core: Stabilize FusedIterator

FusedIterator is a marker trait that promises that the implementing
iterator continues to return `None` from `.next()` once it has returned
`None` once (and/or `.next_back()`, if implemented).

The effects of FusedIterator are already widely available through
`.fuse()`, but with stable `FusedIterator`, stable Rust users can
implement this trait for their iterators when appropriate.

10 files changed, 31 insertions, 32 deletions

diff --git a/src/liballoc/binary_heap.rs b/src/liballoc/binary_heap.rs
index 3041f85cd4c..a5694a90dbc 100644
--- a/src/liballoc/binary_heap.rs
+++ b/src/liballoc/binary_heap.rs
@@ -964,7 +964,7 @@ impl<'a, T> ExactSizeIterator for Iter<'a, T> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, T> FusedIterator for Iter<'a, T> {}
 
 /// An owning iterator over the elements of a `BinaryHeap`.
@@ -1019,7 +1019,7 @@ impl<T> ExactSizeIterator for IntoIter<T> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<T> FusedIterator for IntoIter<T> {}
 
 /// A draining iterator over the elements of a `BinaryHeap`.
@@ -1065,7 +1065,7 @@ impl<'a, T: 'a> ExactSizeIterator for Drain<'a, T> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, T: 'a> FusedIterator for Drain<'a, T> {}
 
 #[stable(feature = "binary_heap_extras_15", since = "1.5.0")]
diff --git a/src/liballoc/boxed.rs b/src/liballoc/boxed.rs
index 75a59de337c..6b000b6fa91 100644
--- a/src/liballoc/boxed.rs
+++ b/src/liballoc/boxed.rs
@@ -722,7 +722,7 @@ impl<I: ExactSizeIterator + ?Sized> ExactSizeIterator for Box<I> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<I: FusedIterator + ?Sized> FusedIterator for Box<I> {}
 
 
diff --git a/src/liballoc/btree/map.rs b/src/liballoc/btree/map.rs
index 618ef81fdd9..7b7a6374db9 100644
--- a/src/liballoc/btree/map.rs
+++ b/src/liballoc/btree/map.rs
@@ -1156,7 +1156,7 @@ impl<'a, K: 'a, V: 'a> Iterator for Iter<'a, K, V> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, K, V> FusedIterator for Iter<'a, K, V> {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1235,7 +1235,7 @@ impl<'a, K: 'a, V: 'a> ExactSizeIterator for IterMut<'a, K, V> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, K, V> FusedIterator for IterMut<'a, K, V> {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1365,7 +1365,7 @@ impl<K, V> ExactSizeIterator for IntoIter<K, V> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<K, V> FusedIterator for IntoIter<K, V> {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1395,7 +1395,7 @@ impl<'a, K, V> ExactSizeIterator for Keys<'a, K, V> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, K, V> FusedIterator for Keys<'a, K, V> {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1432,7 +1432,7 @@ impl<'a, K, V> ExactSizeIterator for Values<'a, K, V> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, K, V> FusedIterator for Values<'a, K, V> {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1482,7 +1482,7 @@ impl<'a, K, V> ExactSizeIterator for ValuesMut<'a, K, V> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, K, V> FusedIterator for ValuesMut<'a, K, V> {}
 
 
@@ -1561,7 +1561,7 @@ impl<'a, K, V> Range<'a, K, V> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, K, V> FusedIterator for Range<'a, K, V> {}
 
 #[stable(feature = "btree_range", since = "1.17.0")]
@@ -1630,7 +1630,7 @@ impl<'a, K, V> DoubleEndedIterator for RangeMut<'a, K, V> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, K, V> FusedIterator for RangeMut<'a, K, V> {}
 
 impl<'a, K, V> RangeMut<'a, K, V> {
diff --git a/src/liballoc/btree/set.rs b/src/liballoc/btree/set.rs
index 327eaaf4651..34cb7a08ed7 100644
--- a/src/liballoc/btree/set.rs
+++ b/src/liballoc/btree/set.rs
@@ -946,7 +946,7 @@ impl<'a, T> ExactSizeIterator for Iter<'a, T> {
     fn len(&self) -> usize { self.iter.len() }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, T> FusedIterator for Iter<'a, T> {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -971,7 +971,7 @@ impl<T> ExactSizeIterator for IntoIter<T> {
     fn len(&self) -> usize { self.iter.len() }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<T> FusedIterator for IntoIter<T> {}
 
 #[stable(feature = "btree_range", since = "1.17.0")]
@@ -997,7 +997,7 @@ impl<'a, T> DoubleEndedIterator for Range<'a, T> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, T> FusedIterator for Range<'a, T> {}
 
