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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
This commit is contained in:
Matthias Krüger 2024-06-15 10:56:40 +02:00 committed by GitHub
commit 335e320baa
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GPG key ID: B5690EEEBB952194
20 changed files with 74 additions and 111 deletions

View file

@ -328,7 +328,7 @@ impl<'a, 'b, 'tcx> Visitor<'tcx> for TypeVerifier<'a, 'b, 'tcx> {
if let Some(annotation_index) = constant.user_ty {
if let Err(terr) = self.cx.relate_type_and_user_type(
constant.const_.ty(),
ty::Variance::Invariant,
ty::Invariant,
&UserTypeProjection { base: annotation_index, projs: vec![] },
locations,
ConstraintCategory::Boring,
@ -451,7 +451,7 @@ impl<'a, 'b, 'tcx> Visitor<'tcx> for TypeVerifier<'a, 'b, 'tcx> {
if let Err(terr) = self.cx.relate_type_and_user_type(
ty,
ty::Variance::Invariant,
ty::Invariant,
user_ty,
Locations::All(*span),
ConstraintCategory::TypeAnnotation,
@ -1095,7 +1095,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
) -> Result<(), NoSolution> {
// Use this order of parameters because the sup type is usually the
// "expected" type in diagnostics.
self.relate_types(sup, ty::Variance::Contravariant, sub, locations, category)
self.relate_types(sup, ty::Contravariant, sub, locations, category)
}
#[instrument(skip(self, category), level = "debug")]
@ -1106,7 +1106,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
locations: Locations,
category: ConstraintCategory<'tcx>,
) -> Result<(), NoSolution> {
self.relate_types(expected, ty::Variance::Invariant, found, locations, category)
self.relate_types(expected, ty::Invariant, found, locations, category)
}
#[instrument(skip(self), level = "debug")]
@ -1146,7 +1146,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
trace!(?curr_projected_ty);
let ty = curr_projected_ty.ty;
self.relate_types(ty, v.xform(ty::Variance::Contravariant), a, locations, category)?;
self.relate_types(ty, v.xform(ty::Contravariant), a, locations, category)?;
Ok(())
}
@ -1248,7 +1248,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
if let Some(annotation_index) = self.rvalue_user_ty(rv) {
if let Err(terr) = self.relate_type_and_user_type(
rv_ty,
ty::Variance::Invariant,
ty::Invariant,
&UserTypeProjection { base: annotation_index, projs: vec![] },
location.to_locations(),
ConstraintCategory::Boring,

