsize;
+
+pub trait Cast<P: ?Sized> {
+    fn cast(&self) -> Option<&P>;
+    fn cast_mut(&mut self) -> Option<&mut P>;
+}
+
+impl<D, P> Cast<P> for D
+where
+    P: ?Sized,
+{
+    default fn cast(&self) -> Option<&P> {
+        None
+    }
+
+    default fn cast_mut(&mut self) -> Option<&mut P> {
+        None
+    }
+}
+
+impl<D, P> Cast<P> for D
+where
+    D: Unsize<P>,
+    P: ?Sized,
+{
+    fn cast(&self) -> Option<&P> {
+        Some(self)
+    }
+
+    fn cast_mut(&mut self) -> Option<&mut P> {
+        Some(self)
+    }
+}

google-home/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-impl_cast = { path = "../impl_cast" }
+automation_cast = { path = "../automation_cast/" }
 serde = { version = "1.0.149", features = ["derive"] }
 serde_json = "1.0.89"
 thiserror = "1.0.37"

google-home/src/device.rs

@@ -1,4 +1,5 @@
 use async_trait::async_trait;
+use automation_cast::Cast;
 use serde::Serialize;
 
 use crate::errors::{DeviceError, ErrorCode};
@@ -7,43 +8,10 @@ use crate::response;
 use crate::traits::{FanSpeed, HumiditySetting, OnOff, Scene, Trait};
 use crate::types::Type;
 
-// TODO: Find a more elegant way to do this
-pub trait AsGoogleHomeDevice {
-    fn cast(&self) -> Option<&dyn GoogleHomeDevice>;
-    fn cast_mut(&mut self) -> Option<&mut dyn GoogleHomeDevice>;
-}
-
-// Default impl
-impl<T> AsGoogleHomeDevice for T
-where
-    T: 'static,
-{
-    default fn cast(&self) -> Option<&(dyn GoogleHomeDevice + 'static)> {
-        None
-    }
-
-    default fn cast_mut(&mut self) -> Option<&mut (dyn GoogleHomeDevice + 'static)> {
-        None
-    }
-}
-
-// Specialization
-impl<T> AsGoogleHomeDevice for T
-where
-    T: GoogleHomeDevice + 'static,
-{
-    fn cast(&self) -> Option<&(dyn GoogleHomeDevice + 'static)> {
-        Some(self)
-    }
-
-    fn cast_mut(&mut self) -> Option<&mut (dyn GoogleHomeDevice + 'static)> {
-        Some(self)
-    }
-}
-
 #[async_trait]
-#[impl_cast::device(As: OnOff + Scene + FanSpeed + HumiditySetting)]
-pub trait GoogleHomeDevice: AsGoogleHomeDevice + Sync + Send + 'static {
+pub trait GoogleHomeDevice:
+    Sync + Send + Cast<dyn OnOff> + Cast<dyn Scene> + Cast<dyn FanSpeed> + Cast<dyn HumiditySetting>
+{
     fn get_device_type(&self) -> Type;
     fn get_device_name(&self) -> Name;
     fn get_id(&self) -> &str;
@@ -76,26 +44,26 @@ pub trait GoogleHomeDevice: AsGoogleHomeDevice + Sync + Send + 'static {
         let mut traits = Vec::new();
 
         // OnOff
-        if let Some(on_off) = As::<dyn OnOff>::cast(self) {
+        if let Some(on_off) = self.cast() as Option<&dyn OnOff> {
             traits.push(Trait::OnOff);
             device.attributes.command_only_on_off = on_off.is_command_only();
             device.attributes.query_only_on_off = on_off.is_query_only();
         }
 
         // Scene
-        if let Some(scene) = As::<dyn Scene>::cast(self) {
+        if let Some(scene) = self.cast() as Option<&dyn Scene> {
             traits.push(Trait::Scene);
             device.attributes.scene_reversible = scene.is_scene_reversible();
         }
 
         // FanSpeed
-        if let Some(fan_speed) = As::<dyn FanSpeed>::cast(self) {
+        if let Some(fan_speed) = self.cast() as Option<&dyn FanSpeed> {
             traits.push(Trait::FanSpeed);
             device.attributes.command_only_fan_speed = fan_speed.command_only_fan_speed();
             device.attributes.available_fan_speeds = Some(fan_speed.available_speeds());
         }
 
