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Author SHA1 Message Date
bors
454784afba Auto merge of #104048 - cjgillot:split-lifetime, r=compiler-errors 
Separate lifetime ident from lifetime resolution in HIR

Drive-by: change how suggested generic args are computed.
Fixes https://github.com/rust-lang/rust/issues/103815

I recommend reviewing commit-by-commit.
 2022-11-27 14:30:19 +00:00
Maybe Waffle
e143fa2156 nested-match mutability (proposed by the reviewer) 2022-11-24 18:18:45 +00:00
Camille GILLOT
1c737d6997 Use kw::Empty for elided lifetimes in path. 2022-11-24 17:48:59 +00:00
Camille GILLOT
5f5e7a8eec Record in HIR whether lifetime elision was succesful. 2022-11-24 17:48:27 +00:00
Maybe Waffle
da40965300 Add Mutability::{is_mut,is_not} 2022-11-23 20:26:31 +00:00
Camille GILLOT
fb7d25e978 Separate lifetime ident from resolution in HIR. 2022-11-23 19:33:06 +00:00
Dylan DPC
c03026a7c6 Rollup merge of #104721 - WaffleLapkin:deref-harder, r=oli-obk 
Remove more `ref` patterns from the compiler

r? `@oli-obk`
Previous PR: https://github.com/rust-lang/rust/pull/104500
 2022-11-23 20:32:37 +05:30
Maybe Waffle
b97ec3924d rustc_ast_lowering: remove ref patterns 2022-11-22 18:49:29 +00:00
Dylan DPC
88542a3150 Rollup merge of #104615 - spastorino:create-async-def-id-in-lowering, r=compiler-errors 
Create def_id for async fns during lowering

r? `@compiler-errors`
 2022-11-22 16:36:37 +05:30
Nicholas Nethercote
3e3a4192d8 Split MacArgs in two. 
`MacArgs` is an enum with three variants: `Empty`, `Delimited`, and `Eq`. It's
used in two ways:
- For representing attribute macro arguments (e.g. in `AttrItem`), where all
  three variants are used.
- For representing function-like macros (e.g. in `MacCall` and `MacroDef`),
  where only the `Delimited` variant is used.

In other words, `MacArgs` is used in two quite different places due to them
having partial overlap. I find this makes the code hard to read. It also leads
to various unreachable code paths, and allows invalid values (such as
accidentally using `MacArgs::Empty` in a `MacCall`).

This commit splits `MacArgs` in two:
- `DelimArgs` is a new struct just for the "delimited arguments" case. It is
  now used in `MacCall` and `MacroDef`.
- `AttrArgs` is a renaming of the old `MacArgs` enum for the attribute macro
  case. Its `Delimited` variant now contains a `DelimArgs`.

Various other related things are renamed as well.

These changes make the code clearer, avoids several unreachable paths, and
disallows the invalid values.
 2022-11-22 09:04:15 +11:00
bors
7fe6f36224 Auto merge of #103491 - cjgillot:self-rpit, r=oli-obk 
Support using `Self` or projections inside an RPIT/async fn

I reuse the same idea as https://github.com/rust-lang/rust/pull/103449 to use variances to encode whether a lifetime parameter is captured by impl-trait.

The current implementation of async and RPIT replace all lifetimes from the parent generics by `'static`.  This PR changes the scheme
```rust
impl<'a> Foo<'a> {
    fn foo<'b, T>() -> impl Into<Self> + 'b { ... }
}

opaque Foo::<'_a>::foo::<'_b, T>::opaque<'b>: Into<Foo<'_a>> + 'b;
impl<'a> Foo<'a> {
    // OLD
    fn foo<'b, T>() -> Foo::<'static>::foo::<'static, T>::opaque::<'b> { ... }
                             ^^^^^^^ the `Self` becomes `Foo<'static>`

    // NEW
    fn foo<'b, T>() -> Foo::<'a>::foo::<'b, T>::opaque::<'b> { ... }
                             ^^ the `Self` stays `Foo<'a>`
}
```

There is the same issue with projections. In the example, substitute `Self` by `<T as Trait<'b>>::Assoc` in the sugared version, and `Foo<'_a>` by `<T as Trait<'_b>>::Assoc` in the desugared one.

This allows to support `Self` in impl-trait, since we do not replace lifetimes by `'static` any more.  The same trick allows to use projections like `T::Assoc` where `Self` is allowed.  The feature is gated behind a `impl_trait_projections` feature gate.

