embassy, embassy-nrf: add `nightly` Cargo feature to gate nightly-only features.

19 files changed, 182 insertions, 126 deletions

diff --git a/.vscode/settings.json b/.vscode/settings.json
index 3defc907..79433a7c 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -4,16 +4,19 @@
   "rust-analyzer.assist.importGranularity": "module",
   "rust-analyzer.checkOnSave.allFeatures": false,
   "rust-analyzer.checkOnSave.allTargets": false,
-  "rust-analyzer.checkOnSave.command": "clippy",
+  "rust-analyzer.checkOnSave.noDefaultFeatures": true,
+  "rust-analyzer.cargo.allFeatures": false,
   "rust-analyzer.cargo.noDefaultFeatures": true,
   "rust-analyzer.experimental.procAttrMacros": false,
-  "rust-analyzer.checkOnSave.noDefaultFeatures": true,
+  "rust-analyzer.procMacro.enable": true,
+  "rust-analyzer.cargo.runBuildScripts": true,
   "rust-analyzer.cargo.target": "thumbv7em-none-eabi",
   "rust-analyzer.cargo.features": [
     // These are needed to prevent embassy-net from failing to build
     //"embassy-net/medium-ethernet",
     //"embassy-net/tcp",
     //"embassy-net/pool-16",
+    "nightly",
   ],
   "rust-analyzer.linkedProjects": [
     // Declare for the target you wish to develop
@@ -35,12 +38,4 @@
     // "examples/stm32wl55/Cargo.toml",
     // "examples/wasm/Cargo.toml",
   ],
-  "rust-analyzer.procMacro.enable": true,
-  "rust-analyzer.cargo.runBuildScripts": true,
-  "files.watcherExclude": {
-    "**/.git/objects/**": true,
-    "**/.git/subtree-cache/**": true,
-    "**/target/**": true
-  },
-  "git.ignoreLimitWarning": true
 }
\ No newline at end of file
diff --git a/ci.sh b/ci.sh
index 452130be..cd0db286 100755
--- a/ci.sh
+++ b/ci.sh
@@ -24,24 +24,24 @@ rm -rf stm32-metapac
 mv stm32-metapac-gen/out stm32-metapac
 