-        if let Some(humidity_setting) = As::<dyn HumiditySetting>::cast(self) {
+        if let Some(humidity_setting) = self.cast() as Option<&dyn HumiditySetting> {
             traits.push(Trait::HumiditySetting);
             device.attributes.query_only_humidity_setting =
                 humidity_setting.query_only_humidity_setting();
@@ -113,7 +81,7 @@ pub trait GoogleHomeDevice: AsGoogleHomeDevice + Sync + Send + 'static {
         }
 
         // OnOff
-        if let Some(on_off) = As::<dyn OnOff>::cast(self) {
+        if let Some(on_off) = self.cast() as Option<&dyn OnOff> {
             device.state.on = on_off
                 .is_on()
                 .await
@@ -122,11 +90,11 @@ pub trait GoogleHomeDevice: AsGoogleHomeDevice + Sync + Send + 'static {
         }
 
         // FanSpeed
-        if let Some(fan_speed) = As::<dyn FanSpeed>::cast(self) {
+        if let Some(fan_speed) = self.cast() as Option<&dyn FanSpeed> {
             device.state.current_fan_speed_setting = Some(fan_speed.current_speed().await);
         }
 
-        if let Some(humidity_setting) = As::<dyn HumiditySetting>::cast(self) {
+        if let Some(humidity_setting) = self.cast() as Option<&dyn HumiditySetting> {
             device.state.humidity_ambient_percent =
                 Some(humidity_setting.humidity_ambient_percent().await);
         }
@@ -137,21 +105,21 @@ pub trait GoogleHomeDevice: AsGoogleHomeDevice + Sync + Send + 'static {
     async fn execute(&mut self, command: &CommandType) -> Result<(), ErrorCode> {
         match command {
             CommandType::OnOff { on } => {
-                if let Some(t) = As::<dyn OnOff>::cast_mut(self) {
+                if let Some(t) = self.cast_mut() as Option<&mut dyn OnOff> {
                     t.set_on(*on).await?;
                 } else {
                     return Err(DeviceError::ActionNotAvailable.into());
                 }
             }
             CommandType::ActivateScene { deactivate } => {
-                if let Some(t) = As::<dyn Scene>::cast(self) {
+                if let Some(t) = self.cast_mut() as Option<&mut dyn Scene> {
                     t.set_active(!deactivate).await?;
                 } else {
                     return Err(DeviceError::ActionNotAvailable.into());
                 }
             }
             CommandType::SetFanSpeed { fan_speed } => {
-                if let Some(t) = As::<dyn FanSpeed>::cast(self) {
+                if let Some(t) = self.cast_mut() as Option<&mut dyn FanSpeed> {
                     t.set_speed(fan_speed).await?;
                 }
             }

google-home/src/fullfillment.rs

@@ -1,14 +1,15 @@
 use std::collections::HashMap;
 use std::sync::Arc;
 
+use automation_cast::Cast;
 use futures::future::{join_all, OptionFuture};
 use thiserror::Error;
 use tokio::sync::{Mutex, RwLock};
 
-use crate::device::AsGoogleHomeDevice;
 use crate::errors::{DeviceError, ErrorCode};
 use crate::request::{self, Intent, Request};
 use crate::response::{self, execute, query, sync, Response, ResponsePayload, State};
+use crate::GoogleHomeDevice;
 
 #[derive(Debug)]
 pub struct GoogleHome {
@@ -29,7 +30,7 @@ impl GoogleHome {
         }
     }
 
-    pub async fn handle_request<T: AsGoogleHomeDevice + ?Sized + 'static>(
+    pub async fn handle_request<T: Cast<dyn GoogleHomeDevice> + ?Sized + 'static>(
         &self,
         request: Request,
         devices: &HashMap<String, Arc<RwLock<Box<T>>>>,
@@ -58,7 +59,7 @@ impl GoogleHome {
             .map(|payload| Response::new(&request.request_id, payload))
     }
 
-    async fn sync<T: AsGoogleHomeDevice + ?Sized + 'static>(
+    async fn sync<T: Cast<dyn GoogleHomeDevice> + ?Sized + 'static>(
         &self,
         devices: &HashMap<String, Arc<RwLock<Box<T>>>>,
     ) -> sync::Payload {
@@ -75,7 +76,7 @@ impl GoogleHome {
         resp_payload
     }
 