The implementation relies on 2 tweaking rules for opaques in 2 places:
- we only relate substs that correspond to captured lifetimes during TypeRelation;
- we only list captured lifetimes in choice region computation.

For simplicity, I encoded the "capturedness" of lifetimes as a variance, `Bivariant` vs `Invariant` for unused vs captured lifetimes. The `variances_of` query used to ICE for opaques.

Impl-trait that do not reference `Self` or projections will have their variances as:
- `o` (invariant) for each parent type or const;
- `*` (bivariant) for each parent lifetime --> will not participate in borrowck;
- `o` (invariant) for each own lifetime.

Impl-trait that does reference `Self` and/or projections will have some parent lifetimes marked as `o` (as the example above), and participate in type relation and borrowck.  In the example above, `variances_of(opaque) = ['_a: o, '_b: *, T: o, 'b: o]`.

r? types
cc `@compiler-errors` , as you asked about the issue with `Self` and projections.
 2022-11-21 12:17:03 +00:00
Santiago Pastorino
520fafe5c2 Create def_id for async fns during lowering 2022-11-19 19:17:14 -03:00
bors
70fe5f08ff Auto merge of #101562 - nnethercote:shrink-ast-Expr-harder, r=petrochenkov 
Shrink `ast::Expr` harder

r? `@ghost`
 2022-11-18 16:56:12 +00:00
bors
fd3bfb3551 Auto merge of #104330 - CastilloDel:ast_lowering, r=cjgillot 
Remove allow(rustc::potential_query_instability) from rustc_ast_lowering

Related to https://github.com/rust-lang/rust/issues/84447.

`@cjgillot` Thanks for helping me!
 2022-11-18 13:12:18 +00:00
bors
7c75fe4c85 Auto merge of #104170 - cjgillot:hir-def-id, r=fee1-dead 
Record `LocalDefId` in HIR nodes instead of a side table

This is part of an attempt to remove the `HirId -> LocalDefId` table from HIR.
This attempt is a prerequisite to creation of `LocalDefId` after HIR lowering (https://github.com/rust-lang/rust/pull/96840), by controlling how `def_id` information is accessed.

This first part adds the information to HIR nodes themselves instead of a table.
The second part is https://github.com/rust-lang/rust/pull/103902
The third part will be to make `hir::Visitor::visit_fn` take a `LocalDefId` as last parameter.
The fourth part will be to completely remove the side table.
 2022-11-17 07:42:27 +00:00
Nicholas Nethercote
6b7ca2fcf2 Box ExprKind::{Closure,MethodCall}, and QSelf in expressions, types, and patterns. 2022-11-17 13:45:59 +11:00
Nicholas Nethercote
358a603f11 Use token::Lit in ast::ExprKind::Lit. 
Instead of `ast::Lit`.

Literal lowering now happens at two different times. Expression literals
are lowered when HIR is crated. Attribute literals are lowered during
parsing.

This commit changes the language very slightly. Some programs that used
to not compile now will compile. This is because some invalid literals
that are removed by `cfg` or attribute macros will no longer trigger
errors. See this comment for more details:
https://github.com/rust-lang/rust/pull/102944#issuecomment-1277476773
 2022-11-16 09:41:28 +11:00
CastilloDel
fdb5fe2ed8 Change LoweringContext.children to Vec 2022-11-15 13:57:24 +01:00
CastilloDel
769cc733b1 Remove allow(rustc::potential_query_instability) from rustc_ast_lowering 2022-11-15 13:57:24 +01:00
Camille GILLOT
607d0c2a14 Store a LocalDefId in hir::AnonConst. 2022-11-13 14:06:11 +00:00
Camille GILLOT
18482f7b23 Store a LocalDefId in hir::GenericParam. 2022-11-13 14:05:30 +00:00
Camille GILLOT
c5949c8bee Create bidirectional bounds between original and duplicated parameters. 2022-11-13 09:01:29 +00:00
Nicholas Nethercote
c8c25ce5a1 Rename some OwnerId fields. 
spastorino noticed some silly expressions like `item_id.def_id.def_id`.

This commit renames several `def_id: OwnerId` fields as `owner_id`, so
those expressions become `item_id.owner_id.def_id`.

