Remove ref_pat_everywhere

This commit is contained in:
Jules Bertholet 2024-05-15 15:11:23 -04:00
parent b21b74b5e6
commit a32fb2f8aa
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GPG Key ID: 32034DAFC38C1BFC
8 changed files with 14 additions and 191 deletions

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@ -181,6 +181,7 @@ declare_features! (
(removed, pushpop_unsafe, "1.2.0", None, None),
(removed, quad_precision_float, "1.0.0", None, None),
(removed, quote, "1.33.0", Some(29601), None),
(removed, ref_pat_everywhere, "1.79.0", Some(123076), Some("superseded by `ref_pat_eat_one_layer_2024")),
(removed, reflect, "1.0.0", Some(27749), None),
/// Allows using the `#[register_attr]` attribute.
(removed, register_attr, "1.65.0", Some(66080),

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@ -571,8 +571,6 @@ declare_features! (
(unstable, raw_ref_op, "1.41.0", Some(64490)),
/// Makes `&` and `&mut` patterns eat only one layer of references in Rust 2024.
(incomplete, ref_pat_eat_one_layer_2024, "1.79.0", Some(123076)),
/// Allows `&` and `&mut` patterns to consume match-ergonomics-inserted references.
(incomplete, ref_pat_everywhere, "1.79.0", Some(123076)),
/// Allows using the `#[register_tool]` attribute.
(unstable, register_tool, "1.41.0", Some(66079)),
/// Allows the `#[repr(i128)]` attribute for enums.

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@ -2125,25 +2125,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
mut expected: Ty<'tcx>,
mut pat_info: PatInfo<'tcx, '_>,
) -> Ty<'tcx> {
// FIXME: repace with `bool` once final decision on 1 vs 2 layers is made
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
enum MatchErgonomicsMode {
EatOneLayer,
EatTwoLayers,
Legacy,
}
let new_match_ergonomics =
pat.span.at_least_rust_2024() && self.tcx.features().ref_pat_eat_one_layer_2024;
let match_ergonomics_mode =
if pat.span.at_least_rust_2024() && self.tcx.features().ref_pat_eat_one_layer_2024 {
MatchErgonomicsMode::EatOneLayer
} else if self.tcx.features().ref_pat_everywhere {
MatchErgonomicsMode::EatTwoLayers
} else {
MatchErgonomicsMode::Legacy
};
let mut inherited_ref_mutbl_match = false;
if match_ergonomics_mode != MatchErgonomicsMode::Legacy {
if new_match_ergonomics {
if pat_mutbl == Mutability::Not {
// Prevent the inner pattern from binding with `ref mut`.
pat_info.max_ref_mutbl = pat_info.max_ref_mutbl.cap_to_weakly_not(
@ -2151,20 +2136,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
);
}
if let ByRef::Yes(inh_mut) = pat_info.binding_mode {
inherited_ref_mutbl_match = pat_mutbl <= inh_mut;
}
if inherited_ref_mutbl_match {
pat_info.binding_mode = ByRef::No;
if match_ergonomics_mode == MatchErgonomicsMode::EatOneLayer {
self.typeck_results.borrow_mut().skipped_ref_pats_mut().insert(pat.hir_id);
self.check_pat(inner, expected, pat_info);
return expected;
}
} else if match_ergonomics_mode == MatchErgonomicsMode::EatOneLayer
&& pat_mutbl == Mutability::Mut
if let ByRef::Yes(inh_mut) = pat_info.binding_mode
&& pat_mutbl <= inh_mut
{
pat_info.binding_mode = ByRef::No;
self.typeck_results.borrow_mut().skipped_ref_pats_mut().insert(pat.hir_id);
self.check_pat(inner, expected, pat_info);
return expected;
} else if pat_mutbl == Mutability::Mut {
// `&mut` patterns pell off `&` references
let (new_expected, new_bm, max_ref_mutbl) = self.peel_off_references(
pat,
@ -2204,33 +2183,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
// the bad interactions of the given hack detailed in (note_1).
debug!("check_pat_ref: expected={:?}", expected);
match *expected.kind() {
ty::Ref(_, r_ty, r_mutbl) if r_mutbl == pat_mutbl => {
if r_mutbl == Mutability::Not
&& match_ergonomics_mode != MatchErgonomicsMode::Legacy
{
ty::Ref(_, r_ty, r_mutbl) if r_mutbl >= pat_mutbl && new_match_ergonomics => {
if r_mutbl == Mutability::Not {
pat_info.max_ref_mutbl = MutblCap::Not;
}
(expected, r_ty)
}
// `&` pattern eats `&mut` reference
ty::Ref(_, r_ty, Mutability::Mut)
if pat_mutbl == Mutability::Not
&& match_ergonomics_mode != MatchErgonomicsMode::Legacy =>
{
(expected, r_ty)
}
_ if inherited_ref_mutbl_match
&& match_ergonomics_mode == MatchErgonomicsMode::EatTwoLayers =>
{
// We already matched against a match-ergonmics inserted reference,
// so we don't need to match against a reference from the original type.
// Save this info for use in lowering later
self.typeck_results.borrow_mut().skipped_ref_pats_mut().insert(pat.hir_id);
(expected, expected)
}
ty::Ref(_, r_ty, r_mutbl) if r_mutbl == pat_mutbl => (expected, r_ty),
_ => {
let inner_ty = self.next_ty_var(inner.span);

