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matthiaskrgrmatthiaskrgr
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Rollup merge of #126354 - compiler-errors:variance, r=lcnr
Use `Variance` glob imported variants everywhere Fully commit to using the globbed variance. Could be convinced the other way, and change this PR to not use the globbed variants anywhere, but I'd rather we do one or the other. r? lcnr
2 parents 8217b41 + 54fa4b0 commit 335e320

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20 files changed

+74
-111
lines changed

20 files changed

+74
-111
lines changed

‎compiler/rustc_borrowck/src/type_check/mod.rs‎

Lines changed: 6 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -328,7 +328,7 @@ impl<'a, 'b, 'tcx> Visitor<'tcx> for TypeVerifier<'a, 'b, 'tcx> {
328328
if let Some(annotation_index) = constant.user_ty {
329329
if let Err(terr) = self.cx.relate_type_and_user_type(
330330
constant.const_.ty(),
331-
ty::Variance::Invariant,
331+
ty::Invariant,
332332
&UserTypeProjection { base: annotation_index, projs: vec![] },
333333
locations,
334334
ConstraintCategory::Boring,
@@ -451,7 +451,7 @@ impl<'a, 'b, 'tcx> Visitor<'tcx> for TypeVerifier<'a, 'b, 'tcx> {
451451

452452
if let Err(terr) = self.cx.relate_type_and_user_type(
453453
ty,
454-
ty::Variance::Invariant,
454+
ty::Invariant,
455455
user_ty,
456456
Locations::All(*span),
457457
ConstraintCategory::TypeAnnotation,
@@ -1095,7 +1095,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
10951095
) -> Result<(), NoSolution> {
10961096
// Use this order of parameters because the sup type is usually the
10971097
// "expected" type in diagnostics.
1098-
self.relate_types(sup, ty::Variance::Contravariant, sub, locations, category)
1098+
self.relate_types(sup, ty::Contravariant, sub, locations, category)
10991099
}
11001100

11011101
#[instrument(skip(self, category), level = "debug")]
@@ -1106,7 +1106,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
11061106
locations: Locations,
11071107
category: ConstraintCategory<'tcx>,
11081108
) -> Result<(), NoSolution> {
1109-
self.relate_types(expected, ty::Variance::Invariant, found, locations, category)
1109+
self.relate_types(expected, ty::Invariant, found, locations, category)
11101110
}
11111111

11121112
#[instrument(skip(self), level = "debug")]
@@ -1146,7 +1146,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
11461146
trace!(?curr_projected_ty);
11471147

11481148
let ty = curr_projected_ty.ty;
1149-
self.relate_types(ty, v.xform(ty::Variance::Contravariant), a, locations, category)?;
1149+
self.relate_types(ty, v.xform(ty::Contravariant), a, locations, category)?;
11501150

11511151
Ok(())
11521152
}
@@ -1248,7 +1248,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
12481248
if let Some(annotation_index) = self.rvalue_user_ty(rv) {
12491249
if let Err(terr) = self.relate_type_and_user_type(
12501250
rv_ty,
1251-
ty::Variance::Invariant,
1251+
ty::Invariant,
12521252
&UserTypeProjection { base: annotation_index, projs: vec![] },
12531253
location.to_locations(),
12541254
ConstraintCategory::Boring,

‎compiler/rustc_borrowck/src/type_check/relate_tys.rs‎

Lines changed: 15 additions & 25 deletions
Original file line numberDiff line numberDiff line change
@@ -50,14 +50,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
5050
locations: Locations,
5151
category: ConstraintCategory<'tcx>,
5252
) -> Result<(), NoSolution> {
53-
NllTypeRelating::new(
54-
self,
55-
locations,
56-
category,
57-
UniverseInfo::other(),
58-
ty::Variance::Invariant,
59-
)
60-
.relate(a, b)?;
53+
NllTypeRelating::new(self, locations, category, UniverseInfo::other(), ty::Invariant)
54+
.relate(a, b)?;
6155
Ok(())
6256
}
6357
}
@@ -106,15 +100,15 @@ impl<'me, 'bccx, 'tcx> NllTypeRelating<'me, 'bccx, 'tcx> {
106100

107101
fn ambient_covariance(&self) -> bool {
108102
match self.ambient_variance {
109-
ty::Variance::Covariant | ty::Variance::Invariant => true,
110-
ty::Variance::Contravariant | ty::Variance::Bivariant => false,
103+
ty::Covariant | ty::Invariant => true,
104+
ty::Contravariant | ty::Bivariant => false,
111105
}
112106
}
113107

