Move the Borrow and BorrowMut traits to libcore.

1 files changed, 1 insertions, 110 deletions

diff --git a/src/libcollections/borrow.rs b/src/libcollections/borrow.rs
index bfd06915250..bd1864b28cd 100644
--- a/src/libcollections/borrow.rs
+++ b/src/libcollections/borrow.rs
@@ -21,119 +21,10 @@ use core::ops::Deref;
 use core::option::Option;
 
 use fmt;
-use alloc::{boxed, rc, arc};
 
 use self::Cow::*;
 
-/// A trait for borrowing data.
-///
-/// In general, there may be several ways to "borrow" a piece of data.  The
-/// typical ways of borrowing a type `T` are `&T` (a shared borrow) and `&mut T`
-/// (a mutable borrow). But types like `Vec<T>` provide additional kinds of
-/// borrows: the borrowed slices `&[T]` and `&mut [T]`.
-///
-/// When writing generic code, it is often desirable to abstract over all ways
-/// of borrowing data from a given type. That is the role of the `Borrow`
-/// trait: if `T: Borrow<U>`, then `&U` can be borrowed from `&T`.  A given
-/// type can be borrowed as multiple different types. In particular, `Vec<T>:
-/// Borrow<Vec<T>>` and `Vec<T>: Borrow<[T]>`.
-///
-/// If you are implementing `Borrow` and both `Self` and `Borrowed` implement
-/// `Hash`, `Eq`, and/or `Ord`, they must produce the same result.
-///
-/// `Borrow` is very similar to, but different than, `AsRef`. See
-/// [the book][book] for more.
-///
-/// [book]: ../../book/borrow-and-asref.html
-#[stable(feature = "rust1", since = "1.0.0")]
-pub trait Borrow<Borrowed: ?Sized> {
-    /// Immutably borrows from an owned value.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use std::borrow::Borrow;
-    ///
-    /// fn check<T: Borrow<str>>(s: T) {
-    ///     assert_eq!("Hello", s.borrow());
-    /// }
-    ///
-    /// let s = "Hello".to_string();
-    ///
-    /// check(s);
-    ///
-    /// let s = "Hello";
-    ///
-    /// check(s);
-    /// ```
-    #[stable(feature = "rust1", since = "1.0.0")]
-    fn borrow(&self) -> &Borrowed;
-}
-
-/// A trait for mutably borrowing data.
-///
-/// Similar to `Borrow`, but for mutable borrows.
-#[stable(feature = "rust1", since = "1.0.0")]
-pub trait BorrowMut<Borrowed: ?Sized> : Borrow<Borrowed> {
-    /// Mutably borrows from an owned value.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use std::borrow::BorrowMut;
-    ///
-    /// fn check<T: BorrowMut<[i32]>>(mut v: T) {
-    ///     assert_eq!(&mut [1, 2, 3], v.borrow_mut());
-    /// }
-    ///
-    /// let v = vec![1, 2, 3];
-    ///
-    /// check(v);
-    /// ```
-    #[stable(feature = "rust1", since = "1.0.0")]
-    fn borrow_mut(&mut self) -> &mut Borrowed;
-}
-
-#[stable(feature = "rust1", since = "1.0.0")]
-impl<T: ?Sized> Borrow<T> for T {
-    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 }
-}
-
-#[stable(feature = "rust1", since = "1.0.0")]
-impl<'a, T: ?Sized> Borrow<T> for &'a T {
-    fn borrow(&self) -> &T { &**self }
-}
-
-#[stable(feature = "rust1", since = "1.0.0")]
-impl<'a, T: ?Sized> Borrow<T> for &'a mut T {
-    fn borrow(&self) -> &T { &**self }
-}
-
-#[stable(feature = "rust1", since = "1.0.0")]
-impl<'a, T: ?Sized> BorrowMut<T> for &'a mut T {
-    fn borrow_mut(&mut self) -> &mut T { &mut **self }
-}
-
-impl<T: ?Sized> Borrow<T> for boxed::Box<T> {
-    fn borrow(&self) -> &T { &**self }
-}
-
-impl<T: ?Sized> BorrowMut<T> for boxed::Box<T> {
-    fn borrow_mut(&mut self) -> &mut T { &mut **self }
-}
-
-impl<T: ?Sized> Borrow<T> for rc::Rc<T> {
-    fn borrow(&self) -> &T { &**self }
-}
-
-impl<T: ?Sized> Borrow<T> for arc::Arc<T> {
-    fn borrow(&self) -> &T { &**self }
-}
+pub use core::borrow::{Borrow, BorrowMut};
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, B: ?Sized> Borrow<B> for Cow<'a, B> where B: ToOwned, <B as ToOwned>::Owned: 'a {