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

This reverts commit 3e86cf36b5114f201868bf459934fe346a76a2d4.

1 files changed, 0 insertions, 20 deletions

diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index 0e8a2da3c11..ef4bd83cbc5 100644
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -1333,11 +1333,6 @@ impl<'a> Iterator for Lines<'a> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.0.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<Self::Item> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1384,11 +1379,6 @@ impl<'a> Iterator for LinesAny<'a> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.0.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<Self::Item> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -4231,11 +4221,6 @@ impl<'a> Iterator for SplitWhitespace<'a> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.inner.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<Self::Item> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "split_whitespace", since = "1.1.0")]
@@ -4262,11 +4247,6 @@ impl<'a> Iterator for SplitAsciiWhitespace<'a> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.inner.size_hint()
     }
-
-    #[inline]
-    fn last(mut self) -> Option<Self::Item> {
-        self.next_back()
-    }
 }
 
 #[stable(feature = "split_ascii_whitespace", since = "1.34.0")]