-    async fn query<T: AsGoogleHomeDevice + ?Sized + 'static>(
+    async fn query<T: Cast<dyn GoogleHomeDevice> + ?Sized + 'static>(
         &self,
         payload: request::query::Payload,
         devices: &HashMap<String, Arc<RwLock<Box<T>>>>,
@@ -107,7 +108,7 @@ impl GoogleHome {
         resp_payload
     }
 
-    async fn execute<T: AsGoogleHomeDevice + ?Sized + 'static>(
+    async fn execute<T: Cast<dyn GoogleHomeDevice> + ?Sized + 'static>(
         &self,
         payload: request::execute::Payload,
         devices: &HashMap<String, Arc<RwLock<Box<T>>>>,

google-home/src/traits.rs

@@ -16,8 +16,7 @@ pub enum Trait {
 }
 
 #[async_trait]
-#[impl_cast::device_trait]
-pub trait OnOff {
+pub trait OnOff: Sync + Send {
     fn is_command_only(&self) -> Option<bool> {
         None
     }
@@ -32,8 +31,7 @@ pub trait OnOff {
 }
 
 #[async_trait]
-#[impl_cast::device_trait]
-pub trait Scene {
+pub trait Scene: Sync + Send {
     fn is_scene_reversible(&self) -> Option<bool> {
         None
     }
@@ -60,8 +58,7 @@ pub struct AvailableSpeeds {
 }
 
 #[async_trait]
-#[impl_cast::device_trait]
-pub trait FanSpeed {
+pub trait FanSpeed: Sync + Send {
     fn reversible(&self) -> Option<bool> {
         None
     }
@@ -76,8 +73,7 @@ pub trait FanSpeed {
 }
 
 #[async_trait]
-#[impl_cast::device_trait]
-pub trait HumiditySetting {
+pub trait HumiditySetting: Sync + Send {
     // TODO: This implementation is not complete, I have only implemented what I need right now
     fn query_only_humidity_setting(&self) -> Option<bool> {
         None

impl_cast/Cargo.toml

@@ -1,15 +0,0 @@
-[package]
-name = "impl_cast"
-version = "0.1.0"
-edition = "2021"
-
-[lib]
-proc-macro = true
-
-[dependencies]
-syn = { version = "2.0", features = ["extra-traits", "full"] }
-quote = "1.0"
-
-[features]
-debug = [
-] # If enabled it will add std::fmt::Debug as a trait bound to device_traits