`item_id.owner_id.local_def_id` would be even clearer, but the use of
`def_id` for values of type `LocalDefId` is *very* widespread, so I left
that alone.
 2022-10-29 20:28:38 +11:00
Santiago Pastorino
49ce8a22b0 Do anonymous lifetimes remapping correctly for nested rpits 2022-10-19 16:49:39 -03:00
Santiago Pastorino
fb5475887f Extract orig_opt_local_def_id as a function 2022-10-19 16:49:39 -03:00
bors
46244f335b Auto merge of #99292 - Aaron1011:stability-use-tree, r=cjgillot 
Correctly handle path stability for 'use tree' items

PR #95956 started checking the stability of path segments.
However, this was not applied to 'use tree' items
(e.g. 'use some::path::{ItemOne, ItemTwo}') due to the way
that we desugar these items in HIR lowering.

This PR modifies 'use tree' lowering to preserve resolution
information, which is needed by stability checking.
 2022-10-15 04:27:15 +00:00
Vadim Petrochenkov
1a8f177772 rustc_hir: Less error-prone methods for accessing PartialRes resolution 2022-10-11 09:04:52 +04:00
Santiago Pastorino
b2bef02bcd create def ids for impl traits during ast lowering 2022-09-30 15:12:01 -03:00
Pietro Albini
3975d55d98 remove cfg(bootstrap) 2022-09-26 10:14:45 +02:00
Takayuki Maeda
8fe936099a separate definitions and HIR owners 
fix a ui test

use `into`

fix clippy ui test

fix a run-make-fulldeps test

implement `IntoQueryParam<DefId>` for `OwnerId`

use `OwnerId` for more queries

change the type of `ParentOwnerIterator::Item` to `(OwnerId, OwnerNode)`
 2022-09-24 23:21:19 +09:00
Dan Johnson
d0a07495be Split out async_fn_in_trait into a separate feature 
PR #101224 added support for async fn in trait desuraging behind the
return_position_impl_trait_in_trait feature.

Split this out so that it's behind its own feature gate, since async fn
in trait doesn't need to follow the same stabilization schedule.
 2022-09-21 19:26:23 -07:00
Santiago Pastorino
550bd0945f Simplify rpitit handling on lower_fn_decl 2022-09-19 09:30:39 -03:00
Dylan DPC
3ad81e0dd8 Rollup merge of #93628 - est31:stabilize_let_else, r=joshtriplett 
Stabilize `let else`

🎉  **Stabilizes the `let else` feature, added by [RFC 3137](https://github.com/rust-lang/rfcs/pull/3137).** 🎉

Reference PR: https://github.com/rust-lang/reference/pull/1156

closes #87335 (`let else` tracking issue)

FCP: https://github.com/rust-lang/rust/pull/93628#issuecomment-1029383585

----------

## Stabilization report

### Summary

The feature allows refutable patterns in `let` statements if the expression is
followed by a diverging `else`:

```Rust
fn get_count_item(s: &str) -> (u64, &str) {
    let mut it = s.split(' ');
    let (Some(count_str), Some(item)) = (it.next(), it.next()) else {
        panic!("Can't segment count item pair: '{s}'");
    };
    let Ok(count) = u64::from_str(count_str) else {
        panic!("Can't parse integer: '{count_str}'");
    };
    (count, item)
}
assert_eq!(get_count_item("3 chairs"), (3, "chairs"));
```

### Differences from the RFC / Desugaring

Outside of desugaring I'm not aware of any differences between the implementation and the RFC. The chosen desugaring has been changed from the RFC's [original](https://rust-lang.github.io/rfcs/3137-let-else.html#reference-level-explanations). You can read a detailed discussion of the implementation history of it in `@cormacrelf` 's [summary](https://github.com/rust-lang/rust/pull/93628#issuecomment-1041143670) in this thread, as well as the [followup](https://github.com/rust-lang/rust/pull/93628#issuecomment-1046598419). Since that followup, further changes have happened to the desugaring, in #98574, #99518, #99954. The later changes were mostly about the drop order: On match, temporaries drop in the same order as they would for a `let` declaration. On mismatch, temporaries drop before the `else` block.

### Test cases

In chronological order as they were merged.

Added by df9a2e0687 (#87688):

* [`ui/pattern/usefulness/top-level-alternation.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/pattern/usefulness/top-level-alternation.rs) to ensure the unreachable pattern lint visits patterns inside `let else`.

