From c408b7863389aa2bdb253ffa363e693bcd02439f Mon Sep 17 00:00:00 2001
From: Simon Sapin <simon.sapin@exyr.org>
Date: Wed, 19 Aug 2015 16:03:59 +0200
Subject: [PATCH] Move the Borrow and BorrowMut traits to libcore.
---
src/liballoc/arc.rs | 5 ++
src/liballoc/boxed.rs | 8 +++
src/liballoc/rc.rs | 5 ++
src/libcollections/borrow.rs | 111 +----------------------------------
src/libcore/borrow.rs | 109 ++++++++++++++++++++++++++++++++++
src/libcore/lib.rs | 1 +
6 files changed, 129 insertions(+), 110 deletions(-)
create mode 100644 src/libcore/borrow.rs
diff --git a/src/liballoc/arc.rs b/src/liballoc/arc.rs
index bb2daa2a1d7..b68d7976540 100644
--- a/src/liballoc/arc.rs
+++ b/src/liballoc/arc.rs
@@ -73,6 +73,7 @@ use boxed::Box;
use core::sync::atomic;
use core::sync::atomic::Ordering::{Relaxed, Release, Acquire, SeqCst};
+use core::borrow;
use core::fmt;
use core::cmp::Ordering;
use core::mem::{align_of_val, size_of_val};
@@ -1109,3 +1110,7 @@ mod tests {
assert!(y.upgrade().is_none());
}
}
+
+impl<T: ?Sized> borrow::Borrow<T> for Arc<T> {
+ fn borrow(&self) -> &T { &**self }
+}
diff --git a/src/liballoc/boxed.rs b/src/liballoc/boxed.rs
index e3019f952fe..a6e0f3a9bd9 100644
--- a/src/liballoc/boxed.rs
+++ b/src/liballoc/boxed.rs
@@ -57,6 +57,7 @@ use heap;
use raw_vec::RawVec;
use core::any::Any;
+use core::borrow;
use core::cmp::Ordering;
use core::fmt;
use core::hash::{self, Hash};
@@ -562,3 +563,10 @@ impl<T: Clone> Clone for Box<[T]> {
}
}
+impl<T: ?Sized> borrow::Borrow<T> for Box<T> {
+ fn borrow(&self) -> &T { &**self }
+}
+
+impl<T: ?Sized> borrow::BorrowMut<T> for Box<T> {
+ fn borrow_mut(&mut self) -> &mut T { &mut **self }
+}
diff --git a/src/liballoc/rc.rs b/src/liballoc/rc.rs
index 9649d0f71a1..b1fb5be4d21 100644
--- a/src/liballoc/rc.rs
+++ b/src/liballoc/rc.rs
@@ -158,6 +158,7 @@ use boxed::Box;
#[cfg(test)]
use std::boxed::Box;
+use core::borrow;
use core::cell::Cell;
use core::cmp::Ordering;
use core::fmt;
@@ -1091,3 +1092,7 @@ mod tests {
assert_eq!(foo, foo.clone());
}
}
+
+impl<T: ?Sized> borrow::Borrow<T> for Rc<T> {
+ fn borrow(&self) -> &T { &**self }
+}
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 {
diff --git a/src/libcore/borrow.rs b/src/libcore/borrow.rs
new file mode 100644
index 00000000000..79330d3a61e
--- /dev/null
+++ b/src/libcore/borrow.rs
@@ -0,0 +1,109 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! A module for working with borrowed data.
+
+#![stable(feature = "rust1", since = "1.0.0")]
+
+use marker::Sized;
+
+/// 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 }
+}
diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
index 551ea233f76..78a467e3657 100644
--- a/src/libcore/lib.rs
+++ b/src/libcore/lib.rs
@@ -139,6 +139,7 @@ pub mod cmp;
pub mod clone;
pub mod default;
pub mod convert;
+pub mod borrow;
/* Core types and methods on primitives */