Turn `INCOMPLETE_FEATURES` into lint
We do this because it is annoying to see the warning when building rustc and because this is better from a "separation of concerns" POV.
The drawback to this change is that this will respect `--cap-lints`.
Also note that this is not a buffered lint so if there are fatal parser errors then the lint will not trigger.
r? @varkor
Add `impl<T> FromIterator<T> for Arc/Rc<[T]>`
Add implementations of `FromIterator<T> for Arc/Rc<[T]>` with symmetrical logic.
This also takes advantage of specialization in the case of iterators with known length (`TrustedLen`) to elide the final allocation/copying from a `Vec<T>` into `Rc<[T]>` because we can allocate the space for the `Rc<[T]>` directly when the size is known. This is the primary motivation and why this is to be preferred over `iter.collect::<Vec<_>>().into(): Rc<[T]>`.
Moreover, this PR does some refactoring in some places.
r? @RalfJung for the code
cc @alexcrichton from T-libs
Implement specialized nth_back() for Box and Windows.
Hi there, this is my first pull request to rust :-)
I started implementing some specializations for DoubleEndedIterator::nth_back() and these are the first two. The problem has been discussed in #54054 and nth_back() is tracked in #56995.
I'm stuck with the next implementation so I though I do a PR for the ones I'm confident with to get some feedback.
split MaybeUninit into several features, expand docs a bit
This splits the `maybe_uninit` feature gate into several:
* `maybe_uninit` for what we will hopefully stabilize soon-ish.
* `maybe_uninit_ref` for creating references into `MaybeUninit`, for which the rules are not yet clear.
* `maybe_uninit_slice` for handling slices of `MaybeUninit`, which needs more API design work.
* `maybe_uninit_array` for creating arrays of `MaybeUninit` using a macro (because we don't have https://github.com/rust-lang/rust/issues/49147 yet).
Is that an okay thing to do? The goal is to help people avoid APIs we do not want to stabilize yet. I used this to make sure rustc itself does not use `get_ref` and `get_mut`.
I also extended the docs to advise against uninitialized integers -- again this is something for which the rules are still being discussed.
This change updates the future and task API as discussed in the stabilization RFC at https://github.com/rust-lang/rfcs/pull/2592.
Changes:
- Replacing UnsafeWake with RawWaker and RawWakerVtable
- Removal of LocalWaker
- Removal of Arc-based Wake trait
Transition liballoc to Rust 2018
This transitions liballoc to Rust 2018 edition and applies relevant idiom lints.
I also did a small bit of drive-by cleanup along the way.
r? @oli-obk
I started with liballoc since it seemed easiest. In particular, adding `edition = "2018"` to libcore gave me way too many errors due to stdsimd. Ideally we should be able to continue this crate-by-crate until all crates use 2018.
Pin stabilization
This implements the changes suggested in https://github.com/rust-lang/rust/issues/55766#issue-378417538 and stabilizes the `pin` feature. @alexcrichton also listed several "blockers" in that issue, but then in [this comment](https://github.com/rust-lang/rust/issues/55766#issuecomment-445074980) mentioned that they're more "TODO items":
> In that vein I think it's fine for a stabilization PR to be posted at any time now with FCP lapsed for a week or so now. The final points about self/pin/pinned can be briefly discussed there (if even necessary, they could be left as the proposal above).
Let's settle these last bits here and get this thing stabilized! :)
r? @alexcrichton
cc @withoutboats
deny intra-doc link resolution failures in libstd
Fixes#56693.
Until we land a fix for the underlying issue (#56922), we can at least fix the failures in libstd so they don't propagate to downstream crates.
This lets you write methods using `self: Rc<Self>`, `self: Arc<Self>`, `self: Pin<&mut Self>`, `self: Pin<Box<Self>`, and other combinations involving `Pin` and another stdlib receiver type, without needing the `arbitrary_self_types`. Other user-created receiver types can be used, but they still require the feature flag to use.
This is implemented by introducing a new trait, `Receiver`, which the method receiver's type must implement if the `arbitrary_self_types` feature is not enabled. To keep composed receiver types such as `&Arc<Self>` unstable, the receiver type is also required to implement `Deref<Target=Self>` when the feature flag is not enabled.
This lets you use `self: Rc<Self>` and `self: Arc<Self>` in stable Rust, which was not allowed previously. It was agreed that they would be stabilized in #55786. `self: Pin<&Self>` and other pinned receiver types do not require the `arbitrary_self_types` feature, but they cannot be used on stable because `Pin` still requires the `pin` feature.
