rust/compiler/rustc_ast_lowering/src
bors 7402519c63 Auto merge of #109010 - compiler-errors:rtn, r=eholk
Initial support for return type notation (RTN)

See: https://smallcultfollowing.com/babysteps/blog/2023/02/13/return-type-notation-send-bounds-part-2/

1. Only supports `T: Trait<method(): Send>` style bounds, not `<T as Trait>::method(): Send`. Checking validity and injecting an implicit binder for all of the late-bound method generics is harder to do for the latter.
    * I'd add this in a follow-up.
3. ~Doesn't support RTN in general type position, i.e. no `let x: <T as Trait>::method() = ...`~
    * I don't think we actually want this.
5. Doesn't add syntax for "eliding" the function args -- i.e. for now, we write `method(): Send` instead of `method(..): Send`.
    * May be a hazard if we try to add it in the future. I'll probably add it in a follow-up later, with a structured suggestion to change `method()` to `method(..)` once we add it.
7. ~I'm not in love with the feature gate name 😺~
    * I renamed it to `return_type_notation` ✔️

Follow-up PRs will probably add support for `where T::method(): Send` bounds. I'm not sure if we ever want to support return-type-notation in arbitrary type positions. I may also make the bounds require `..` in the args list later.

r? `@ghost`
2023-03-31 18:04:12 +00:00
..
asm.rs Fix uninlined_format_args for some compiler crates 2023-01-05 19:01:12 +01:00
block.rs rustc_ast_lowering: remove ref patterns 2022-11-22 18:49:29 +00:00
errors.rs Add (..) syntax for RTN 2023-03-28 01:14:28 +00:00
expr.rs Remove the NodeId of ast::ExprKind::Async 2023-03-19 19:01:31 +01:00
format.rs Use span of placeholders in format_args!() expansion. 2023-03-27 14:53:48 +02:00
index.rs Take a LocalDefId in hir::Visitor::visit_fn. 2023-01-28 09:51:50 +00:00
item.rs Remove the NodeId of ast::ExprKind::Async 2023-03-19 19:01:31 +01:00
lib.rs Add (..) syntax for RTN 2023-03-28 01:14:28 +00:00
lifetime_collector.rs Rename Rptr to Ref in AST and HIR 2022-12-28 18:52:36 +01:00
pat.rs Add ErrorGuaranteed to HIR ExprKind::Err 2023-02-25 19:46:36 +00:00
path.rs Add (..) syntax for RTN 2023-03-28 01:14:28 +00:00