Support std::iter::extend<T> for VecLike<T>

Author: nipunn1313

lib.rs

@@ -7,7 +7,7 @@
 
 use std::cmp;
 use std::fmt;
-use std::iter::{IntoIterator, FromIterator};
+use std::iter::{Extend, IntoIterator, FromIterator};
 use std::mem;
 use std::ops;
 use std::ptr;
@@ -28,7 +28,8 @@ pub trait VecLike<T>:
         ops::Index<ops::RangeFull, Output=[T]> +
         ops::IndexMut<ops::RangeFull> +
         ops::Deref +
-        ops::DerefMut {
+        ops::DerefMut +
+        Extend<T> {
 
     fn len(&self) -> usize;
     fn push(&mut self, value: T);
@@ -361,8 +362,8 @@ impl<A: Array> FromIterator<A::Item> for SmallVec<A> {
     }
 }
 
-impl<A: Array> SmallVec<A> {
-    pub fn extend<I: IntoIterator<Item=A::Item>>(&mut self, iterable: I) {
+impl<A: Array> Extend<A::Item> for SmallVec<A> {
+    fn extend<I: IntoIterator<Item=A::Item>>(&mut self, iterable: I) {
         let iter = iterable.into_iter();
         let (lower_size_bound, _) = iter.size_hint();