 /// Compare `x` and `y`, but return `short` if x is None and `long` if y is None
@@ -1044,7 +1044,7 @@ impl<'a, T: Ord> Iterator for Difference<'a, T> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, T: Ord> FusedIterator for Difference<'a, T> {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1078,7 +1078,7 @@ impl<'a, T: Ord> Iterator for SymmetricDifference<'a, T> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, T: Ord> FusedIterator for SymmetricDifference<'a, T> {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1116,7 +1116,7 @@ impl<'a, T: Ord> Iterator for Intersection<'a, T> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, T: Ord> FusedIterator for Intersection<'a, T> {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1150,5 +1150,5 @@ impl<'a, T: Ord> Iterator for Union<'a, T> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, T: Ord> FusedIterator for Union<'a, T> {}
diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs
index d250cfe1880..2212b62dfd8 100644
--- a/src/liballoc/lib.rs
+++ b/src/liballoc/lib.rs
@@ -96,7 +96,6 @@
 #![feature(fmt_internals)]
 #![feature(from_ref)]
 #![feature(fundamental)]
-#![feature(fused)]
 #![feature(generic_param_attrs)]
 #![feature(i128_type)]
 #![feature(inclusive_range)]
@@ -125,7 +124,7 @@
 #![feature(on_unimplemented)]
 #![feature(exact_chunks)]
 
-#![cfg_attr(not(test), feature(fused, fn_traits, placement_new_protocol, swap_with_slice, i128))]
+#![cfg_attr(not(test), feature(fn_traits, placement_new_protocol, swap_with_slice, i128))]
 #![cfg_attr(test, feature(test, box_heap))]
 
 // Allow testing this library
diff --git a/src/liballoc/linked_list.rs b/src/liballoc/linked_list.rs
index ec579e3fd68..87939fddfc8 100644
--- a/src/liballoc/linked_list.rs
+++ b/src/liballoc/linked_list.rs
@@ -897,7 +897,7 @@ impl<'a, T> DoubleEndedIterator for Iter<'a, T> {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, T> ExactSizeIterator for Iter<'a, T> {}
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, T> FusedIterator for Iter<'a, T> {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -946,7 +946,7 @@ impl<'a, T> DoubleEndedIterator for IterMut<'a, T> {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, T> ExactSizeIterator for IterMut<'a, T> {}
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, T> FusedIterator for IterMut<'a, T> {}
 
 impl<'a, T> IterMut<'a, T> {
@@ -1117,7 +1117,7 @@ impl<T> DoubleEndedIterator for IntoIter<T> {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T> ExactSizeIterator for IntoIter<T> {}
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<T> FusedIterator for IntoIter<T> {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/src/liballoc/str.rs b/src/liballoc/str.rs
index a00e3d17dd0..1a431bb2694 100644
--- a/src/liballoc/str.rs
+++ b/src/liballoc/str.rs
@@ -171,7 +171,7 @@ impl<'a> Iterator for EncodeUtf16<'a> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a> FusedIterator for EncodeUtf16<'a> {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/src/liballoc/string.rs b/src/liballoc/string.rs
index 409d2ab287e..1fcabd8a427 100644
--- a/src/liballoc/string.rs
+++ b/src/liballoc/string.rs
@@ -2254,5 +2254,5 @@ impl<'a> DoubleEndedIterator for Drain<'a> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a> FusedIterator for Drain<'a> {}
diff --git a/src/liballoc/vec.rs b/src/liballoc/vec.rs
index 3c9b6b94b44..03c9750fb39 100644
--- a/src/liballoc/vec.rs
+++ b/src/liballoc/vec.rs
@@ -2389,7 +2389,7 @@ impl<T> ExactSizeIterator for IntoIter<T> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<T> FusedIterator for IntoIter<T> {}
 
 #[unstable(feature = "trusted_len", issue = "37572")]
@@ -2495,7 +2495,7 @@ impl<'a, T> ExactSizeIterator for Drain<'a, T> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, T> FusedIterator for Drain<'a, T> {}
 
 /// A place for insertion at the back of a `Vec`.
diff --git a/src/liballoc/vec_deque.rs b/src/liballoc/vec_deque.rs
index 8b686365e69..3d7549abe6f 100644
--- a/src/liballoc/vec_deque.rs
+++ b/src/liballoc/vec_deque.rs
@@ -1991,7 +1991,7 @@ impl<'a, T> ExactSizeIterator for Iter<'a, T> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, T> FusedIterator for Iter<'a, T> {}
 
 
@@ -2084,7 +2084,7 @@ impl<'a, T> ExactSizeIterator for IterMut<'a, T> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, T> FusedIterator for IterMut<'a, T> {}
 
 /// An owning iterator over the elements of a `VecDeque`.
@@ -2140,7 +2140,7 @@ impl<T> ExactSizeIterator for IntoIter<T> {
     }
 }
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<T> FusedIterator for IntoIter<T> {}
 
 /// A draining iterator over the elements of a `VecDeque`.
@@ -2247,7 +2247,7 @@ impl<'a, T: 'a> DoubleEndedIterator for Drain<'a, T> {
 #[stable(feature = "drain", since = "1.6.0")]
 impl<'a, T: 'a> ExactSizeIterator for Drain<'a, T> {}
 
-#[unstable(feature = "fused", issue = "35602")]
+#[stable(feature = "fused", since = "1.25.0")]
 impl<'a, T: 'a> FusedIterator for Drain<'a, T> {}
 
 #[stable(feature = "rust1", since = "1.0.0")]