Auto merge of #27 - nipunn1313:extend, r=nox

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

VecLike naturally supports push, so it also makes sense to support extend. Both implementors SmallVec and Vec already have tested implementations, so this extension feels natural.

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lib.rs

@@ -30,7 +30,8 @@ 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);