Added by 5b95df4bdc (#87688):

* [`ui/let-else/let-else-bool-binop-init.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-bool-binop-init.rs) to ensure that no lazy boolean expressions (using `&&` or `||`) are allowed in the expression, as the RFC mandates.
* [`ui/let-else/let-else-brace-before-else.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-brace-before-else.rs) to ensure that no `}` directly preceding the `else` is allowed in the expression, as the RFC mandates.
* [`ui/let-else/let-else-check.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-check.rs) to ensure that `#[allow(...)]` attributes added to the entire `let` statement apply for the `else` block.
* [`ui/let-else/let-else-irrefutable.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-irrefutable.rs) to ensure that the `irrefutable_let_patterns` lint fires.
* [`ui/let-else/let-else-missing-semicolon.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-missing-semicolon.rs) to ensure the presence of semicolons at the end of the `let` statement.
* [`ui/let-else/let-else-non-diverging.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-non-diverging.rs) to ensure the `else` block diverges.
* [`ui/let-else/let-else-run-pass.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-run-pass.rs) to ensure the feature works in some simple test case settings.
* [`ui/let-else/let-else-scope.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-scope.rs) to ensure the bindings created by the outer `let` expression are not available in the `else` block of it.

Added by bf7c32a447 (#89965):

* [`ui/let-else/issue-89960.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/issue-89960.rs) as a regression test for the ICE-on-error bug #89960 . Later in 102b9125e1 this got removed in favour of more comprehensive tests.

Added by 856541963c (#89974):

* [`ui/let-else/let-else-if.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-if.rs) to test for the improved error message that points out that `let else if` is not possible.

Added by 9b45713b6c:

* [`ui/let-else/let-else-allow-unused.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-allow-unused.rs) as a regression test for #89807, to ensure that `#[allow(...)]` attributes added to the entire `let` statement apply for bindings created by the `let else` pattern.

Added by 61bcd8d307 (#89841):

* [`ui/let-else/let-else-non-copy.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-non-copy.rs) to ensure that a copy is performed out of non-copy wrapper types. This mirrors `if let` behaviour. The test case bases on rustc internal changes originally meant for #89933 but then removed from the PR due to the error prior to the improvements of #89841.
* [`ui/let-else/let-else-source-expr-nomove-pass.rs `](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-source-expr-nomove-pass.rs) to ensure that while there is a move of the binding in the successful case, the `else` case can still access the non-matching value. This mirrors `if let` behaviour.

Added by 102b9125e1 (#89841):

* [`ui/let-else/let-else-ref-bindings.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-ref-bindings.rs) and [`ui/let-else/let-else-ref-bindings-pass.rs `](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-ref-bindings-pass.rs) to check `ref` and `ref mut` keywords in the pattern work correctly and error when needed.

Added by 2715c5f984 (#89841):

* Match ergonomic tests adapted from the `rfc2005` test suite.

Added by fec8a507a2 (#89841):

* [`ui/let-else/let-else-deref-coercion-annotated.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-deref-coercion-annotated.rs) and [`ui/let-else/let-else-deref-coercion.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-deref-coercion.rs) to check deref coercions.

#### Added since this stabilization report was originally written (2022-02-09)

Added by 76ea566677 (#94211):

* [`ui/let-else/let-else-destructuring.rs`](https://github.com/rust-lang/rust/blob/1.63.0/src/test/ui/let-else/let-else-destructuring.rs) to give a nice error message if an user tries to do an assignment with a (possibly refutable) pattern and an `else` block, like asked for in #93995.

Added by e7730dcb7e (#94208):

* [`ui/let-else/let-else-allow-in-expr.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-allow-in-expr.rs) to test whether `#[allow(unused_variables)]` works in the expr, as well as its non presence, as well as putting it on the entire `let else` *affects* the expr, too. This was adding a missing test as pointed out by the stabilization report.
* Expansion of `ui/let-else/let-else-allow-unused.rs` and `ui/let-else/let-else-check.rs` to ensure that non-presence of `#[allow(unused)]` does issue the unused lint. This was adding a missing test case as pointed out by the stabilization report.

Added by 5bd71063b3 (#94208):

* [`ui/let-else/let-else-slicing-error.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-slicing-error.rs), a regression test for #92069, which got fixed without addition of a regression test. This resolves a missing test as pointed out by the stabilization report.

