future: add adapters of CancellationToken for FutureExt (#7475)

tokio-util/src/time/mod.rs

@@ -8,45 +8,19 @@
 //!
 //! This type must be used from within the context of the `Runtime`.
 
-use std::future::Future;
 use std::time::Duration;
-use tokio::time::Timeout;
 
 mod wheel;
 
 pub mod delay_queue;
 
+// re-export `FutureExt` to avoid breaking change
+#[doc(inline)]
+pub use crate::future::FutureExt;
+
 #[doc(inline)]
 pub use delay_queue::DelayQueue;
 
-/// A trait which contains a variety of convenient adapters and utilities for `Future`s.
-pub trait FutureExt: Future {
-    /// A wrapper around [`tokio::time::timeout`], with the advantage that it is easier to write
-    /// fluent call chains.
-    ///
-    /// # Examples
-    ///
-    /// ```rust
-    /// use tokio::{sync::oneshot, time::Duration};
-    /// use tokio_util::time::FutureExt;
-    ///
-    /// # async fn dox() {
-    /// let (tx, rx) = oneshot::channel::<()>();
-    ///
-    /// let res = rx.timeout(Duration::from_millis(10)).await;
-    /// assert!(res.is_err());
-    /// # }
-    /// ```
-    fn timeout(self, timeout: Duration) -> Timeout<Self>
-    where
-        Self: Sized,
-    {
-        tokio::time::timeout(timeout, self)
-    }
-}
-
-impl<T: Future + ?Sized> FutureExt for T {}
-
 // ===== Internal utils =====
 
 enum Round {