Consider comments and bare delimiters the same as an "empty line" for purposes of hiding rendered code output of long multispans. This results in more aggressive shortening of rendered output without losing too much context, specially in `*.stderr` tests that have "hidden" comments.
Point at types that need to be marked with `#[derive(PartialEq)]`.
We use a visitor to look at a type that isn't structural, looking for all ADTs that don't derive `PartialEq`. These can either be manual `impl PartialEq`s or no `impl` at all, so we differentiate between those two cases to provide more context to the user. We also only point at types and impls from the local crate, otherwise show only a note.
```
error: constant of non-structural type `&[B]` in a pattern
--> $DIR/issue-61188-match-slice-forbidden-without-eq.rs:15:9
|
LL | struct B(i32);
| -------- must be annotated with `#[derive(PartialEq)]` to be usable in patterns
LL |
LL | const A: &[B] = &[];
| ------------- constant defined here
...
LL | A => (),
| ^ constant of non-structural type
|
= note: see https://doc.rust-lang.org/stable/std/marker/trait.StructuralPartialEq.html for details
```
```
error: trait object `dyn Send` cannot be used in patterns
--> $DIR/issue-70972-dyn-trait.rs:6:9
|
LL | const F: &'static dyn Send = &7u32;
| -------------------------- constant defined here
...
LL | F => panic!(),
| ^ trait object can't be used in patterns
```
- Add primary span labels.
- Point at const generic parameter used as pattern.
- Point at statics used as pattern.
- Point at let bindings used in const pattern.
Centralize emitting an error in `const_to_pat` so that all errors from that evaluating a `const` in a pattern can add addditional information. With this, now point at the `const` item's definition:
```
error[E0158]: constant pattern depends on a generic parameter
--> $DIR/associated-const-type-parameter-pattern.rs:20:9
|
LL | pub trait Foo {
| -------------
LL | const X: EFoo;
| ------------- constant defined here
...
LL | A::X => println!("A::X"),
| ^^^^
```
```
error[E0004]: non-exhaustive patterns: `i32::MIN..=3_i32` and `5_i32..=i32::MAX` not covered
--> $DIR/intended-binding-pattern-is-const.rs:2:11
|
LL | match 1 {
| ^ patterns `i32::MIN..=3_i32` and `5_i32..=i32::MAX` not covered
LL | x => {}
| - this pattern doesn't introduce a new catch-all binding, but rather pattern matches against the value of constant `x`
|
= note: the matched value is of type `i32`
note: constant `x` defined here
--> $DIR/intended-binding-pattern-is-const.rs:7:5
|
LL | const x: i32 = 4;
| ^^^^^^^^^^^^
help: if you meant to introduce a binding, use a different name
|
LL | x_var => {}
| ++++
help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern, a match arm with multiple or-patterns as shown, or multiple match arms
|
LL | x => {}, i32::MIN..=3_i32 | 5_i32..=i32::MAX => todo!()
| ++++++++++++++++++++++++++++++++++++++++++++++++
```
Under gate `ref_pat_eat_one_layer_2024_structural`.
Enabling `ref_pat_eat_one_layer_2024` at the same time allows the union
of what the individual gates allow.
This section of code depends on `rustc_apfloat` rather than our internal
types, so this is one potential ICE that we should be able to melt now.
This also fixes some missing range and match handling in `rustc_middle`.
Match ergonomics 2024: align implementation with RFC
- Remove eat-two-layers (`ref_pat_everywhere`)
- Consolidate `mut_preserve_binding_mode_2024` into `ref_pat_eat_one_layer_2024`
- `&mut` no longer peels off `&`
- Apply "no `ref mut` behind `&`" rule on all editions with `ref_pat_eat_one_layer_2024`
- Require `mut_ref` feature gate for all mutable by-reference bindings
r? ``@Nadrieril``
cc https://github.com/rust-lang/rust/issues/123076
``@rustbot`` label A-edition-2024 A-patterns
Match ergonomics: implement "`&`pat everywhere"
Implements the eat-two-layers (feature gate `and_pat_everywhere`, all editions) ~and the eat-one-layer (feature gate `and_eat_one_layer_2024`, edition 2024 only, takes priority on that edition when both feature gates are active)~ (EDIT: will be done in later PR) semantics.
cc #123076
r? ``@Nadrieril``
``@rustbot`` label A-patterns A-edition-2024
The original proposal allows reference patterns
with "compatible" mutability, however it's not clear
what that means so for now we require an exact match.
I don't know the type system code well, so if something
seems to not make sense it's probably because I made a
mistake
Experimental feature postfix match
This has a basic experimental implementation for the RFC postfix match (rust-lang/rfcs#3295, #121618). [Liaison is](https://rust-lang.zulipchat.com/#narrow/stream/213817-t-lang/topic/Postfix.20Match.20Liaison/near/423301844) ```@scottmcm``` with the lang team's [experimental feature gate process](https://github.com/rust-lang/lang-team/blob/master/src/how_to/experiment.md).
This feature has had an RFC for a while, and there has been discussion on it for a while. It would probably be valuable to see it out in the field rather than continue discussing it. This feature also allows to see how popular postfix expressions like this are for the postfix macros RFC, as those will take more time to implement.
It is entirely implemented in the parser, so it should be relatively easy to remove if needed.
This PR is split in to 5 commits to ease review.
1. The implementation of the feature & gating.
2. Add a MatchKind field, fix uses, fix pretty.
3. Basic rustfmt impl, as rustfmt crashes upon seeing this syntax without a fix.
4. Add new MatchSource to HIR for Clippy & other HIR consumers
make matching on NaN a hard error, and remove the rest of illegal_floating_point_literal_pattern
These arms would never be hit anyway, so the pattern makes little sense. We have had a future-compat lint against float matches in general for a *long* time, so I hope we can get away with immediately making this a hard error.
This is part of implementing https://github.com/rust-lang/rfcs/pull/3535.
Closes https://github.com/rust-lang/rust/issues/41620 by removing the lint.
https://github.com/rust-lang/reference/pull/1456 updates the reference to match.