 cargo batch  \
-    --- build --release --manifest-path embassy/Cargo.toml --target thumbv7em-none-eabi \
-    --- build --release --manifest-path embassy/Cargo.toml --target thumbv7em-none-eabi --features log,executor-agnostic \
-    --- build --release --manifest-path embassy/Cargo.toml --target thumbv7em-none-eabi --features defmt \
-    --- build --release --manifest-path embassy/Cargo.toml --target thumbv6m-none-eabi --features defmt \
-    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nrf52805,gpiote,time-driver-rtc1 \
-    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nrf52810,gpiote,time-driver-rtc1 \
-    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nrf52811,gpiote,time-driver-rtc1 \
-    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nrf52820,gpiote,time-driver-rtc1 \
-    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nrf52832,gpiote,time-driver-rtc1 \
-    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nrf52833,gpiote,time-driver-rtc1,unstable-traits \
-    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv8m.main-none-eabihf --features nrf9160-s,gpiote,time-driver-rtc1 \
-    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv8m.main-none-eabihf --features nrf9160-ns,gpiote,time-driver-rtc1,unstable-traits \
-    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv8m.main-none-eabihf --features nrf5340-app-s,gpiote,time-driver-rtc1,unstable-traits \
-    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv8m.main-none-eabihf --features nrf5340-app-ns,gpiote,time-driver-rtc1 \
-    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv8m.main-none-eabihf --features nrf5340-net,gpiote,time-driver-rtc1,unstable-traits \
-    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nrf52840,gpiote,time-driver-rtc1 \
-    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nrf52840,log,gpiote,time-driver-rtc1 \
-    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nrf52840,defmt,gpiote,time-driver-rtc1,unstable-traits \
+    --- build --release --manifest-path embassy/Cargo.toml --target thumbv7em-none-eabi --features nightly \
+    --- build --release --manifest-path embassy/Cargo.toml --target thumbv7em-none-eabi --features nightly,log,executor-agnostic \
+    --- build --release --manifest-path embassy/Cargo.toml --target thumbv7em-none-eabi --features nightly,defmt \
+    --- build --release --manifest-path embassy/Cargo.toml --target thumbv6m-none-eabi --features nightly,defmt \
+    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nightly,nrf52805,gpiote,time-driver-rtc1 \
+    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nightly,nrf52810,gpiote,time-driver-rtc1 \
+    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nightly,nrf52811,gpiote,time-driver-rtc1 \
+    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nightly,nrf52820,gpiote,time-driver-rtc1 \
+    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nightly,nrf52832,gpiote,time-driver-rtc1 \
+    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nightly,nrf52833,gpiote,time-driver-rtc1,unstable-traits \
+    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv8m.main-none-eabihf --features nightly,nrf9160-s,gpiote,time-driver-rtc1 \
+    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv8m.main-none-eabihf --features nightly,nrf9160-ns,gpiote,time-driver-rtc1,unstable-traits \
+    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv8m.main-none-eabihf --features nightly,nrf5340-app-s,gpiote,time-driver-rtc1,unstable-traits \
+    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv8m.main-none-eabihf --features nightly,nrf5340-app-ns,gpiote,time-driver-rtc1 \
+    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv8m.main-none-eabihf --features nightly,nrf5340-net,gpiote,time-driver-rtc1,unstable-traits \
+    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nightly,nrf52840,gpiote,time-driver-rtc1 \
+    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nightly,nrf52840,log,gpiote,time-driver-rtc1 \
+    --- build --release --manifest-path embassy-nrf/Cargo.toml --target thumbv7em-none-eabi --features nightly,nrf52840,defmt,gpiote,time-driver-rtc1,unstable-traits \
     --- build --release --manifest-path embassy-stm32/Cargo.toml --target thumbv7em-none-eabi --features stm32f411ce,defmt,time-driver-any \
     --- build --release --manifest-path embassy-stm32/Cargo.toml --target thumbv7em-none-eabi --features stm32f411ce,defmt,time-driver-any,unstable-traits \
     --- build --release --manifest-path embassy-stm32/Cargo.toml --target thumbv7em-none-eabi --features stm32f429zi,log,time-driver-any \
diff --git a/docs/modules/ROOT/examples/basic/Cargo.toml b/docs/modules/ROOT/examples/basic/Cargo.toml
index 0f1c30da..ed1c3cb1 100644
--- a/docs/modules/ROOT/examples/basic/Cargo.toml
+++ b/docs/modules/ROOT/examples/basic/Cargo.toml
@@ -5,8 +5,8 @@ name = "embassy-basic-example"
 version = "0.1.0"
 
 [dependencies]
-embassy = { version = "0.1.0", path = "../../../../../embassy", features = ["defmt"] }
-embassy-nrf = { version = "0.1.0", path = "../../../../../embassy-nrf", features = ["defmt", "nrf52840", "time-driver-rtc1", "gpiote"] }
+embassy = { version = "0.1.0", path = "../../../../../embassy", features = ["defmt", "nightly"] }
+embassy-nrf = { version = "0.1.0", path = "../../../../../embassy-nrf", features = ["defmt", "nrf52840", "time-driver-rtc1", "gpiote", "nightly"] }
 
 defmt = "0.3"
 defmt-rtt = "0.3"
diff --git a/embassy-nrf/Cargo.toml b/embassy-nrf/Cargo.toml
index 4ed922ba..5ced9b1b 100644
--- a/embassy-nrf/Cargo.toml
+++ b/embassy-nrf/Cargo.toml
@@ -6,14 +6,18 @@ edition = "2018"
 
 [features]
 
+# Enable nightly-only features
+nightly = ["embassy/nightly", "embedded-hal-1", "embedded-hal-async"]
+
 # Reexport the PAC for the currently enabled chip at `embassy_nrf::pac`.
 # This is unstable because semver-minor (non-breaking) releases of embassy-nrf may major-bump (breaking) the PAC version.
 # If this is an issue for you, you're encouraged to directly depend on a fixed version of the PAC.
 # There are no plans to make this stable.
 unstable-pac = []
 
-# Implement embedded-hal 1.0 alpha and embedded-hal-async traits.
-unstable-traits = ["embedded-hal-1", "embedded-hal-async"]
+# Implement embedded-hal 1.0 alpha traits.
+# Implement embedded-hal-async traits if `nightly` is set as well.
+unstable-traits = ["embedded-hal-1"]
 
 nrf52805 = ["nrf52805-pac", "_ppi"]
 nrf52810 = ["nrf52810-pac", "_ppi"]
diff --git a/embassy-nrf/src/gpiote.rs b/embassy-nrf/src/gpiote.rs
index a4c24058..b856c2df 100644
--- a/embassy-nrf/src/gpiote.rs
+++ b/embassy-nrf/src/gpiote.rs
@@ -463,7 +463,6 @@ mod eh02 {
 #[cfg(feature = "unstable-traits")]
 mod eh1 {
     use super::*;
-    use futures::FutureExt;
 
     impl<'d, C: Channel, T: GpioPin> embedded_hal_1::digital::ErrorType for InputChannel<'d, C, T> {
         type Error = Infallible;
@@ -480,6 +479,12 @@ mod eh1 {
             self.pin.is_low()
         }
     }
+}
+
+#[cfg(all(feature = "unstable-traits", feature = "nightly"))]
+mod eh1a {
+    use super::*;
+    use futures::FutureExt;
 
     impl<'d, T: GpioPin> embedded_hal_async::digital::Wait for Input<'d, T> {
         type WaitForHighFuture<'a>
diff --git a/embassy-nrf/src/lib.rs b/embassy-nrf/src/lib.rs
index 8e05d9b6..b448f6ab 100644
--- a/embassy-nrf/src/lib.rs
+++ b/embassy-nrf/src/lib.rs
@@ -1,6 +1,8 @@
 #![no_std]
-#![feature(generic_associated_types)]
-#![feature(type_alias_impl_trait)]
+#![cfg_attr(
+    feature = "nightly",
+    feature(generic_associated_types, type_alias_impl_trait)
+)]
 
 #[cfg(not(any(
     feature = "nrf51",
diff --git a/embassy-nrf/src/spim.rs b/embassy-nrf/src/spim.rs
index cd43b26e..aac20e17 100644
--- a/embassy-nrf/src/spim.rs
+++ b/embassy-nrf/src/spim.rs
@@ -333,7 +333,6 @@ mod eh02 {
 #[cfg(feature = "unstable-traits")]
 mod eh1 {
     use super::*;
-    use core::future::Future;
 
     impl embedded_hal_1::spi::Error for Error {
         fn kind(&self) -> embedded_hal_1::spi::ErrorKind {
@@ -396,7 +395,7 @@ mod eh1 {
 
         fn transaction<'a>(
             &mut self,
-            operations: &mut [embedded_hal_async::spi::Operation<'a, u8>],
+            operations: &mut [embedded_hal_1::spi::blocking::Operation<'a, u8>],
         ) -> Result<(), Self::Error> {
             use embedded_hal_1::spi::blocking::Operation;
             for o in operations {
@@ -410,6 +409,12 @@ mod eh1 {
             Ok(())
         }
     }
+}
+
+#[cfg(all(feature = "unstable-traits", feature = "nightly"))]
+mod eh1a {
+    use super::*;
+    use core::future::Future;
 
     impl<'d, T: Instance> embedded_hal_async::spi::Read<u8> for Spim<'d, T> {
         type ReadFuture<'a>
diff --git a/embassy-nrf/src/twim.rs b/embassy-nrf/src/twim.rs
index 4cd47c89..ed2844f7 100644
--- a/embassy-nrf/src/twim.rs
+++ b/embassy-nrf/src/twim.rs
@@ -679,7 +679,7 @@ mod eh1 {
         fn transaction<'a>(
             &mut self,
             _address: u8,
-            _operations: &mut [embedded_hal_async::i2c::Operation<'a>],
+            _operations: &mut [embedded_hal_1::i2c::blocking::Operation<'a>],
         ) -> Result<(), Self::Error> {
             todo!();
         }
@@ -690,58 +690,59 @@ mod eh1 {
             _operations: O,
         ) -> Result<(), Self::Error>
         where
-            O: IntoIterator<Item = embedded_hal_async::i2c::Operation<'a>>,
+            O: IntoIterator<Item = embedded_hal_1::i2c::blocking::Operation<'a>>,
         {
             todo!();
         }
     }
+}
 