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@ -1,14 +0,0 @@
pub fn main() {
if let Some(Some(&x)) = &Some(&Some(0)) {
//~^ ERROR: mismatched types [E0308]
let _: u32 = x;
}
if let Some(&Some(x)) = &Some(Some(0)) {
//~^ ERROR: mismatched types [E0308]
let _: u32 = x;
}
if let Some(Some(&mut x)) = &mut Some(&mut Some(0)) {
//~^ ERROR: mismatched types [E0308]
let _: u32 = x;
}
}

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@ -1,49 +0,0 @@
error[E0308]: mismatched types
--> $DIR/feature-gate-ref_pat_everywhere.rs:2:22
|
LL | if let Some(Some(&x)) = &Some(&Some(0)) {
| ^^ --------------- this expression has type `&Option<&Option<{integer}>>`
| |
| expected integer, found `&_`
|
= note: expected type `{integer}`
found reference `&_`
help: consider removing `&` from the pattern
|
LL | if let Some(Some(x)) = &Some(&Some(0)) {
| ~
error[E0308]: mismatched types
--> $DIR/feature-gate-ref_pat_everywhere.rs:6:17
|
LL | if let Some(&Some(x)) = &Some(Some(0)) {
| ^^^^^^^^ -------------- this expression has type `&Option<Option<{integer}>>`
| |
| expected `Option<{integer}>`, found `&_`
|
= note: expected enum `Option<{integer}>`
found reference `&_`
error[E0308]: mismatched types
--> $DIR/feature-gate-ref_pat_everywhere.rs:10:22
|
LL | if let Some(Some(&mut x)) = &mut Some(&mut Some(0)) {
| ^^^^^^ ----------------------- this expression has type `&mut Option<&mut Option<{integer}>>`
| |
| expected integer, found `&mut _`
|
= note: expected type `{integer}`
found mutable reference `&mut _`
note: to declare a mutable binding use: `mut x`
--> $DIR/feature-gate-ref_pat_everywhere.rs:10:22
|
LL | if let Some(Some(&mut x)) = &mut Some(&mut Some(0)) {
| ^^^^^^
help: consider removing `&mut` from the pattern
|
LL | if let Some(Some(x)) = &mut Some(&mut Some(0)) {
| ~
error: aborting due to 3 previous errors
For more information about this error, try `rustc --explain E0308`.

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@ -1,12 +0,0 @@
#![allow(incomplete_features)]
#![feature(ref_pat_everywhere)]
pub fn main() {
if let Some(&x) = Some(0) {
//~^ ERROR: mismatched types [E0308]
let _: u32 = x;
}
if let Some(&mut x) = Some(&0) {
//~^ ERROR: mismatched types [E0308]
let _: u32 = x;
}
}

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@ -1,38 +0,0 @@
error[E0308]: mismatched types
--> $DIR/ref_pat_everywhere-fail.rs:4:17
|
LL | if let Some(&x) = Some(0) {
| ^^ ------- this expression has type `Option<{integer}>`
| |
| expected integer, found `&_`
|
= note: expected type `{integer}`
found reference `&_`
help: consider removing `&` from the pattern
|
LL | if let Some(x) = Some(0) {
| ~
error[E0308]: mismatched types
--> $DIR/ref_pat_everywhere-fail.rs:8:17
|
LL | if let Some(&mut x) = Some(&0) {
| ^^^^^^ -------- this expression has type `Option<&{integer}>`
| |
| types differ in mutability
|
= note: expected reference `&{integer}`
found mutable reference `&mut _`
note: to declare a mutable binding use: `mut x`
--> $DIR/ref_pat_everywhere-fail.rs:8:17
|
LL | if let Some(&mut x) = Some(&0) {
| ^^^^^^
help: consider removing `&mut` from the pattern
|
LL | if let Some(x) = Some(&0) {
| ~
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0308`.

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@ -1,24 +0,0 @@
//@ run-pass
#![allow(incomplete_features)]
#![feature(ref_pat_everywhere)]
pub fn main() {
if let Some(Some(&x)) = &Some(&Some(0)) {
let _: u32 = x;
}
if let Some(&Some(x)) = &Some(Some(0)) {
let _: u32 = x;
}
if let Some(Some(&mut x)) = &mut Some(&mut Some(0)) {
let _: u32 = x;
}
if let Some(Some(&x)) = &Some(&mut Some(0)) {
let _: u32 = x;
}
if let &Some(x) = &mut Some(0) {
let _: u32 = x;
}
if let Some(&x) = &mut Some(0) {
let _: u32 = x;
}
}