X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=src%2Flibcore%2Fborrow.rs;h=3e533255becb5e48a86dd72a5e32686c76ff642a;hb=cdbbc25cc31080e189a98c010a0b39a9074d0c50;hp=89668dc06505b4cb7689a25ccbe2b4c6270bb356;hpb=ccba43df81d5bda37c9e4d231ad4443e6f3a7e44;p=rust.git

diff --git a/src/libcore/borrow.rs b/src/libcore/borrow.rs
index 89668dc0650..3e533255bec 100644
--- a/src/libcore/borrow.rs
+++ b/src/libcore/borrow.rs
@@ -32,6 +32,10 @@
 /// on the identical behavior of these additional trait implementations.
 /// These traits will likely appear as additional trait bounds.
 ///
+/// In particular `Eq`, `Ord` and `Hash` must be equivalent for
+/// borrowed and owned values: `x.borrow() == y.borrow()` should give the
+/// same result as `x == y`.
+///
 /// If generic code merely needs to work for all types that can
 /// provide a reference to related type `T`, it is often better to use
 /// [`AsRef<T>`] as more types can safely implement it.
@@ -185,7 +189,7 @@ pub trait Borrow<Borrowed: ?Sized> {
 ///
 /// [`Borrow<T>`]: trait.Borrow.html
 #[stable(feature = "rust1", since = "1.0.0")]
-pub trait BorrowMut<Borrowed: ?Sized> : Borrow<Borrowed> {
+pub trait BorrowMut<Borrowed: ?Sized>: Borrow<Borrowed> {
     /// Mutably borrows from an owned value.
     ///
     /// # Examples
@@ -207,25 +211,35 @@ pub trait BorrowMut<Borrowed: ?Sized> : Borrow<Borrowed> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> Borrow<T> for T {
-    fn borrow(&self) -> &T { self }
+    fn borrow(&self) -> &T {
+        self
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> BorrowMut<T> for T {
-    fn borrow_mut(&mut self) -> &mut T { self }
+    fn borrow_mut(&mut self) -> &mut T {
+        self
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> Borrow<T> for &T {
-    fn borrow(&self) -> &T { &**self }
+    fn borrow(&self) -> &T {
+        &**self
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> Borrow<T> for &mut T {
-    fn borrow(&self) -> &T { &**self }
+    fn borrow(&self) -> &T {
+        &**self
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> BorrowMut<T> for &mut T {
-    fn borrow_mut(&mut self) -> &mut T { &mut **self }
+    fn borrow_mut(&mut self) -> &mut T {
+        &mut **self
+    }
 }