-    impl<'d, T: Instance> embedded_hal_async::i2c::I2c for Twim<'d, T> {
-        type ReadFuture<'a>
-        where
-            Self: 'a,
-        = impl Future<Output = Result<(), Self::Error>> + 'a;
+#[cfg(all(feature = "unstable-traits", feature = "nightly"))]
+impl<'d, T: Instance> embedded_hal_async::i2c::I2c for Twim<'d, T> {
+    type ReadFuture<'a>
+    where
+        Self: 'a,
+    = impl Future<Output = Result<(), Self::Error>> + 'a;
 
-        fn read<'a>(&'a mut self, address: u8, buffer: &'a mut [u8]) -> Self::ReadFuture<'a> {
-            self.read(address, buffer)
-        }
+    fn read<'a>(&'a mut self, address: u8, buffer: &'a mut [u8]) -> Self::ReadFuture<'a> {
+        self.read(address, buffer)
+    }
 
-        type WriteFuture<'a>
-        where
-            Self: 'a,
-        = impl Future<Output = Result<(), Self::Error>> + 'a;
+    type WriteFuture<'a>
+    where
+        Self: 'a,
+    = impl Future<Output = Result<(), Self::Error>> + 'a;
 
-        fn write<'a>(&'a mut self, address: u8, bytes: &'a [u8]) -> Self::WriteFuture<'a> {
-            self.write(address, bytes)
-        }
+    fn write<'a>(&'a mut self, address: u8, bytes: &'a [u8]) -> Self::WriteFuture<'a> {
+        self.write(address, bytes)
+    }
 
-        type WriteReadFuture<'a>
-        where
-            Self: 'a,
-        = impl Future<Output = Result<(), Self::Error>> + 'a;
+    type WriteReadFuture<'a>
+    where
+        Self: 'a,
+    = impl Future<Output = Result<(), Self::Error>> + 'a;
 
-        fn write_read<'a>(
-            &'a mut self,
-            address: u8,
-            wr_buffer: &'a [u8],
-            rd_buffer: &'a mut [u8],
-        ) -> Self::WriteReadFuture<'a> {
-            self.write_read(address, wr_buffer, rd_buffer)
-        }
+    fn write_read<'a>(
+        &'a mut self,
+        address: u8,
+        wr_buffer: &'a [u8],
+        rd_buffer: &'a mut [u8],
+    ) -> Self::WriteReadFuture<'a> {
+        self.write_read(address, wr_buffer, rd_buffer)
+    }
 
-        type TransactionFuture<'a>
-        where
-            Self: 'a,
-        = impl Future<Output = Result<(), Self::Error>> + 'a;
+    type TransactionFuture<'a>
+    where
+        Self: 'a,
+    = impl Future<Output = Result<(), Self::Error>> + 'a;
 
-        fn transaction<'a>(
-            &'a mut self,
-            address: u8,
-            operations: &mut [embedded_hal_async::i2c::Operation<'a>],
-        ) -> Self::TransactionFuture<'a> {
-            let _ = address;
-            let _ = operations;
-            async move { todo!() }
-        }
+    fn transaction<'a>(
+        &'a mut self,
+        address: u8,
+        operations: &mut [embedded_hal_async::i2c::Operation<'a>],
+    ) -> Self::TransactionFuture<'a> {
+        let _ = address;
+        let _ = operations;
+        async move { todo!() }
     }
 }
diff --git a/embassy-nrf/src/uarte.rs b/embassy-nrf/src/uarte.rs
index b10e55a0..c7177dc2 100644
--- a/embassy-nrf/src/uarte.rs
+++ b/embassy-nrf/src/uarte.rs
@@ -760,7 +760,6 @@ mod eh02 {
 #[cfg(feature = "unstable-traits")]
 mod eh1 {
     use super::*;
-    use core::future::Future;
 
     impl embedded_hal_1::serial::Error for Error {
         fn kind(&self) -> embedded_hal_1::serial::ErrorKind {
@@ -788,6 +787,36 @@ mod eh1 {
         }
     }
 