114108
fn ambient_contravariance(&self) -> bool {
115109
match self.ambient_variance {
116-
ty::Variance::Contravariant | ty::Variance::Invariant => true,
117-
ty::Variance::Covariant | ty::Variance::Bivariant => false,
110+
ty::Contravariant | ty::Invariant => true,
111+
ty::Covariant | ty::Bivariant => false,
118112
}
119113
}
120114

@@ -336,11 +330,7 @@ impl<'bccx, 'tcx> TypeRelation<TyCtxt<'tcx>> for NllTypeRelating<'_, 'bccx, 'tcx
336330

337331
debug!(?self.ambient_variance);
338332
// In a bivariant context this always succeeds.
339-
let r = if self.ambient_variance == ty::Variance::Bivariant {
340-
Ok(a)
341-
} else {
342-
self.relate(a, b)
343-
};
333+
let r = if self.ambient_variance == ty::Bivariant { Ok(a) } else { self.relate(a, b) };
344334

345335
self.ambient_variance = old_ambient_variance;
346336

@@ -474,7 +464,7 @@ impl<'bccx, 'tcx> TypeRelation<TyCtxt<'tcx>> for NllTypeRelating<'_, 'bccx, 'tcx
474464
}
475465

476466
match self.ambient_variance {
477-
ty::Variance::Covariant => {
467+
ty::Covariant => {
478468
// Covariance, so we want `for<..> A <: for<..> B` --
479469
// therefore we compare any instantiation of A (i.e., A
480470
// instantiated with existentials) against every
@@ -489,7 +479,7 @@ impl<'bccx, 'tcx> TypeRelation<TyCtxt<'tcx>> for NllTypeRelating<'_, 'bccx, 'tcx
489479
})?;
490480
}
491481

492-
ty::Variance::Contravariant => {
482+
ty::Contravariant => {
493483
// Contravariance, so we want `for<..> A :> for<..> B` --
494484
// therefore we compare every instantiation of A (i.e., A
495485
// instantiated with universals) against any
@@ -504,7 +494,7 @@ impl<'bccx, 'tcx> TypeRelation<TyCtxt<'tcx>> for NllTypeRelating<'_, 'bccx, 'tcx
504494
})?;
505495
}
506496

507-
ty::Variance::Invariant => {
497+
ty::Invariant => {
508498
// Invariant, so we want `for<..> A == for<..> B` --
509499
// therefore we want `exists<..> A == for<..> B` and
510500
// `exists<..> B == for<..> A`.
@@ -525,7 +515,7 @@ impl<'bccx, 'tcx> TypeRelation<TyCtxt<'tcx>> for NllTypeRelating<'_, 'bccx, 'tcx
525515
})?;
526516
}
527517

528-
ty::Variance::Bivariant => {}
518+
ty::Bivariant => {}
529519
}
530520

531521
Ok(a)
@@ -584,23 +574,23 @@ impl<'bccx, 'tcx> PredicateEmittingRelation<'tcx> for NllTypeRelating<'_, 'bccx,
584574

585575
fn register_alias_relate_predicate(&mut self, a: Ty<'tcx>, b: Ty<'tcx>) {
586576
self.register_predicates([ty::Binder::dummy(match self.ambient_variance {
587-
ty::Variance::Covariant => ty::PredicateKind::AliasRelate(
577+
ty::Covariant => ty::PredicateKind::AliasRelate(
588578
a.into(),
589579
b.into(),
590580
ty::AliasRelationDirection::Subtype,
591581
),
592582
// a :> b is b <: a
593-
ty::Variance::Contravariant => ty::PredicateKind::AliasRelate(
583+
ty::Contravariant => ty::PredicateKind::AliasRelate(
594584
b.into(),
595585
a.into(),
596586
ty::AliasRelationDirection::Subtype,
597587
),
598-
ty::Variance::Invariant => ty::PredicateKind::AliasRelate(
588+
ty::Invariant => ty::PredicateKind::AliasRelate(
599589
a.into(),
600590
b.into(),
601591
ty::AliasRelationDirection::Equate,
602592
),
603-
ty::Variance::Bivariant => {
593+
ty::Bivariant => {
604594
unreachable!("cannot defer an alias-relate goal with Bivariant variance (yet?)")
605595
}
606596
})]);

‎compiler/rustc_infer/src/infer/at.rs‎

Lines changed: 4 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -212,16 +212,16 @@ impl<'a, 'tcx> At<'a, 'tcx> {
212212
T: ToTrace<'tcx>,
213213
{
214214
match variance {
215-
ty::Variance::Covariant => self.sub(define_opaque_types, expected, actual),
216-
ty::Variance::Invariant => self.eq(define_opaque_types, expected, actual),
217-
ty::Variance::Contravariant => self.sup(define_opaque_types, expected, actual),
215+
ty::Covariant => self.sub(define_opaque_types, expected, actual),
216+
ty::Invariant => self.eq(define_opaque_types, expected, actual),
217+
ty::Contravariant => self.sup(define_opaque_types, expected, actual),
218218

