Revert "Add implementations of last in terms of next_back on a bunch of DoubleEndedIterators."

This reverts commit 3e86cf36b5114f201868bf459934fe346a76a2d4.

5 files changed, 0 insertions, 88 deletions

diff --git a/src/liballoc/collections/binary_heap.rs b/src/liballoc/collections/binary_heap.rs
index c5a0b6e877b..c898f064fd0 100644
--- a/src/liballoc/collections/binary_heap.rs
+++ b/src/liballoc/collections/binary_heap.rs
@@ -1035,11 +1035,6 @@ impl<'a, T> Iterator for Iter<'a, T> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<&'a T> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1095,11 +1090,6 @@ impl<T> Iterator for IntoIter<T> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<T> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1146,11 +1136,6 @@ impl<T> Iterator for Drain<'_, T> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<T> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "drain", since = "1.6.0")]
diff --git a/src/liballoc/collections/btree/map.rs b/src/liballoc/collections/btree/map.rs
index 414abb00ef1..6b079fc87cc 100644
--- a/src/liballoc/collections/btree/map.rs
+++ b/src/liballoc/collections/btree/map.rs
@@ -1193,11 +1193,6 @@ impl<'a, K: 'a, V: 'a> Iterator for Iter<'a, K, V> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         (self.length, Some(self.length))
     }
-
-    #[inline]
-    fn last(mut self) -> Option<(&'a K, &'a V)> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "fused", since = "1.26.0")]
@@ -1258,11 +1253,6 @@ impl<'a, K: 'a, V: 'a> Iterator for IterMut<'a, K, V> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         (self.length, Some(self.length))
     }
-
-    #[inline]
-    fn last(mut self) -> Option<(&'a K, &'a mut V)> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1369,11 +1359,6 @@ impl<K, V> Iterator for IntoIter<K, V> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         (self.length, Some(self.length))
     }
-
-    #[inline]
-    fn last(mut self) -> Option<(K, V)> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1436,11 +1421,6 @@ impl<'a, K, V> Iterator for Keys<'a, K, V> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.inner.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<&'a K> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1478,11 +1458,6 @@ impl<'a, K, V> Iterator for Values<'a, K, V> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.inner.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<&'a V> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1520,11 +1495,6 @@ impl<'a, K, V> Iterator for Range<'a, K, V> {
             unsafe { Some(self.next_unchecked()) }
         }
     }
-
-    #[inline]
-    fn last(mut self) -> Option<(&'a K, &'a V)> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "map_values_mut", since = "1.10.0")]
@@ -1538,11 +1508,6 @@ impl<'a, K, V> Iterator for ValuesMut<'a, K, V> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.inner.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<&'a mut V> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "map_values_mut", since = "1.10.0")]
@@ -1661,11 +1626,6 @@ impl<'a, K, V> Iterator for RangeMut<'a, K, V> {
             unsafe { Some(self.next_unchecked()) }
         }
     }
-
-    #[inline]
-    fn last(mut self) -> Option<(&'a K, &'a mut V)> {
-        self.next_back()
-    }
 }
 
 impl<'a, K, V> RangeMut<'a, K, V> {
diff --git a/src/liballoc/collections/btree/set.rs b/src/liballoc/collections/btree/set.rs
index 6f2467dfd6b..16a96ca19b8 100644
--- a/src/liballoc/collections/btree/set.rs
+++ b/src/liballoc/collections/btree/set.rs
@@ -1019,11 +1019,6 @@ impl<'a, T> Iterator for Iter<'a, T> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<&'a T> {
-        self.next_back()
-    }
 }
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, T> DoubleEndedIterator for Iter<'a, T> {
@@ -1049,11 +1044,6 @@ impl<T> Iterator for IntoIter<T> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<T> {
-        self.next_back()
-    }
 }
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T> DoubleEndedIterator for IntoIter<T> {
@@ -1083,11 +1073,6 @@ impl<'a, T> Iterator for Range<'a, T> {
     fn next(&mut self) -> Option<&'a T> {
         self.iter.next().map(|(k, _)| k)
     }
-
-    #[inline]
-    fn last(mut self) -> Option<&'a T> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "btree_range", since = "1.17.0")]
diff --git a/src/liballoc/string.rs b/src/liballoc/string.rs
index e74d37c1c2b..7f7722548f5 100644
--- a/src/liballoc/string.rs
+++ b/src/liballoc/string.rs
@@ -2385,10 +2385,6 @@ impl Iterator for Drain<'_> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
-    #[inline]
-    fn last(mut self) -> Option<char> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "drain", since = "1.6.0")]
diff --git a/src/liballoc/vec.rs b/src/liballoc/vec.rs
index c0cdffe596b..073d3ab5937 100644
--- a/src/liballoc/vec.rs
+++ b/src/liballoc/vec.rs
@@ -2395,11 +2395,6 @@ impl<T> Iterator for IntoIter<T> {
     fn count(self) -> usize {
         self.len()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<T> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -2519,11 +2514,6 @@ impl<T> Iterator for Drain<'_, T> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<T> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "drain", since = "1.6.0")]
@@ -2593,10 +2583,6 @@ impl<I: Iterator> Iterator for Splice<'_, I> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.drain.size_hint()
     }
-
-    fn last(mut self) -> Option<Self::Item> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "vec_splice", since = "1.21.0")]