View file

@ -50,14 +50,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
locations: Locations,
category: ConstraintCategory<'tcx>,
) -> Result<(), NoSolution> {
NllTypeRelating::new(
self,
locations,
category,
UniverseInfo::other(),
ty::Variance::Invariant,
)
.relate(a, b)?;
NllTypeRelating::new(self, locations, category, UniverseInfo::other(), ty::Invariant)
.relate(a, b)?;
Ok(())
}
}
@ -106,15 +100,15 @@ impl<'me, 'bccx, 'tcx> NllTypeRelating<'me, 'bccx, 'tcx> {
fn ambient_covariance(&self) -> bool {
match self.ambient_variance {
ty::Variance::Covariant | ty::Variance::Invariant => true,
ty::Variance::Contravariant | ty::Variance::Bivariant => false,
ty::Covariant | ty::Invariant => true,
ty::Contravariant | ty::Bivariant => false,
}
}
fn ambient_contravariance(&self) -> bool {
match self.ambient_variance {
ty::Variance::Contravariant | ty::Variance::Invariant => true,
ty::Variance::Covariant | ty::Variance::Bivariant => false,
ty::Contravariant | ty::Invariant => true,
ty::Covariant | ty::Bivariant => false,
}
}
@ -336,11 +330,7 @@ impl<'bccx, 'tcx> TypeRelation<TyCtxt<'tcx>> for NllTypeRelating<'_, 'bccx, 'tcx
debug!(?self.ambient_variance);
// In a bivariant context this always succeeds.
let r = if self.ambient_variance == ty::Variance::Bivariant {
Ok(a)
} else {
self.relate(a, b)
};
let r = if self.ambient_variance == ty::Bivariant { Ok(a) } else { self.relate(a, b) };
self.ambient_variance = old_ambient_variance;
@ -474,7 +464,7 @@ impl<'bccx, 'tcx> TypeRelation<TyCtxt<'tcx>> for NllTypeRelating<'_, 'bccx, 'tcx
}
match self.ambient_variance {
ty::Variance::Covariant => {
ty::Covariant => {
// Covariance, so we want `for<..> A <: for<..> B` --
// therefore we compare any instantiation of A (i.e., A
// instantiated with existentials) against every
@ -489,7 +479,7 @@ impl<'bccx, 'tcx> TypeRelation<TyCtxt<'tcx>> for NllTypeRelating<'_, 'bccx, 'tcx
})?;
}
ty::Variance::Contravariant => {
ty::Contravariant => {
// Contravariance, so we want `for<..> A :> for<..> B` --
// therefore we compare every instantiation of A (i.e., A
// instantiated with universals) against any
@ -504,7 +494,7 @@ impl<'bccx, 'tcx> TypeRelation<TyCtxt<'tcx>> for NllTypeRelating<'_, 'bccx, 'tcx
})?;
}
ty::Variance::Invariant => {
ty::Invariant => {
// Invariant, so we want `for<..> A == for<..> B` --
// therefore we want `exists<..> A == for<..> B` and
// `exists<..> B == for<..> A`.
@ -525,7 +515,7 @@ impl<'bccx, 'tcx> TypeRelation<TyCtxt<'tcx>> for NllTypeRelating<'_, 'bccx, 'tcx
})?;
}
ty::Variance::Bivariant => {}
ty::Bivariant => {}
}
Ok(a)
@ -584,23 +574,23 @@ impl<'bccx, 'tcx> PredicateEmittingRelation<'tcx> for NllTypeRelating<'_, 'bccx,
fn register_alias_relate_predicate(&mut self, a: Ty<'tcx>, b: Ty<'tcx>) {
self.register_predicates([ty::Binder::dummy(match self.ambient_variance {
ty::Variance::Covariant => ty::PredicateKind::AliasRelate(
ty::Covariant => ty::PredicateKind::AliasRelate(
a.into(),
b.into(),
ty::AliasRelationDirection::Subtype,
),
// a :> b is b <: a
ty::Variance::Contravariant => ty::PredicateKind::AliasRelate(
ty::Contravariant => ty::PredicateKind::AliasRelate(
b.into(),
a.into(),
ty::AliasRelationDirection::Subtype,
),
ty::Variance::Invariant => ty::PredicateKind::AliasRelate(
ty::Invariant => ty::PredicateKind::AliasRelate(
a.into(),
b.into(),
ty::AliasRelationDirection::Equate,
),
ty::Variance::Bivariant => {
ty::Bivariant => {
unreachable!("cannot defer an alias-relate goal with Bivariant variance (yet?)")
}
})]);

View file

@ -212,16 +212,16 @@ impl<'a, 'tcx> At<'a, 'tcx> {
T: ToTrace<'tcx>,
{
match variance {
ty::Variance::Covariant => self.sub(define_opaque_types, expected, actual),
ty::Variance::Invariant => self.eq(define_opaque_types, expected, actual),
ty::Variance::Contravariant => self.sup(define_opaque_types, expected, actual),
ty::Covariant => self.sub(define_opaque_types, expected, actual),
ty::Invariant => self.eq(define_opaque_types, expected, actual),
ty::Contravariant => self.sup(define_opaque_types, expected, actual),
// We could make this make sense but it's not readily
// exposed and I don't feel like dealing with it. Note
// that bivariance in general does a bit more than just
// *nothing*, it checks that the types are the same
// "modulo variance" basically.
ty::Variance::Bivariant => panic!("Bivariant given to `relate()`"),
ty::Bivariant => panic!("Bivariant given to `relate()`"),
}
}

View file

@ -345,7 +345,7 @@ impl<'tcx> InferCtxt<'tcx> {
.args
.iter()
.enumerate()
.filter(|(i, _)| variances[*i] == ty::Variance::Invariant)
.filter(|(i, _)| variances[*i] == ty::Invariant)
.filter_map(|(_, arg)| match arg.unpack() {
GenericArgKind::Lifetime(r) => Some(r),
GenericArgKind::Type(_) | GenericArgKind::Const(_) => None,
@ -441,7 +441,7 @@ where
let variances = self.tcx.variances_of(*def_id);
for (v, s) in std::iter::zip(variances, args.iter()) {
if *v != ty::Variance::Bivariant {
if *v != ty::Bivariant {
s.visit_with(self);
}
}

View file

@ -102,9 +102,7 @@ where
};
for (idx, s) in args.iter().enumerate() {
if variances.map(|variances| variances[idx])
!= Some(ty::Variance::Bivariant)
{
if variances.map(|variances| variances[idx]) != Some(ty::Bivariant) {
s.visit_with(self);
}
}