219219
// We could make this make sense but it's not readily
220220
// exposed and I don't feel like dealing with it. Note
221221
// that bivariance in general does a bit more than just
222222
// *nothing*, it checks that the types are the same
223223
// "modulo variance" basically.
224-
ty::Variance::Bivariant => panic!("Bivariant given to `relate()`"),
224+
ty::Bivariant => panic!("Bivariant given to `relate()`"),
225225
}
226226
}
227227

‎compiler/rustc_infer/src/infer/opaque_types/mod.rs‎

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -345,7 +345,7 @@ impl<'tcx> InferCtxt<'tcx> {
345345
.args
346346
.iter()
347347
.enumerate()
348-
.filter(|(i, _)| variances[*i] == ty::Variance::Invariant)
348+
.filter(|(i, _)| variances[*i] == ty::Invariant)
349349
.filter_map(|(_, arg)| match arg.unpack() {
350350
GenericArgKind::Lifetime(r) => Some(r),
351351
GenericArgKind::Type(_) | GenericArgKind::Const(_) => None,
@@ -441,7 +441,7 @@ where
441441
let variances = self.tcx.variances_of(*def_id);
442442

443443
for (v, s) in std::iter::zip(variances, args.iter()) {
444-
if *v != ty::Variance::Bivariant {
444+
if *v != ty::Bivariant {
445445
s.visit_with(self);
446446
}
447447
}

‎compiler/rustc_infer/src/infer/outlives/for_liveness.rs‎

Lines changed: 1 addition & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -102,9 +102,7 @@ where
102102
};
103103

104104
for (idx, s) in args.iter().enumerate() {
105-
if variances.map(|variances| variances[idx])
106-
!= Some(ty::Variance::Bivariant)
107-
{
105+
if variances.map(|variances| variances[idx]) != Some(ty::Bivariant) {
108106
s.visit_with(self);
109107
}
110108
}

‎compiler/rustc_infer/src/infer/relate/generalize.rs‎

Lines changed: 9 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -83,16 +83,16 @@ impl<'tcx> InferCtxt<'tcx> {
8383
// mention `?0`.
8484
if self.next_trait_solver() {
8585
let (lhs, rhs, direction) = match instantiation_variance {
86-
ty::Variance::Invariant => {
86+
ty::Invariant => {
8787
(generalized_ty.into(), source_ty.into(), AliasRelationDirection::Equate)
8888
}
89-
ty::Variance::Covariant => {
89+
ty::Covariant => {
9090
(generalized_ty.into(), source_ty.into(), AliasRelationDirection::Subtype)
9191
}
92-
ty::Variance::Contravariant => {
92+
ty::Contravariant => {
9393
(source_ty.into(), generalized_ty.into(), AliasRelationDirection::Subtype)
9494
}
95-
ty::Variance::Bivariant => unreachable!("bivariant generalization"),
95+
ty::Bivariant => unreachable!("bivariant generalization"),
9696
};
9797

9898
relation.register_predicates([ty::PredicateKind::AliasRelate(lhs, rhs, direction)]);
@@ -192,7 +192,7 @@ impl<'tcx> InferCtxt<'tcx> {
192192
relation.span(),
193193
relation.structurally_relate_aliases(),
194194
target_vid,
195-
ty::Variance::Invariant,
195+
ty::Invariant,
196196
source_ct,
197197
)?;
198198

@@ -210,14 +210,14 @@ impl<'tcx> InferCtxt<'tcx> {
210210
// generalized const and the source.
211211
if target_is_expected {
212212
relation.relate_with_variance(
213-
ty::Variance::Invariant,
213+
ty::Invariant,
214214
ty::VarianceDiagInfo::default(),
215215
generalized_ct,
216216
source_ct,
217217
)?;
218218
} else {
219219
relation.relate_with_variance(
220-
ty::Variance::Invariant,
220+
ty::Invariant,
221221
ty::VarianceDiagInfo::default(),
222222
source_ct,
223223
generalized_ct,
@@ -411,7 +411,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Generalizer<'_, 'tcx> {
411411
a_arg: ty::GenericArgsRef<'tcx>,
412412
b_arg: ty::GenericArgsRef<'tcx>,
413413
) -> RelateResult<'tcx, ty::GenericArgsRef<'tcx>> {
414-
if self.ambient_variance == ty::Variance::Invariant {
414+
if self.ambient_variance == ty::Invariant {
415415
// Avoid fetching the variance if we are in an invariant
416416
// context; no need, and it can induce dependency cycles
417417
// (e.g., #41849).
@@ -667,7 +667,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Generalizer<'_, 'tcx> {
667667
// structural.
668668
ty::ConstKind::Unevaluated(ty::UnevaluatedConst { def, args }) => {
669669
let args = self.relate_with_variance(
670-
ty::Variance::Invariant,
670+
ty::Invariant,
671671
ty::VarianceDiagInfo::default(),
672672
args,
673673
args,

