VecMap::into_iter shouldn't be taking a `&mut self`

[erickt]

cc @gankro

I'm in the process of IntoIter-ifying the collections, and I've discovered that the VecMap::into_iter takes a &mut self instead of the convention of into_* consuming the value. It's also marked stable, even though the type itself is marked unstable. Should this instead be a candidate for the drain method discussed in the collection reform trait?

[Gankra]

Yeah this is just a mistake. Feel free to fix it to match conventions.

[aochagavia]

Just to be clear, the solution to this is to make into_iter consume the value and introduce a drain function (and iterator). Is this right or am I missing something?

[Gankra]

Yep!