impl_cast/src/lib.rs

@@ -1,165 +0,0 @@
-use proc_macro::TokenStream;
-use quote::{format_ident, quote, ToTokens};
-use syn::parse::Parse;
-use syn::{parse_macro_input, Ident, ItemTrait, Path, Token, TypeParamBound};
-
-struct Attr {
-    name: Ident,
-    traits: Vec<Path>,
-}
-
-impl Parse for Attr {
-    fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
-        let mut traits = Vec::new();
-
-        let name = input.parse::<Ident>()?;
-        input.parse::<Token![:]>()?;
-
-        loop {
-            let ty = input.parse()?;
-            traits.push(ty);
-
-            if input.is_empty() {
-                break;
-            }
-
-            input.parse::<Token![+]>()?;
-        }
-
-        Ok(Attr { name, traits })
-    }
-}
-
-/// This macro enables optional trait bounds on a trait with an appropriate cast trait to convert
-/// to the optional traits
-/// # Example
-///
-/// ```
-/// #![feature(specialization)]
-///
-/// // Create some traits
-/// #[impl_cast::device_trait]
-/// trait OnOff {}
-/// #[impl_cast::device_trait]
-/// trait Brightness {}
-///
-/// // Create the main device trait
-/// #[impl_cast::device(As: OnOff + Brightness)]
-/// trait Device {}
-///
-/// // Create an implementation
-/// struct ExampleDevice {}
-/// impl Device for ExampleDevice {}
-/// impl OnOff for ExampleDevice {}
-///
-/// // Creates a boxed instance of the example device
-/// let example_device: Box<dyn Device> = Box::new(ExampleDevice {});
-///
-/// // Cast to the OnOff trait, which is implemented
-/// let as_on_off = As::<dyn OnOff>::cast(example_device.as_ref());
-/// assert!(as_on_off.is_some());
-///
-/// // Cast to the Brightness trait, which is not implemented
-/// let as_on_off = As::<dyn Brightness>::cast(example_device.as_ref());
-/// assert!(as_on_off.is_none());
-///
-/// // Finally we are going to consume the example device into an instance of the OnOff trait
-/// let consumed = As::<dyn OnOff>::consume(example_device);
-/// assert!(consumed.is_some())
-/// ```
-#[proc_macro_attribute]
-pub fn device(attr: TokenStream, item: TokenStream) -> TokenStream {
-    let Attr { name, traits } = parse_macro_input!(attr);
-    let mut interface: ItemTrait = parse_macro_input!(item);
-
-    let prefix = quote! {
-        pub trait #name<T: ?Sized + 'static> {
-            fn is(&self) -> bool;
-            fn cast(&self) -> Option<&T>;
-            fn cast_mut(&mut self) -> Option<&mut T>;
-        }
-    };
-
-    traits.iter().for_each(|device_trait| {
-        interface.supertraits.push(TypeParamBound::Verbatim(quote! {
-            #name<dyn #device_trait>
-        }));
-    });
-
-    let interface_ident = format_ident!("{}", interface.ident);
-    let impls = traits
-        .iter()
-        .map(|device_trait| {
-            quote! {
-                // Default impl
-                impl<T> #name<dyn #device_trait> for T
-                where
-                    T: #interface_ident + 'static,
-                {
-                    default fn is(&self) -> bool {
-                        false
-                    }
-
-                    default fn cast(&self) -> Option<&(dyn #device_trait + 'static)> {
-                        None
-                    }
-
-                    default fn cast_mut(&mut self) -> Option<&mut (dyn #device_trait + 'static)> {
-                        None
-                    }
-                }
-
-                // Specialization, should not cause any unsoundness as we dispatch based on
-                // #device_trait
-                impl<T> #name<dyn #device_trait> for T
-                where
-                    T: #interface_ident + #device_trait + 'static,
-                {
-                    fn is(&self) -> bool {
-                        true
-                    }
-
-                    fn cast(&self) -> Option<&(dyn #device_trait + 'static)> {
-                        Some(self)
-                    }
-
-                    fn cast_mut(&mut self) -> Option<&mut (dyn #device_trait + 'static)> {
-                        Some(self)
-                    }
-                }
-            }
-        })
-        .fold(quote! {}, |acc, x| {
-            quote! {
-                // Not sure if this is the right way to do this
-                #acc
-                #x
-            }
-        });
-
-    let tokens = quote! {
-        #interface
-        #prefix
-        #impls
-    };
-
-    tokens.into()
-}
-
-// TODO: Not sure if this makes sense to have?
-/// This macro ensures that the device traits have the correct trait bounds
-#[proc_macro_attribute]
-pub fn device_trait(_attr: TokenStream, item: TokenStream) -> TokenStream {
-    let mut interface: ItemTrait = parse_macro_input!(item);
-
-    interface.supertraits.push(TypeParamBound::Verbatim(quote! {
-        ::core::marker::Sync + ::core::marker::Send
-    }));
-
-    #[cfg(feature = "debug")]
-    interface.supertraits.push(TypeParamBound::Verbatim(quote! {
-        ::std::fmt::Debug
-    }));
-
-    interface.into_token_stream().into()
-}

src/device_manager.rs

@@ -12,7 +12,7 @@ use tokio_cron_scheduler::{Job, JobScheduler};
 use tracing::{debug, error, instrument, trace};
 
 use crate::devices::{
-    AirFilterConfig, As, AudioSetupConfig, ContactSensorConfig, DebugBridgeConfig, Device,
+    AirFilterConfig, AudioSetupConfig, ContactSensorConfig, DebugBridgeConfig, Device,
     HueBridgeConfig, HueGroupConfig, IkeaOutletConfig, KasaOutletConfig, LightSensorConfig,
     WakeOnLANConfig, WasherConfig,
 };
@@ -106,22 +106,22 @@ impl DeviceManager {
                                     let device = manager.get(&target).await.unwrap();
                                     match action {
                                         Action::On => {
-                                            As::<dyn OnOff>::cast_mut(
-                                                device.write().await.as_mut(),
-                                            )
-                                            .unwrap()
-                                            .set_on(true)
-                                            .await
-                                            .unwrap();
+                                            let mut device = device.write().await;
+                                            let device: Option<&mut dyn OnOff> =
+                                                device.as_mut().cast_mut();
+
+                                            if let Some(device) = device {
+                                                device.set_on(true).await.unwrap();
+                                            }
                                         }
                                         Action::Off => {
-                                            As::<dyn OnOff>::cast_mut(
-                                                device.write().await.as_mut(),
-                                            )
-                                            .unwrap()
-                                            .set_on(false)
-                                            .await
-                                            .unwrap();
+                                            let mut device = device.write().await;
+                                            let device: Option<&mut dyn OnOff> =
+                                                device.as_mut().cast_mut();
+
+                                            if let Some(device) = device {
+                                                device.set_on(false).await.unwrap();
+                                            }
                                         }
                                     }
                                 }
@@ -142,14 +142,17 @@ impl DeviceManager {
 
