bors 4a397dd33d Auto merge of #25989 - jooert:implement_rfc839, r=Gankro
I had to use `impl<'a, V: Copy> Extend<(usize, &'a V)> for VecMap<V>` instead of `impl<'a, V: Copy> Extend<(&'a usize, &'a V)> for VecMap<V>` as that's what is needed for doing

```rust
let mut a = VecMap::new();
let b = VecMap::new();
b.insert(1, "foo");

a.extend(&b)
```

I can squash the commits after review.

r? @Gankro
2015-06-08 16:09:56 +00:00
..
2015-06-04 18:03:51 -04:00
2015-06-08 12:05:33 +02:00