Added by 5374688e1d (#98574):

* [`src/test/ui/async-await/async-await-let-else.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/async-await/async-await-let-else.rs) to test the interaction of async/await with `let else`

Added by 6c529ded86 (#98574):

* [`src/test/ui/let-else/let-else-temporary-lifetime.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-temporary-lifetime.rs) as a (partial) regression test for #98672

Added by 9b56640106 (#99518):

* [`src/test/ui/let-else/let-else-temp-borrowck.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-temporary-lifetime.rs) as a regression test for #93951
* Extension of `src/test/ui/let-else/let-else-temporary-lifetime.rs` to include a partial regression test for #98672 (especially regarding `else` drop order)

Added by baf9a7cb57 (#99518):

* Extension of `src/test/ui/let-else/let-else-temporary-lifetime.rs` to include a partial regression test for #93951, similar to `let-else-temp-borrowck.rs`

Added by 60be2de8b7 (#99518):

* Extension of `src/test/ui/let-else/let-else-temporary-lifetime.rs` to include a program that can now be compiled thanks to borrow checker implications of #99518

Added by 47a7a91c96 (#100132):

* [`src/test/ui/let-else/issue-100103.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/issue-100103.rs), as a regression test for #100103, to ensure that there is no ICE when doing `Err(...)?` inside else blocks.

Added by e3c5bd617d (#100443):

* [`src/test/ui/let-else/let-else-then-diverge.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-then-diverge.rs), to verify that there is no unreachable code error with the current desugaring.

Added by 981852677c (#100443):

* [`src/test/ui/let-else/issue-94176.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/issue-94176.rs), to make sure that a correct span is emitted for a missing trailing expression error. Regression test for #94176.

Added by e182d12a84 (#100434):

* [src/test/ui/unpretty/pretty-let-else.rs](https://github.com/rust-lang/rust/blob/master/src/test/ui/unpretty/pretty-let-else.rs), as a regression test to ensure pretty printing works for `let else` (this bug surfaced in many different ways)

Added by e26285603c (#99954):

* [`src/test/ui/let-else/let-else-temporary-lifetime.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-temporary-lifetime.rs) extended to contain & borrows as well, as this was identified as an earlier issue with the desugaring: https://github.com/rust-lang/rust/issues/98672#issuecomment-1200196921

Added by 2d8460ef43 (#99291):

* [`src/test/ui/let-else/let-else-drop-order.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-drop-order.rs) a matrix based test for various drop order behaviour of `let else`. Especially, it verifies equality of `let` and `let else` drop orders, [resolving](https://github.com/rust-lang/rust/pull/93628#issuecomment-1238498468) a [stabilization blocker](https://github.com/rust-lang/rust/pull/93628#issuecomment-1055738523).

Added by 1b87ce0d40 (#101410):

* Edit to `src/test/ui/let-else/let-else-temporary-lifetime.rs` to add the `-Zvalidate-mir` flag, as a regression test for #99228

Added by af591ebe4d (#101410):

* [`src/test/ui/let-else/issue-99975.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/issue-99975.rs) as a regression test for the ICE #99975.

Added by this PR:

* `ui/let-else/let-else.rs`, a simple run-pass check, similar to `ui/let-else/let-else-run-pass.rs`.

### Things not currently tested

* ~~The `#[allow(...)]` tests check whether allow works, but they don't check whether the non-presence of allow causes a lint to fire.~~ → *test added by e7730dcb7eb29a10ee73f269f4dc6e9d606db0da*
* ~~There is no `#[allow(...)]` test for the expression, as there are tests for the pattern and the else block.~~ → *test added by e7730dcb7eb29a10ee73f269f4dc6e9d606db0da*
* ~~`let-else-brace-before-else.rs` forbids the `let ... = {} else {}` pattern and there is a rustfix to obtain `let ... = ({}) else {}`. I'm not sure whether the `.fixed` files are checked by the tooling that they compile. But if there is no such check, it would be neat to make sure that `let ... = ({}) else {}` compiles.~~ → *test added by e7730dcb7eb29a10ee73f269f4dc6e9d606db0da*
* ~~#92069 got closed as fixed, but no regression test was added. Not sure it's worth to add one.~~ → *test added by 5bd71063b3810d977aa376d1e6dd7cec359330cc*
* ~~consistency between `let else` and `if let` regarding lifetimes and drop order: https://github.com/rust-lang/rust/pull/93628#issuecomment-1055738523~~ → *test added by 2d8460ef43d902f34ba2133fe38f66ee8d2fdafc*

Edit: they are all tested now.

