The top level message shouldn't be too long; the
replaced-by-coercion/temporary-variable advice can live in a note. Also,
don't mention type ascription when it's not actually available as a real
thing. (The current state of discussion on the type ascription tracking
issue #23416 makes one rather suspect it will never be a stable thing in
its current form, but that's not for us to adjudicate in this commit.)
While we're here, yank out the differentiating parts of the
numeric/other conditional and only have one codepath emitting the
diagnostic.
Rename hir::ExprAgain to hir::ExprContinue
The current name is confusing and historical.
I also used this PR to clean up the annoying indentation in `check/mod.rs`. If that's viewed as too tangential a change, I'll split it up, but it seemed reasonable to slip it in to reduce @bors's work. It's easy to compare for the two commits individually.
r? @petrochenkov
async/await
This PR implements `async`/`await` syntax for `async fn` in Rust 2015 and `async` closures and `async` blocks in Rust 2018 (tracking issue: https://github.com/rust-lang/rust/issues/50547). Limitations: non-`move` async closures with arguments are currently not supported, nor are `async fn` with multiple different input lifetimes. These limitations are not fundamental and will be removed in the future, however I'd like to go ahead and get this PR merged so we can start experimenting with this in combination with futures 0.3.
Based on https://github.com/rust-lang/rust/pull/51414.
cc @petrochenkov for parsing changes.
r? @eddyb
This is gated on edition 2018 & the `async_await` feature gate.
The parser will accept `async fn` and `async unsafe fn` as fn
items. Along the same lines as `const fn`, only `async unsafe fn`
is permitted, not `unsafe async fn`.The parser will not accept
`async` functions as trait methods.
To do a little code clean up, four fields of the function type
struct have been merged into the new `FnHeader` struct: constness,
asyncness, unsafety, and ABI.
Also, a small bug in HIR printing is fixed: it previously printed
`const unsafe fn` as `unsafe const fn`, which is grammatically
incorrect.
do not ICE when existing type info is incomplete
Apparently master is kinda ICE-y right now, but only for some people (sadly that set includes me).
I'm not crazy about this PR, because it seems to regress diagnostics a lot, but it *does* fix the problems. I think probably fixing the diagnostics should be done by doing a better job of suppressing errors?
Mitigates #51683
r? @oli-obk
Add existential type definitions
Note: this does not allow creating named existential types, it just desugars `impl Trait` to a less (but still very) hacky version of actual `existential type` items.
r? @nikomatsakis
rustc: rename ty::maps to ty::query.
Should've never been `maps` but "query system/engine" didn't fully settle from the start.
r? @michaelwoerister or @nikomatsakis
Refactor: Rename ExistentialPredicate::cmp to ExistentialPredicate::stable_cmp
See https://github.com/rust-lang/rust/pull/51276#discussion_r193549404 for
rationale.
Because stable_cmp takes three arguments and Ord::cmp takes two, I am confident that there is no shadowing happening here.
r? @nikomatsakis
