core: add the `IntoIterator` trait

3 files changed, 51 insertions, 0 deletions

diff --git a/src/libcore/array.rs b/src/libcore/array.rs
index a81615944fb..ec3d9783255 100644
--- a/src/libcore/array.rs
+++ b/src/libcore/array.rs
@@ -18,12 +18,14 @@ use clone::Clone;
 use cmp::{PartialEq, Eq, PartialOrd, Ord, Ordering};
 use fmt;
 use hash::{Hash, Hasher, self};
+use iter::IntoIterator;
 use marker::Copy;
 #[cfg(stage0)]
 use ops::{Deref, FullRange};
 #[cfg(not(stage0))]
 use ops::Deref;
 use option::Option;
+use slice::{Iter, IterMut, SliceExt};
 
 // macro for implementing n-ary tuple functions and operations
 macro_rules! array_impls {
@@ -49,6 +51,22 @@ macro_rules! array_impls {
                 }
             }
 
+            impl<'a, T> IntoIterator for &'a [T; $N] {
+                type Iter = Iter<'a, T>;
+
+                fn into_iter(self) -> Iter<'a, T> {
+                    self.iter()
+                }
+            }
+
+            impl<'a, T> IntoIterator for &'a mut [T; $N] {
+                type Iter = IterMut<'a, T>;
+
+                fn into_iter(self) -> IterMut<'a, T> {
+                    self.iter_mut()
+                }
+            }
+
             #[stable(feature = "rust1", since = "1.0.0")]
             impl<A, B> PartialEq<[B; $N]> for [A; $N] where A: PartialEq<B> {
                 #[inline]
diff --git a/src/libcore/iter.rs b/src/libcore/iter.rs
index b6b2f9c57fe..f9c6e0758e6 100644
--- a/src/libcore/iter.rs
+++ b/src/libcore/iter.rs
@@ -122,6 +122,23 @@ pub trait FromIterator<A> {
     fn from_iter<T: Iterator<Item=A>>(iterator: T) -> Self;
 }
 
+/// Conversion into an `Iterator`
+#[unstable]
+pub trait IntoIterator {
+    type Iter: Iterator;
+
+    /// Consumes `Self` and returns an iterator over it
+    fn into_iter(self) -> Self::Iter;
+}
+
+impl<I> IntoIterator for I where I: Iterator {
+    type Iter = I;
+
+    fn into_iter(self) -> I {
+        self
+    }
+}
+
 /// A type growable from an `Iterator` implementation
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait Extend<A> {
diff --git a/src/libcore/slice.rs b/src/libcore/slice.rs
index 40e66db3ae5..11e3d196f73 100644
--- a/src/libcore/slice.rs
+++ b/src/libcore/slice.rs
@@ -637,6 +637,22 @@ impl<'a, T> Default for &'a [T] {
 // Iterators
 //
 
+impl<'a, T> IntoIterator for &'a [T] {
+    type Iter = Iter<'a, T>;
+
+    fn into_iter(self) -> Iter<'a, T> {
+        self.iter()
+    }
+}
+
+impl<'a, T> IntoIterator for &'a mut [T] {
+    type Iter = IterMut<'a, T>;
+
+    fn into_iter(self) -> IterMut<'a, T> {
+        self.iter_mut()
+    }
+}
+
 // The shared definition of the `Iter` and `IterMut` iterators
 macro_rules! iterator {
     (struct $name:ident -> $ptr:ty, $elem:ty) => {