+    impl<'d, T: Instance> embedded_hal_1::serial::ErrorType for UarteTx<'d, T> {
+        type Error = Error;
+    }
+
+    impl<'d, T: Instance> embedded_hal_1::serial::blocking::Write for UarteTx<'d, T> {
+        fn write(&mut self, buffer: &[u8]) -> Result<(), Self::Error> {
+            self.blocking_write(buffer)
+        }
+
+        fn flush(&mut self) -> Result<(), Self::Error> {
+            Ok(())
+        }
+    }
+
+    impl<'d, T: Instance> embedded_hal_1::serial::ErrorType for UarteRx<'d, T> {
+        type Error = Error;
+    }
+
+    impl<'d, U: Instance, T: TimerInstance> embedded_hal_1::serial::ErrorType
+        for UarteWithIdle<'d, U, T>
+    {
+        type Error = Error;
+    }
+}
+
+#[cfg(all(feature = "unstable-traits", feature = "nightly"))]
+mod eh1a {
+    use super::*;
+    use core::future::Future;
+
     impl<'d, T: Instance> embedded_hal_async::serial::Read for Uarte<'d, T> {
         type ReadFuture<'a>
         where
@@ -819,22 +848,6 @@ mod eh1 {
         }
     }
 
-    // =====================
-
-    impl<'d, T: Instance> embedded_hal_1::serial::ErrorType for UarteTx<'d, T> {
-        type Error = Error;
-    }
-
-    impl<'d, T: Instance> embedded_hal_1::serial::blocking::Write for UarteTx<'d, T> {
-        fn write(&mut self, buffer: &[u8]) -> Result<(), Self::Error> {
-            self.blocking_write(buffer)
-        }
-
-        fn flush(&mut self) -> Result<(), Self::Error> {
-            Ok(())
-        }
-    }
-
     impl<'d, T: Instance> embedded_hal_async::serial::Write for UarteTx<'d, T> {
         type WriteFuture<'a>
         where
@@ -855,12 +868,6 @@ mod eh1 {
         }
     }
 
-    // =====================
-
-    impl<'d, T: Instance> embedded_hal_1::serial::ErrorType for UarteRx<'d, T> {
-        type Error = Error;
-    }
-
     impl<'d, T: Instance> embedded_hal_async::serial::Read for UarteRx<'d, T> {
         type ReadFuture<'a>
         where
@@ -872,14 +879,6 @@ mod eh1 {
         }
     }
 
-    // =====================
-
-    impl<'d, U: Instance, T: TimerInstance> embedded_hal_1::serial::ErrorType
-        for UarteWithIdle<'d, U, T>
-    {
-        type Error = Error;
-    }
-
     impl<'d, U: Instance, T: TimerInstance> embedded_hal_async::serial::Read
         for UarteWithIdle<'d, U, T>
     {
diff --git a/embassy-rp/Cargo.toml b/embassy-rp/Cargo.toml
index be41f95e..cb654402 100644
--- a/embassy-rp/Cargo.toml
+++ b/embassy-rp/Cargo.toml
@@ -13,7 +13,7 @@ edition = "2018"
 unstable-pac = []
 
 [dependencies]
-embassy = { version = "0.1.0", path = "../embassy", features = [ "time-tick-1mhz" ] }
+embassy = { version = "0.1.0", path = "../embassy", features = [ "time-tick-1mhz", "nightly"] }
 embassy-hal-common = {version = "0.1.0", path = "../embassy-hal-common" }
 embassy-macros = { version = "0.1.0", path = "../embassy-macros", features = ["rp"]}
 atomic-polyfill = "0.1.5"
diff --git a/embassy-stm32/Cargo.toml b/embassy-stm32/Cargo.toml
index 386722d4..55a646d4 100644
--- a/embassy-stm32/Cargo.toml
+++ b/embassy-stm32/Cargo.toml
@@ -6,7 +6,7 @@ edition = "2018"
 resolver = "2"
 