         debug!(id, "Adding device");
 
-        // If the device listens to mqtt, subscribe to the topics
-        if let Some(device) = As::<dyn OnMqtt>::cast(device.as_ref()) {
-            for topic in device.topics() {
-                trace!(id, topic, "Subscribing to topic");
-                if let Err(err) = self.client.subscribe(topic, QoS::AtLeastOnce).await {
-                    // NOTE: Pretty sure that this can only happen if the mqtt client if no longer
-                    // running
-                    error!(id, topic, "Failed to subscribe to topic: {err}");
+        {
+            // If the device listens to mqtt, subscribe to the topics
+            let device: Option<&dyn OnMqtt> = device.as_ref().cast();
+            if let Some(device) = device {
+                for topic in device.topics() {
+                    trace!(id, topic, "Subscribing to topic");
+                    if let Err(err) = self.client.subscribe(topic, QoS::AtLeastOnce).await {
+                        // NOTE: Pretty sure that this can only happen if the mqtt client if no longer
+                        // running
+                        error!(id, topic, "Failed to subscribe to topic: {err}");
+                    }
                 }
             }
         }
@@ -199,8 +202,8 @@ impl DeviceManager {
                     let message = message.clone();
                     async move {
                         let mut device = device.write().await;
-                        let device = device.as_mut();
-                        if let Some(device) = As::<dyn OnMqtt>::cast_mut(device) {
+                        let device: Option<&mut dyn OnMqtt> = device.as_mut().cast_mut();
+                        if let Some(device) = device {
                             let subscribed = device
                                 .topics()
                                 .iter()
@@ -220,8 +223,8 @@ impl DeviceManager {
                 let devices = self.devices.read().await;
                 let iter = devices.iter().map(|(id, device)| async move {
                     let mut device = device.write().await;
-                    let device = device.as_mut();
-                    if let Some(device) = As::<dyn OnDarkness>::cast_mut(device) {
+                    let device: Option<&mut dyn OnDarkness> = device.as_mut().cast_mut();
+                    if let Some(device) = device {
                         trace!(id, "Handling");
                         device.on_darkness(dark).await;
                     }
@@ -233,8 +236,8 @@ impl DeviceManager {
                 let devices = self.devices.read().await;
                 let iter = devices.iter().map(|(id, device)| async move {
                     let mut device = device.write().await;
-                    let device = device.as_mut();
-                    if let Some(device) = As::<dyn OnPresence>::cast_mut(device) {
+                    let device: Option<&mut dyn OnPresence> = device.as_mut().cast_mut();
+                    if let Some(device) = device {
                         trace!(id, "Handling");
                         device.on_presence(presence).await;
                     }
@@ -248,8 +251,8 @@ impl DeviceManager {
                     let notification = notification.clone();
                     async move {
                         let mut device = device.write().await;
-                        let device = device.as_mut();
-                        if let Some(device) = As::<dyn OnNotification>::cast_mut(device) {
+                        let device: Option<&mut dyn OnNotification> = device.as_mut().cast_mut();
+                        if let Some(device) = device {
                             trace!(id, "Handling");
                             device.on_notification(notification).await;
                         }

src/devices/audio_setup.rs

@@ -6,7 +6,6 @@ use tracing::{debug, error, trace, warn};
 use super::Device;
 use crate::config::MqttDeviceConfig;
 use crate::device_manager::{ConfigExternal, DeviceConfig, WrappedDevice};
-use crate::devices::As;
 use crate::error::DeviceConfigError;
 use crate::event::{OnMqtt, OnPresence};
 use crate::messages::{RemoteAction, RemoteMessage};
@@ -39,8 +38,11 @@ impl DeviceConfig for AudioSetupConfig {
                 self.mixer.clone(),
             ))?;
 
