Auto merge of #57714 - matthewjasper:wellformed-unreachable, r=pnkfelix

[rust.git] / src / libcore / option.rs

diff --git a/src/libcore/option.rs b/src/libcore/option.rs
index b6af90337dd4571782ee96de87a4972be7d75578..0e54397db02476942bdda8998f04f4447b64a5a4 100644 (file)
--- a/src/libcore/option.rs
+++ b/src/libcore/option.rs
@@ -874,6 +874,48 @@ pub fn replace(&mut self, value: T) -> Option<T> {
     }
 }
 
+impl<'a, T: Copy> Option<&'a T> {
+    /// Maps an `Option<&T>` to an `Option<T>` by copying the contents of the
+    /// option.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(copied)]
+    ///
+    /// let x = 12;
+    /// let opt_x = Some(&x);
+    /// assert_eq!(opt_x, Some(&12));
+    /// let copied = opt_x.copied();
+    /// assert_eq!(copied, Some(12));
+    /// ```
+    #[unstable(feature = "copied", issue = "57126")]
+    pub fn copied(self) -> Option<T> {
+        self.map(|&t| t)
+    }
+}
+
+impl<'a, T: Copy> Option<&'a mut T> {
+    /// Maps an `Option<&mut T>` to an `Option<T>` by copying the contents of the
+    /// option.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(copied)]
+    ///
+    /// let mut x = 12;
+    /// let opt_x = Some(&mut x);
+    /// assert_eq!(opt_x, Some(&mut 12));
+    /// let copied = opt_x.copied();
+    /// assert_eq!(copied, Some(12));
+    /// ```
+    #[unstable(feature = "copied", issue = "57126")]
+    pub fn copied(self) -> Option<T> {
+        self.map(|&mut t| t)
+    }
+}
+
 impl<'a, T: Clone> Option<&'a T> {
     /// Maps an `Option<&T>` to an `Option<T>` by cloning the contents of the
     /// option.
@@ -971,8 +1013,6 @@ impl<T, E> Option<Result<T, E>> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(transpose_result)]
-    ///
     /// #[derive(Debug, Eq, PartialEq)]
     /// struct SomeErr;
     ///
@@ -981,7 +1021,7 @@ impl<T, E> Option<Result<T, E>> {
     /// assert_eq!(x, y.transpose());
     /// ```
     #[inline]
-    #[unstable(feature = "transpose_result", issue = "47338")]
+    #[stable(feature = "transpose_result", since = "1.33.0")]
     pub fn transpose(self) -> Result<Option<T>, E> {
         match self {
             Some(Ok(x)) => Ok(Some(x)),