I ended up altering the semantics of Json's PartialOrd implementation.
It used to be the case that Null < Null, but I can't think of any reason
for an ordering other than the default one so I just switched it over to
using the derived implementation.
This also fixes broken `PartialOrd` implementations for `Vec` and
`TreeMap`.
RFC: 0028-partial-cmp
The following features have been removed
* box [a, b, c]
* ~[a, b, c]
* box [a, ..N]
* ~[a, ..N]
* ~[T] (as a type)
* deprecated_owned_vector lint
All users of ~[T] should move to using Vec<T> instead.
for `~str`/`~[]`.
Note that `~self` still remains, since I forgot to add support for
`Box<self>` before the snapshot.
How to update your code:
* Instead of `~EXPR`, you should write `box EXPR`.
* Instead of `~TYPE`, you should write `Box<Type>`.
* Instead of `~PATTERN`, you should write `box PATTERN`.
[breaking-change]
Namely:
* Added conversion traits both to and from the various vector types,
analogous to how `str::MaybeOwned` works with `str::IntoMaybeOwned`
and `str::Str`. This led me to add the `FixedLen` variant of
`MaybeOwnedVector` for interoperability with `std::slice`.
* Revised client example code to make use of `into_maybe_owned`
* Added implementations of `Show` and `CloneableVector` for
`MaybeOwnedVector`.
* As suggested by kballard, added `into_vec` method that is analogous
to `CloneableVector::into_owned` except it produces a `Vec` rather
than a `~[T]`.
