1 files changed, 62 insertions, 8 deletions

diff --git a/tokio/src/io/driver/interest.rs b/tokio/src/io/driver/interest.rs
index f9887e86..8c8049df 100644
--- a/tokio/src/io/driver/interest.rs
+++ b/tokio/src/io/driver/interest.rs
@@ -1,3 +1,7 @@
+#![cfg_attr(not(feature = "net"), allow(unreachable_pub))]
+
+use crate::io::driver::Ready;
+
 use std::fmt;
 use std::ops;
 
@@ -5,34 +9,84 @@ use std::ops;
 ///
 /// Specifies the readiness events the caller is interested in when awaiting on
 /// I/O resource readiness states.
-#[derive(Clone, Copy)]
-pub(crate) struct Interest(mio::Interest);
+#[cfg_attr(docsrs, doc(cfg(feature = "net")))]
+#[derive(Clone, Copy, Eq, PartialEq)]
+pub struct Interest(mio::Interest);
 
 impl Interest {
-    /// Interest in all readable events
-    pub(crate) const READABLE: Interest = Interest(mio::Interest::READABLE);
+    /// Interest in all readable events.
+    ///
+    /// Readable interest includes read-closed events.
+    pub const READABLE: Interest = Interest(mio::Interest::READABLE);
 
     /// Interest in all writable events
-    pub(crate) const WRITABLE: Interest = Interest(mio::Interest::WRITABLE);
+    ///
+    /// Writable interest includes write-closed events.
+    pub const WRITABLE: Interest = Interest(mio::Interest::WRITABLE);
 
     /// Returns true if the value includes readable interest.
-    pub(crate) const fn is_readable(self) -> bool {
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use tokio::io::Interest;
+    ///
+    /// assert!(Interest::READABLE.is_readable());
+    /// assert!(!Interest::WRITABLE.is_readable());
+    ///
+    /// let both = Interest::READABLE | Interest::WRITABLE;
+    /// assert!(both.is_readable());
+    /// ```
+    pub const fn is_readable(self) -> bool {
         self.0.is_readable()
     }
 
     /// Returns true if the value includes writable interest.
-    pub(crate) const fn is_writable(self) -> bool {
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use tokio::io::Interest;
+    ///
+    /// assert!(!Interest::READABLE.is_writable());
+    /// assert!(Interest::WRITABLE.is_writable());
+    ///
+    /// let both = Interest::READABLE | Interest::WRITABLE;
+    /// assert!(both.is_writable());
+    /// ```
+    pub const fn is_writable(self) -> bool {
         self.0.is_writable()
     }
 
     /// Add together two `Interst` values.
-    pub(crate) const fn add(self, other: Interest) -> Interest {
+    ///
+    /// This function works from a `const` context.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use tokio::io::Interest;
+    ///
+    /// const BOTH: Interest = Interest::READABLE.add(Interest::WRITABLE);
+    ///
+    /// assert!(BOTH.is_readable());
+    /// assert!(BOTH.is_writable());
+    pub const fn add(self, other: Interest) -> Interest {
         Interest(self.0.add(other.0))
     }
 
+    // This function must be crate-private to avoid exposing a `mio` dependency.
     pub(crate) const fn to_mio(self) -> mio::Interest {
         self.0
     }
+
+    pub(super) fn mask(self) -> Ready {
+        match self {
+            Interest::READABLE => Ready::READABLE | Ready::READ_CLOSED,
+            Interest::WRITABLE => Ready::WRITABLE | Ready::WRITE_CLOSED,
+            _ => Ready::EMPTY,
+        }
+    }
 }
 
 impl ops::BitOr for Interest {