update libcore to 2016-04-29 nightly

1 files changed, 13 insertions, 0 deletions

diff --git a/libcollections/vec.rs b/libcollections/vec.rs
index dde5cbb..58d4a4e 100644
--- a/libcollections/vec.rs
+++ b/libcollections/vec.rs
@@ -75,6 +75,7 @@ use core::ops;
 use core::ptr;
 use core::slice;
 
+use super::SpecExtend;
 use super::range::RangeArgument;
 
 /// A contiguous growable array type, written `Vec<T>` but pronounced 'vector.'
@@ -1390,10 +1391,22 @@ impl<'a, T> IntoIterator for &'a mut Vec<T> {
 impl<T> Extend<T> for Vec<T> {
     #[inline]
     fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I) {
+        <Self as SpecExtend<I>>::spec_extend(self, iter);
+    }
+}
+
+impl<I: IntoIterator> SpecExtend<I> for Vec<I::Item> {
+    default fn spec_extend(&mut self, iter: I) {
         self.extend_desugared(iter.into_iter())
     }
 }
 
+impl<T> SpecExtend<Vec<T>> for Vec<T> {
+    fn spec_extend(&mut self, ref mut other: Vec<T>) {
+        self.append(other);
+    }
+}
+
 impl<T> Vec<T> {
     fn extend_desugared<I: Iterator<Item = T>>(&mut self, mut iterator: I) {
         // This function should be the moral equivalent of: