Remove async-std support (RIP)

futures/src/backend/native/async_std.rs

@@ -1,56 +0,0 @@
-//! An `async-std` backend.
-
-/// An `async-std` executor.
-#[derive(Debug)]
-pub struct Executor;
-
-impl crate::Executor for Executor {
-    fn new() -> Result<Self, futures::io::Error> {
-        Ok(Self)
-    }
-
-    #[allow(clippy::let_underscore_future)]
-    fn spawn(&self, future: impl Future<Output = ()> + Send + 'static) {
-        let _ = async_std::task::spawn(future);
-    }
-}
-
-pub mod time {
-    //! Listen and react to time.
-    use crate::subscription::{self, Hasher, Subscription};
-
-    /// Returns a [`Subscription`] that produces messages at a set interval.
-    ///
-    /// The first message is produced after a `duration`, and then continues to
-    /// produce more messages every `duration` after that.
-    pub fn every(
-        duration: std::time::Duration,
-    ) -> Subscription<std::time::Instant> {
-        subscription::from_recipe(Every(duration))
-    }
-
-    #[derive(Debug)]
-    struct Every(std::time::Duration);
-
-    impl subscription::Recipe for Every {
-        type Output = std::time::Instant;
-
-        fn hash(&self, state: &mut Hasher) {
-            use std::hash::Hash;
-
-            std::any::TypeId::of::<Self>().hash(state);
-            self.0.hash(state);
-        }
-
-        fn stream(
-            self: Box<Self>,
-            _input: subscription::EventStream,
-        ) -> futures::stream::BoxStream<'static, Self::Output> {
-            use futures::stream::StreamExt;
-
-            async_std::stream::interval(self.0)
-                .map(|_| std::time::Instant::now())
-                .boxed()
-        }
-    }
-}