improper_ctypes_definitions: allow `Box`
Addresses https://github.com/rust-lang/rust/pull/72700#issuecomment-659449386.
This PR stops linting against `Box` in `extern "C" fn`s for the `improper_ctypes_definitions` lint - boxes are documented to be FFI-safe.
cc @alexcrichton @CryZe
Compare tagged/niche-filling layout and pick the best one
Finishes up #71045, and so fixes#63866.
cc @eddyb
r? @nikomatsakis (since @eddyb wrote the first commit)
Make some Option methods const
Tracking issue: #67441
Constantify the following methods of `Option`:
- `as_ref`
- `is_some`
- `is_none`
- `iter` (not sure about this one, but it is possible, and will be useful when const traits are a thing)
cc @rust-lang/wg-const-eval @rust-lang/libs
This commit stops linting against `Box` in `extern "C" fn`s for the
`improper_ctypes_definitions` lint - boxes are documented to be
FFI-safe.
Signed-off-by: David Wood <david@davidtw.co>
const generics triage
I went through all const generics issues and closed all issues which are already fixed.
Some issues already have a regression test but were not closed. Also doing this as part of this PR.
uff r? @eddyb @varkor
closes#61936closes#62878closes#63695closes#67144closes#68596closes#69816closes#70217closes#70507closes#70586closes#71348closes#71805closes#73120closes#73508closes#73730closes#74255
Constify most non-trait `Duration` methods as described in #72440
The remaining methods could probably be made const once https://github.com/rust-lang/rust/pull/72449 lands with support for `f<32|64>::is_finite()`.
Update reference to CONTRIBUTING.md
CONTRIBUTING.md has been migrated to the rustc-dev-guide but some still refer there.
Update them with the appropriate links.
Fixes#74253
Handle case of incomplete local ty more gracefully
When encountering a local binding with a type that isn't completed, the
parser will reach a `=` token. When this happen, consider the type
"complete" as far as the parser is concerned to avoid further errors
being emitted by parse recovery logic.
improve DiscriminantKind handling
Adds a lang item `discriminant_type` for the associated type `DiscriminantKind::Discriminant`.
Changes the discriminant of generators from `i32` to `u32`, which should not be observable to fix an
oversight where MIR was using `u32` and codegen and typeck used `i32`.
This now reuses `fn discriminant_ty` in project, removing
some code duplication. Doing so made me realize that
we previously had a disagreement about the discriminant
type of generators, with MIR using `u32` and codegen and
trait selection using `i32`.
We now always use `u32`.