-        if !As::<dyn OnOff>::is(mixer.read().await.as_ref()) {
-            return Err(DeviceConfigError::MissingTrait(self.mixer, "OnOff".into()));
+        {
+            let mixer = mixer.read().await;
+            if (mixer.as_ref().cast() as Option<&dyn OnOff>).is_none() {
+                return Err(DeviceConfigError::MissingTrait(self.mixer, "OnOff".into()));
+            }
         }
 
         let speakers =
@@ -52,11 +54,11 @@ impl DeviceConfig for AudioSetupConfig {
                     self.speakers.clone(),
                 ))?;
 
-        if !As::<dyn OnOff>::is(speakers.read().await.as_ref()) {
-            return Err(DeviceConfigError::MissingTrait(
-                self.speakers,
-                "OnOff".into(),
-            ));
+        {
+            let speakers = speakers.read().await;
+            if (speakers.as_ref().cast() as Option<&dyn OnOff>).is_none() {
+                return Err(DeviceConfigError::MissingTrait(self.mixer, "OnOff".into()));
+            }
         }
 
         let device = AudioSetup {
@@ -103,8 +105,8 @@ impl OnMqtt for AudioSetup {
         let mut mixer = self.mixer.write().await;
         let mut speakers = self.speakers.write().await;
         if let (Some(mixer), Some(speakers)) = (
-            As::<dyn OnOff>::cast_mut(mixer.as_mut()),
-            As::<dyn OnOff>::cast_mut(speakers.as_mut()),
+            mixer.as_mut().cast_mut() as Option<&mut dyn OnOff>,
+            speakers.as_mut().cast_mut() as Option<&mut dyn OnOff>,
         ) {
             match action {
 				RemoteAction::On => {
@@ -137,10 +139,9 @@ impl OnPresence for AudioSetup {
     async fn on_presence(&mut self, presence: bool) {
         let mut mixer = self.mixer.write().await;
         let mut speakers = self.speakers.write().await;
-
         if let (Some(mixer), Some(speakers)) = (
-            As::<dyn OnOff>::cast_mut(mixer.as_mut()),
-            As::<dyn OnOff>::cast_mut(speakers.as_mut()),
+            mixer.as_mut().cast_mut() as Option<&mut dyn OnOff>,
+            speakers.as_mut().cast_mut() as Option<&mut dyn OnOff>,
         ) {
             // Turn off the audio setup when we leave the house
             if !presence {

src/devices/contact_sensor.rs

@@ -11,7 +11,7 @@ use tracing::{debug, error, trace, warn};
 use super::Device;
 use crate::config::MqttDeviceConfig;
 use crate::device_manager::{ConfigExternal, DeviceConfig, WrappedDevice};
-use crate::devices::{As, DEFAULT_PRESENCE};
+use crate::devices::DEFAULT_PRESENCE;
 use crate::error::DeviceConfigError;
 use crate::event::{OnMqtt, OnPresence};
 use crate::messages::{ContactMessage, PresenceMessage};
@@ -60,20 +60,23 @@ impl DeviceConfig for ContactSensorConfig {
                     DeviceConfigError::MissingChild(device_name.into(), "OnOff".into()),
                 )?;
 
-                if !As::<dyn OnOff>::is(device.read().await.as_ref()) {
-                    return Err(DeviceConfigError::MissingTrait(
-                        device_name.into(),
-                        "OnOff".into(),
-                    ));
-                }
-
-                if !trigger_config.timeout.is_zero()
-                    && !As::<dyn Timeout>::is(device.read().await.as_ref())
                 {
-                    return Err(DeviceConfigError::MissingTrait(
-                        device_name.into(),
-                        "Timeout".into(),
-                    ));
+                    let device = device.read().await;
+                    if (device.as_ref().cast() as Option<&dyn OnOff>).is_none() {
+                        return Err(DeviceConfigError::MissingTrait(
+                            device_name.into(),
+                            "OnOff".into(),
+                        ));
+                    }
+
+                    if trigger_config.timeout.is_zero()
+                        && (device.as_ref().cast() as Option<&dyn Timeout>).is_none()
+                    {
+                        return Err(DeviceConfigError::MissingTrait(
+                            device_name.into(),
+                            "Timeout".into(),
+                        ));
+                    }
                 }
 