### Possible future work / Refutable destructuring assignments

[RFC 2909](https://rust-lang.github.io/rfcs/2909-destructuring-assignment.html) specifies destructuring assignment, allowing statements like `FooBar { a, b, c } = foo();`.
As it was stabilized, destructuring assignment only allows *irrefutable* patterns, which before the advent of `let else` were the only patterns that `let` supported.
So the combination of `let else` and destructuring assignments gives reason to think about extensions of the destructuring assignments feature that allow refutable patterns, discussed in #93995.

A naive mapping of `let else` to destructuring assignments in the form of `Some(v) = foo() else { ... };` might not be the ideal way. `let else` needs a diverging `else` clause as it introduces new bindings, while assignments have a default behaviour to fall back to if the pattern does not match, in the form of not performing the assignment. Thus, there is no good case to require divergence, or even an `else` clause at all, beyond the need for having *some* introducer syntax so that it is clear to readers that the assignment is not a given (enums and structs look similar). There are better candidates for introducer syntax however than an empty `else {}` clause, like `maybe` which could be added as a keyword on an edition boundary:

```Rust
let mut v = 0;
maybe Some(v) = foo(&v);
maybe Some(v) = foo(&v) else { bar() };
```

Further design discussion is left to an RFC, or the linked issue.
 2022-09-17 15:31:06 +05:30
est31
173eb6f407 Only enable the let_else feature on bootstrap 
On later stages, the feature is already stable.

Result of running:

rg -l "feature.let_else" compiler/ src/librustdoc/ library/ | xargs sed -s -i "s#\\[feature.let_else#\\[cfg_attr\\(bootstrap, feature\\(let_else\\)#"
 2022-09-15 21:06:45 +02:00
Santiago Pastorino
45d8049387 Get rid of 'b lifetime in lower_param_bounds_mut 2022-09-14 17:40:51 -03:00
Santiago Pastorino
861055094c Pass ImplTraitContext as &, there's no need for that to be &mut 2022-09-14 17:39:52 -03:00
Santiago Pastorino
669f2d4550 Revert "Rollup merge of #101496 - spastorino:lower_lifetime_binder_api_changes, r=oli-obk" 
This reverts commit 953a6b3da7, reversing
changes made to b5ffbd32d4.
 2022-09-14 17:26:37 -03:00
bors
fa521a4691 Auto merge of #101688 - cjgillot:verify-hir-parent, r=petrochenkov 
Assert that HIR nodes are not their own parent.

Fixes https://github.com/rust-lang/rust/issues/101505.
Replaces #101513

r? `@petrochenkov` `@nnethercote`
 2022-09-12 00:41:56 +00:00
Camille GILLOT
51f486931f Assert that HIR nodes are not their own parent. 2022-09-11 20:12:51 +02:00
Michael Goulet
ec170bef0d Rebase fallout 2022-09-09 01:31:46 +00:00
Michael Goulet
526511e86b Appease clippy again 2022-09-09 01:31:46 +00:00
Michael Goulet
55df9201fe Tweak feature error, add test 2022-09-09 01:31:46 +00:00
Camille GILLOT
05812df603 Handle generic parameters. 2022-09-09 01:31:46 +00:00
Michael Goulet
cdf78073c5 Deeply check that method signatures match, and allow for nested RPITITs 2022-09-09 01:31:46 +00:00
Michael Goulet
1f03edeabe Bless tests, fix ICE with ImplTraitPlaceholder 2022-09-09 01:31:45 +00:00
Michael Goulet
70775304cd Address nits 2022-09-09 01:31:45 +00:00
Michael Goulet
249ede4195 Address rebase issues, make async fn in trait work 2022-09-09 01:31:45 +00:00
Michael Goulet
5be30f9d79 Make async fn in traits work 2022-09-09 01:31:45 +00:00
Michael Goulet
d34cb98fb0 Lower RPITIT to ImplTraitPlaceholder item 2022-09-09 01:31:44 +00:00
Michael Goulet
1499c089df Rollup merge of #101499 - spastorino:add-lowering-arena, r=oli-obk 
Introduce lowering_arena to avoid creating AST nodes on the fly

`@oli-obk` requested this and other changes as a way of simplifying https://github.com/rust-lang/rust/pull/101345. This is just going to make the diff of https://github.com/rust-lang/rust/pull/101345 smaller.

r? `@oli-obk` `@cjgillot`
 2022-09-08 14:41:08 -07:00