‎compiler/rustc_infer/src/infer/relate/glb.rs‎

Lines changed: 1 addition & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -94,12 +94,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Glb<'_, '_, 'tcx> {
9494
// When higher-ranked types are involved, computing the GLB is
9595
// very challenging, switch to invariance. This is obviously
9696
// overly conservative but works ok in practice.
97-
self.relate_with_variance(
98-
ty::Variance::Invariant,
99-
ty::VarianceDiagInfo::default(),
100-
a,
101-
b,
102-
)?;
97+
self.relate_with_variance(ty::Invariant, ty::VarianceDiagInfo::default(), a, b)?;
10398
Ok(a)
10499
} else {
105100
Ok(ty::Binder::dummy(self.relate(a.skip_binder(), b.skip_binder())?))

‎compiler/rustc_infer/src/infer/relate/lub.rs‎

Lines changed: 1 addition & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -94,12 +94,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Lub<'_, '_, 'tcx> {
9494
// When higher-ranked types are involved, computing the LUB is
9595
// very challenging, switch to invariance. This is obviously
9696
// overly conservative but works ok in practice.
97-
self.relate_with_variance(
98-
ty::Variance::Invariant,
99-
ty::VarianceDiagInfo::default(),
100-
a,
101-
b,
102-
)?;
97+
self.relate_with_variance(ty::Invariant, ty::VarianceDiagInfo::default(), a, b)?;
10398
Ok(a)
10499
} else {
105100
Ok(ty::Binder::dummy(self.relate(a.skip_binder(), b.skip_binder())?))

‎compiler/rustc_infer/src/infer/relate/type_relating.rs‎

Lines changed: 5 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -42,7 +42,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for TypeRelating<'_, '_, 'tcx> {
4242
a_arg: ty::GenericArgsRef<'tcx>,
4343
b_arg: ty::GenericArgsRef<'tcx>,
4444
) -> RelateResult<'tcx, ty::GenericArgsRef<'tcx>> {
45-
if self.ambient_variance == ty::Variance::Invariant {
45+
if self.ambient_variance == ty::Invariant {
4646
// Avoid fetching the variance if we are in an invariant
4747
// context; no need, and it can induce dependency cycles
4848
// (e.g., #41849).
@@ -325,23 +325,23 @@ impl<'tcx> PredicateEmittingRelation<'tcx> for TypeRelating<'_, '_, 'tcx> {
325325

326326
fn register_alias_relate_predicate(&mut self, a: Ty<'tcx>, b: Ty<'tcx>) {
327327
self.register_predicates([ty::Binder::dummy(match self.ambient_variance {
328-
ty::Variance::Covariant => ty::PredicateKind::AliasRelate(
328+
ty::Covariant => ty::PredicateKind::AliasRelate(
329329
a.into(),
330330
b.into(),
331331
ty::AliasRelationDirection::Subtype,
332332
),
333333
// a :> b is b <: a
334-
ty::Variance::Contravariant => ty::PredicateKind::AliasRelate(
334+
ty::Contravariant => ty::PredicateKind::AliasRelate(
335335
b.into(),
336336
a.into(),
337337
ty::AliasRelationDirection::Subtype,
338338
),
339-
ty::Variance::Invariant => ty::PredicateKind::AliasRelate(
339+
ty::Invariant => ty::PredicateKind::AliasRelate(
340340
a.into(),
341341
b.into(),
342342
ty::AliasRelationDirection::Equate,
343343
),
344-
ty::Variance::Bivariant => {
344+
ty::Bivariant => {
345345
unreachable!("Expected bivariance to be handled in relate_with_variance")
346346
}
347347
})]);

‎compiler/rustc_middle/src/ty/mod.rs‎

Lines changed: 0 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -16,7 +16,6 @@ pub use self::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeV
1616
pub use self::AssocItemContainer::*;
1717
pub use self::BorrowKind::*;
1818
pub use self::IntVarValue::*;
19-
pub use self::Variance::*;
2019
use crate::error::{OpaqueHiddenTypeMismatch, TypeMismatchReason};
2120
use crate::metadata::ModChild;
2221
use crate::middle::privacy::EffectiveVisibilities;

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