                 devices.push((device, false));
@@ -161,7 +164,7 @@ impl OnMqtt for ContactSensor {
             if !self.is_closed {
                 for (light, previous) in &mut trigger.devices {
                     let mut light = light.write().await;
-                    if let Some(light) = As::<dyn OnOff>::cast_mut(light.as_mut()) {
+                    if let Some(light) = light.as_mut().cast_mut() as Option<&mut dyn OnOff> {
                         *previous = light.is_on().await.unwrap();
                         light.set_on(true).await.ok();
                     }
@@ -172,10 +175,12 @@ impl OnMqtt for ContactSensor {
                     if !previous {
                         // If the timeout is zero just turn the light off directly
                         if trigger.timeout.is_zero()
-                            && let Some(light) = As::<dyn OnOff>::cast_mut(light.as_mut())
+                            && let Some(light) = light.as_mut().cast_mut() as Option<&mut dyn OnOff>
                         {
                             light.set_on(false).await.ok();
-                        } else if let Some(light) = As::<dyn Timeout>::cast_mut(light.as_mut()) {
+                        } else if let Some(light) =
+                            light.as_mut().cast_mut() as Option<&mut dyn Timeout>
+                        {
                             light.start_timeout(trigger.timeout).await.unwrap();
                         }
                         // TODO: Put a warning/error on creation if either of this has to option to fail

src/devices/mod.rs

@@ -12,8 +12,11 @@ mod presence;
 mod wake_on_lan;
 mod washer;
 
-use google_home::device::AsGoogleHomeDevice;
+use std::fmt::Debug;
+
+use automation_cast::Cast;
 use google_home::traits::OnOff;
+use google_home::GoogleHomeDevice;
 
 pub use self::air_filter::AirFilterConfig;
 pub use self::audio_setup::AudioSetupConfig;
@@ -31,7 +34,18 @@ pub use self::washer::WasherConfig;
 use crate::event::{OnDarkness, OnMqtt, OnNotification, OnPresence};
 use crate::traits::Timeout;
 
-#[impl_cast::device(As: OnMqtt + OnPresence + OnDarkness + OnNotification + OnOff + Timeout)]
-pub trait Device: AsGoogleHomeDevice + std::fmt::Debug + Sync + Send {
+pub trait Device:
+    Debug
+    + Sync
+    + Send
+    + Cast<dyn GoogleHomeDevice>
+    + Cast<dyn OnMqtt>
+    + Cast<dyn OnMqtt>
+    + Cast<dyn OnPresence>
+    + Cast<dyn OnDarkness>
+    + Cast<dyn OnNotification>
+    + Cast<dyn OnOff>
+    + Cast<dyn Timeout>
+{
     fn get_id(&self) -> &str;
 }

src/event.rs

@@ -1,5 +1,4 @@
 use async_trait::async_trait;
-use impl_cast::device_trait;
 use rumqttc::Publish;
 use tokio::sync::mpsc;
 
@@ -32,26 +31,22 @@ impl EventChannel {
 }
 
 #[async_trait]
-#[device_trait]
-pub trait OnMqtt {
+pub trait OnMqtt: Sync + Send {
     fn topics(&self) -> Vec<&str>;
     async fn on_mqtt(&mut self, message: Publish);
 }
 
 #[async_trait]
-#[device_trait]
-pub trait OnPresence {
+pub trait OnPresence: Sync + Send {
     async fn on_presence(&mut self, presence: bool);
 }
 
 #[async_trait]
-#[device_trait]
-pub trait OnDarkness {
+pub trait OnDarkness: Sync + Send {
     async fn on_darkness(&mut self, dark: bool);
 }
 
 #[async_trait]
-#[device_trait]
-pub trait OnNotification {
+pub trait OnNotification: Sync + Send {
     async fn on_notification(&mut self, notification: Notification);
 }

src/traits.rs

@@ -2,11 +2,9 @@ use std::time::Duration;
 
 use anyhow::Result;
 use async_trait::async_trait;
-use impl_cast::device_trait;
 
 #[async_trait]
-#[device_trait]
-pub trait Timeout {
+pub trait Timeout: Sync + Send {
     async fn start_timeout(&mut self, _timeout: Duration) -> Result<()>;
     async fn stop_timeout(&mut self) -> Result<()>;
 }