 [dependencies]
-embassy = { version = "0.1.0", path = "../embassy" }
+embassy = { version = "0.1.0", path = "../embassy", features = ["nightly"]}
 embassy-macros = { version = "0.1.0", path = "../embassy-macros", features = ["stm32"] }
 embassy-hal-common = {version = "0.1.0", path = "../embassy-hal-common" }
 embassy-net = { version = "0.1.0", path = "../embassy-net", default-features = false, optional = true }
diff --git a/embassy/Cargo.toml b/embassy/Cargo.toml
index ccb5574d..d10a8874 100644
--- a/embassy/Cargo.toml
+++ b/embassy/Cargo.toml
@@ -10,8 +10,12 @@ default = []
 std = ["futures/std", "time", "time-tick-1mhz", "embassy-macros/std"]
 wasm = ["wasm-bindgen", "js-sys", "embassy-macros/wasm", "wasm-timer", "time", "time-tick-1mhz"]
 
+# Enable nightly-only features
+nightly = ["embedded-hal-async"]
+
 # Implement embedded-hal 1.0 alpha and embedded-hal-async traits.
-unstable-traits = ["embedded-hal-1", "embedded-hal-async"]
+# Implement embedded-hal-async traits if `nightly` is set as well.
+unstable-traits = ["embedded-hal-1"]
 
 # Enable `embassy::time` module. 
 # NOTE: This feature is only intended to be enabled by crates providing the time driver implementation.
diff --git a/embassy/src/channel/signal.rs b/embassy/src/channel/signal.rs
index 87922b2f..027f4f47 100644
--- a/embassy/src/channel/signal.rs
+++ b/embassy/src/channel/signal.rs
@@ -32,13 +32,15 @@ enum State<T> {
 unsafe impl<T: Send> Send for Signal<T> {}
 unsafe impl<T: Send> Sync for Signal<T> {}
 
-impl<T: Send> Signal<T> {
+impl<T> Signal<T> {
     pub const fn new() -> Self {
         Self {
             state: UnsafeCell::new(State::None),
         }
     }
+}
 
+impl<T: Send> Signal<T> {
     /// Mark this Signal as completed.
     pub fn signal(&self, val: T) {
         critical_section::with(|_| unsafe {
diff --git a/embassy/src/executor/raw/mod.rs b/embassy/src/executor/raw/mod.rs
index 5ee38715..3ae52ae3 100644
--- a/embassy/src/executor/raw/mod.rs
+++ b/embassy/src/executor/raw/mod.rs
@@ -57,6 +57,7 @@ pub struct TaskHeader {
 }
 
 impl TaskHeader {
+    #[cfg(feature = "nightly")]
     pub(crate) const fn new() -> Self {
         Self {
             state: AtomicU32::new(0),
@@ -71,6 +72,21 @@ impl TaskHeader {
         }
     }
 
+    #[cfg(not(feature = "nightly"))]
+    pub(crate) fn new() -> Self {
+        Self {
+            state: AtomicU32::new(0),
+            run_queue_item: RunQueueItem::new(),
+            executor: Cell::new(ptr::null()),
+            poll_fn: UninitCell::uninit(),
+
+            #[cfg(feature = "time")]
+            expires_at: Cell::new(Instant::from_ticks(0)),
+            #[cfg(feature = "time")]
+            timer_queue_item: timer_queue::TimerQueueItem::new(),
+        }
+    }
+
     pub(crate) unsafe fn enqueue(&self) {
         critical_section::with(|cs| {
             let state = self.state.load(Ordering::Relaxed);
@@ -113,7 +129,8 @@ pub struct TaskStorage<F: Future + 'static> {
 }
 
 impl<F: Future + 'static> TaskStorage<F> {
-    /// Create a new Task, in not-spawned state.
+    /// Create a new TaskStorage, in not-spawned state.
+    #[cfg(feature = "nightly")]
     pub const fn new() -> Self {
         Self {
             raw: TaskHeader::new(),
@@ -121,6 +138,15 @@ impl<F: Future + 'static> TaskStorage<F> {
         }
     }
 
