Rollup merge of #82372 - RalfJung:unsafe-cell, r=KodrAus

[rust.git] / library / core / src / result.rs

diff --git a/library/core/src/result.rs b/library/core/src/result.rs
index a43ba5882edcd704bbeabf6ca730eb3e2221631e..d8747f8b8d6dcb4900af1f98325333cc47cf8586 100644 (file)
--- a/library/core/src/result.rs
+++ b/library/core/src/result.rs
@@ -1276,6 +1276,41 @@ pub fn flatten(self) -> Result<T, E> {
     }
 }
 
+impl<T> Result<T, T> {
+    /// Returns the [`Ok`] value if `self` is `Ok`, and the [`Err`] value if
+    /// `self` is `Err`.
+    ///
+    /// In other words, this function returns the value (the `T`) of a
+    /// `Result<T, T>`, regardless of whether or not that result is `Ok` or
+    /// `Err`.
+    ///
+    /// This can be useful in conjunction with APIs such as
+    /// [`Atomic*::compare_exchange`], or [`slice::binary_search`][binary_search], but only in
+    /// cases where you don't care if the result was `Ok` or not.
+    ///
+    /// [`Atomic*::compare_exchange`]: crate::sync::atomic::AtomicBool::compare_exchange
+    /// [binary_search]: ../../std/primitive.slice.html#method.binary_search
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(result_into_ok_or_err)]
+    /// let ok: Result<u32, u32> = Ok(3);
+    /// let err: Result<u32, u32> = Err(4);
+    ///
+    /// assert_eq!(ok.into_ok_or_err(), 3);
+    /// assert_eq!(err.into_ok_or_err(), 4);
+    /// ```
+    #[inline]
+    #[unstable(feature = "result_into_ok_or_err", reason = "newly added", issue = "82223")]
+    pub const fn into_ok_or_err(self) -> T {
+        match self {
+            Ok(v) => v,
+            Err(v) => v,
+        }
+    }
+}
+
 // This is a separate function to reduce the code size of the methods
 #[inline(never)]
 #[cold]