Make futures-util and futures-sink optional

embassy-sync/Cargo.toml

@@ -20,15 +20,18 @@ src_base_git = "https://github.com/embassy-rs/embassy/blob/$COMMIT/embassy-sync/
 target = "thumbv7em-none-eabi"
 
 [features]
+default = ["futures-util", "futures-sink"]
 std = []
 turbowakers = []
+futures-sink = ["dep:futures-sink"]
+futures-util = ["dep:futures-util"]
 
 [dependencies]
 defmt = { version = "0.3", optional = true }
 log = { version = "0.4.14", optional = true }
 
-futures-sink = { version = "0.3", default-features = false, features = [] }
-futures-util = { version = "0.3.17", default-features = false }
+futures-sink = { version = "0.3", default-features = false, features = [], optional = true }
+futures-util = { version = "0.3.17", default-features = false, optional = true }
 critical-section = "1.1"
 heapless = "0.8"
 cfg-if = "1.0.0"

embassy-sync/src/channel.rs

@@ -317,6 +317,7 @@ where
     }
 }
 
+#[cfg(feature = "futures-util")]
 impl<'ch, M, T, const N: usize> futures_util::Stream for Receiver<'ch, M, T, N>
 where
     M: RawMutex,
@@ -782,6 +783,7 @@ where
     }
 }
 
+#[cfg(feature = "futures-util")]
 impl<M, T, const N: usize> futures_util::Stream for Channel<M, T, N>
 where
     M: RawMutex,

embassy-sync/src/pubsub/mod.rs

@@ -304,9 +304,9 @@ struct PubSubState<T: Clone, const CAP: usize, const SUBS: usize, const PUBS: us
     /// Don't worry, we won't run out.
     /// If a million messages were published every second, then the ID's would run out in about 584942 years.
     next_message_id: u64,
-    /// Collection of wakers for Subscribers that are waiting.  
+    /// Collection of wakers for Subscribers that are waiting.
     subscriber_wakers: MultiWakerRegistration<SUBS>,
-    /// Collection of wakers for Publishers that are waiting.  
+    /// Collection of wakers for Publishers that are waiting.
     publisher_wakers: MultiWakerRegistration<PUBS>,
     /// The amount of subscribers that are active
     subscriber_count: usize,
@@ -760,6 +760,7 @@ mod tests {
     }
 
     #[futures_test::test]
+    #[cfg(feature = "futures-sink")]
     async fn publisher_sink() {
         use futures_util::{SinkExt, StreamExt};
 

embassy-sync/src/pubsub/publisher.rs

@@ -76,6 +76,7 @@ impl<'a, PSB: PubSubBehavior<T> + ?Sized, T: Clone> Pub<'a, PSB, T> {
     }
 
     /// Create a [`futures::Sink`] adapter for this publisher.
+    #[cfg(feature = "futures-sink")]
     #[inline]
     pub const fn sink(&self) -> PubSink<'a, '_, PSB, T> {
         PubSink { publ: self, fut: None }
@@ -227,6 +228,7 @@ impl<'a, M: RawMutex, T: Clone, const CAP: usize, const SUBS: usize, const PUBS:
     }
 }
 
+#[cfg(feature = "futures-sink")]
 #[must_use = "Sinks do nothing unless polled"]
 /// [`futures_sink::Sink`] adapter for [`Pub`].
 pub struct PubSink<'a, 'p, PSB, T>
@@ -238,6 +240,7 @@ where
     fut: Option<PublisherWaitFuture<'p, 'a, PSB, T>>,
 }
 
+#[cfg(feature = "futures-sink")]
 impl<'a, 'p, PSB, T> PubSink<'a, 'p, PSB, T>
 where
     PSB: PubSubBehavior<T> + ?Sized,
@@ -258,6 +261,7 @@ where
     }
 }
 
+#[cfg(feature = "futures-sink")]
 impl<'a, 'p, PSB, T> futures_sink::Sink<T> for PubSink<'a, 'p, PSB, T>
 where
     PSB: PubSubBehavior<T> + ?Sized,

embassy-sync/src/pubsub/subscriber.rs

@@ -115,6 +115,7 @@ impl<'a, PSB: PubSubBehavior<T> + ?Sized, T: Clone> Unpin for Sub<'a, PSB, T> {}
 
 /// Warning: The stream implementation ignores lag results and returns all messages.
 /// This might miss some messages without you knowing it.
+#[cfg(feature = "futures-util")]
 impl<'a, PSB: PubSubBehavior<T> + ?Sized, T: Clone> futures_util::Stream for Sub<'a, PSB, T> {
     type Item = T;
 

embassy-time/Cargo.toml

@@ -24,6 +24,8 @@ target = "x86_64-unknown-linux-gnu"
 features = ["defmt", "std"]
 
 [features]
+default = ["futures-util"]
+
 ## Display the time since startup next to defmt log messages.
 ## At most 1 `defmt-timestamp-uptime-*` feature can be used.
 ## `defmt-timestamp-uptime` is provided for backwards compatibility (provides the same format as `uptime-us`).
@@ -36,6 +38,9 @@ defmt-timestamp-uptime-ts = ["defmt"]
 defmt-timestamp-uptime-tms = ["defmt"]
 defmt-timestamp-uptime-tus = ["defmt"]
 
+## Disable `futures-util` support
+futures-util = ["dep:futures-util"]
+
 #! ### Time Drivers
 
 #! Usually, time drivers are defined by a HAL, or a companion crate to the HAL. For `std` and WASM
@@ -53,10 +58,10 @@ wasm = ["dep:wasm-bindgen", "dep:js-sys", "dep:wasm-timer", "tick-hz-1_000_000",
 
 #! By default embassy-time uses a timer queue implementation that is faster but depends on `embassy-executor`.
 #! It will panic if you try to await any timer when using another executor.
-#! 
+#!
 #! Alternatively, you can choose to use a "generic" timer queue implementation that works on any executor.
 #! To enable it, enable any of the features below.
-#! 
+#!
 #! The features also set how many timers are used for the generic queue. At most one
 #! `generic-queue-*` feature can be enabled. If none is enabled, `queue_integrated` is used.
 #!
@@ -427,7 +432,7 @@ embedded-hal-02 = { package = "embedded-hal", version = "0.2.6" }
 embedded-hal-1 = { package = "embedded-hal", version = "1.0" }
 embedded-hal-async = { version = "1.0" }
 
-futures-util = { version = "0.3.17", default-features = false }
+futures-util = { version = "0.3.17", default-features = false, optional = true }
 critical-section = "1.1"
 cfg-if = "1.0.0"
 

embassy-time/src/timer.rs

@@ -2,8 +2,8 @@ use core::future::{poll_fn, Future};
 use core::pin::Pin;
 use core::task::{Context, Poll};
 
-use futures_util::stream::FusedStream;
-use futures_util::Stream;
+#[cfg(feature = "futures-util")]
+use futures_util::{stream::FusedStream, Stream};
 
 use crate::{Duration, Instant};
 
@@ -277,6 +277,7 @@ impl Ticker {
 
 impl Unpin for Ticker {}
 
+#[cfg(feature = "futures-util")]
 impl Stream for Ticker {
     type Item = ();
     fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
@@ -291,6 +292,7 @@ impl Stream for Ticker {
     }
 }
 
+#[cfg(feature = "futures-util")]
 impl FusedStream for Ticker {
     fn is_terminated(&self) -> bool {
         // `Ticker` keeps yielding values until dropped, it never terminates.