+    /// Create a new TaskStorage, in not-spawned state.
+    #[cfg(not(feature = "nightly"))]
+    pub fn new() -> Self {
+        Self {
+            raw: TaskHeader::new(),
+            future: UninitCell::uninit(),
+        }
+    }
+
     /// Try to spawn a task in a pool.
     ///
     /// See [`Self::spawn()`] for details.
diff --git a/embassy/src/lib.rs b/embassy/src/lib.rs
index 2be0e005..acc71e10 100644
--- a/embassy/src/lib.rs
+++ b/embassy/src/lib.rs
@@ -1,8 +1,13 @@
 #![cfg_attr(not(any(feature = "std", feature = "wasm")), no_std)]
-#![feature(generic_associated_types)]
-#![feature(const_fn_trait_bound)]
-#![feature(const_fn_fn_ptr_basics)]
-#![feature(type_alias_impl_trait)]
+#![cfg_attr(
+    feature = "nightly",
+    feature(
+        const_fn_trait_bound,
+        const_fn_fn_ptr_basics,
+        generic_associated_types,
+        type_alias_impl_trait
+    )
+)]
 #![allow(clippy::new_without_default)]
 
 // This mod MUST go first, so that the others see its macros.
@@ -20,7 +25,8 @@ pub mod io;
 pub mod time;
 pub mod util;
 
-pub use embassy_macros::*;
+#[cfg(feature = "nightly")]
+pub use embassy_macros::{main, task};
 
 #[doc(hidden)]
 /// Implementation details for embassy macros. DO NOT USE.
diff --git a/embassy/src/time/delay.rs b/embassy/src/time/delay.rs
index ff32941e..27ec61fe 100644
--- a/embassy/src/time/delay.rs
+++ b/embassy/src/time/delay.rs
@@ -16,11 +16,7 @@ pub struct Delay;
 
 #[cfg(feature = "unstable-traits")]
 mod eh1 {
-    use core::future::Future;
-    use futures::FutureExt;
-
     use super::*;
-    use crate::time::Timer;
 
     impl embedded_hal_1::delay::blocking::DelayUs for Delay {
         type Error = core::convert::Infallible;
@@ -33,6 +29,14 @@ mod eh1 {
             Ok(block_for(Duration::from_millis(ms as u64)))
         }
     }
+}
+
+#[cfg(all(feature = "unstable-traits", feature = "nightly"))]
+mod eh1a {
+    use super::*;
+    use crate::time::Timer;
+    use core::future::Future;
+    use futures::FutureExt;
 
     impl embedded_hal_async::delay::DelayUs for Delay {
         type Error = core::convert::Infallible;
diff --git a/examples/nrf/Cargo.toml b/examples/nrf/Cargo.toml
index da16bcba..2d9c9953 100644
--- a/examples/nrf/Cargo.toml
+++ b/examples/nrf/Cargo.toml
@@ -4,6 +4,9 @@ edition = "2018"
 name = "embassy-nrf-examples"
 version = "0.1.0"
 
+[features]
+default = ["nightly"]
+nightly = ["embassy-nrf/nightly"]
 
 [dependencies]
 embassy = { version = "0.1.0", path = "../../embassy", features = ["defmt"] }
diff --git a/examples/std/Cargo.toml b/examples/std/Cargo.toml
index 450911fa..ef60fe99 100644
--- a/examples/std/Cargo.toml
+++ b/examples/std/Cargo.toml
@@ -5,7 +5,7 @@ name = "embassy-std-examples"
 version = "0.1.0"
 
 [dependencies]
-embassy = { version = "0.1.0", path = "../../embassy", features = ["log", "std", "time"] }
+embassy = { version = "0.1.0", path = "../../embassy", features = ["log", "std", "time", "nightly"] }
 embassy-net = { version = "0.1.0", path = "../../embassy-net", features=["std", "log", "medium-ethernet", "tcp", "dhcpv4"] }
 
 async-io = "1.6.0"
diff --git a/examples/wasm/Cargo.toml b/examples/wasm/Cargo.toml
index c6218a80..6750f6a6 100644
--- a/examples/wasm/Cargo.toml
+++ b/examples/wasm/Cargo.toml
@@ -8,7 +8,7 @@ version = "0.1.0"
 crate-type = ["cdylib"]
 
 [dependencies]
-embassy = { version = "0.1.0", path = "../../embassy", features = ["log", "wasm"] }
+embassy = { version = "0.1.0", path = "../../embassy", features = ["log", "wasm", "nightly"] }
 
 wasm-logger = "0.2.0"
 wasm-bindgen = "0.2"