View file

@ -83,16 +83,16 @@ impl<'tcx> InferCtxt<'tcx> {
// mention `?0`.
if self.next_trait_solver() {
let (lhs, rhs, direction) = match instantiation_variance {
ty::Variance::Invariant => {
ty::Invariant => {
(generalized_ty.into(), source_ty.into(), AliasRelationDirection::Equate)
}
ty::Variance::Covariant => {
ty::Covariant => {
(generalized_ty.into(), source_ty.into(), AliasRelationDirection::Subtype)
}
ty::Variance::Contravariant => {
ty::Contravariant => {
(source_ty.into(), generalized_ty.into(), AliasRelationDirection::Subtype)
}
ty::Variance::Bivariant => unreachable!("bivariant generalization"),
ty::Bivariant => unreachable!("bivariant generalization"),
};
relation.register_predicates([ty::PredicateKind::AliasRelate(lhs, rhs, direction)]);
@ -192,7 +192,7 @@ impl<'tcx> InferCtxt<'tcx> {
relation.span(),
relation.structurally_relate_aliases(),
target_vid,
ty::Variance::Invariant,
ty::Invariant,
source_ct,
)?;
@ -210,14 +210,14 @@ impl<'tcx> InferCtxt<'tcx> {
// generalized const and the source.
if target_is_expected {
relation.relate_with_variance(
ty::Variance::Invariant,
ty::Invariant,
ty::VarianceDiagInfo::default(),
generalized_ct,
source_ct,
)?;
} else {
relation.relate_with_variance(
ty::Variance::Invariant,
ty::Invariant,
ty::VarianceDiagInfo::default(),
source_ct,
generalized_ct,
@ -411,7 +411,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Generalizer<'_, 'tcx> {
a_arg: ty::GenericArgsRef<'tcx>,
b_arg: ty::GenericArgsRef<'tcx>,
) -> RelateResult<'tcx, ty::GenericArgsRef<'tcx>> {
if self.ambient_variance == ty::Variance::Invariant {
if self.ambient_variance == ty::Invariant {
// Avoid fetching the variance if we are in an invariant
// context; no need, and it can induce dependency cycles
// (e.g., #41849).
@ -667,7 +667,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Generalizer<'_, 'tcx> {
// structural.
ty::ConstKind::Unevaluated(ty::UnevaluatedConst { def, args }) => {
let args = self.relate_with_variance(
ty::Variance::Invariant,
ty::Invariant,
ty::VarianceDiagInfo::default(),
args,
args,

View file

@ -94,12 +94,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Glb<'_, '_, 'tcx> {
// When higher-ranked types are involved, computing the GLB is
// very challenging, switch to invariance. This is obviously
// overly conservative but works ok in practice.
self.relate_with_variance(
ty::Variance::Invariant,
ty::VarianceDiagInfo::default(),
a,
b,
)?;
self.relate_with_variance(ty::Invariant, ty::VarianceDiagInfo::default(), a, b)?;
Ok(a)
} else {
Ok(ty::Binder::dummy(self.relate(a.skip_binder(), b.skip_binder())?))

View file

@ -94,12 +94,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Lub<'_, '_, 'tcx> {
// When higher-ranked types are involved, computing the LUB is
// very challenging, switch to invariance. This is obviously
// overly conservative but works ok in practice.
self.relate_with_variance(
ty::Variance::Invariant,
ty::VarianceDiagInfo::default(),
a,
b,
)?;
self.relate_with_variance(ty::Invariant, ty::VarianceDiagInfo::default(), a, b)?;
Ok(a)
} else {
Ok(ty::Binder::dummy(self.relate(a.skip_binder(), b.skip_binder())?))

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@ -42,7 +42,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for TypeRelating<'_, '_, 'tcx> {
a_arg: ty::GenericArgsRef<'tcx>,
b_arg: ty::GenericArgsRef<'tcx>,
) -> RelateResult<'tcx, ty::GenericArgsRef<'tcx>> {
if self.ambient_variance == ty::Variance::Invariant {
if self.ambient_variance == ty::Invariant {
// Avoid fetching the variance if we are in an invariant
// context; no need, and it can induce dependency cycles
// (e.g., #41849).
@ -325,23 +325,23 @@ impl<'tcx> PredicateEmittingRelation<'tcx> for TypeRelating<'_, '_, 'tcx> {
fn register_alias_relate_predicate(&mut self, a: Ty<'tcx>, b: Ty<'tcx>) {
self.register_predicates([ty::Binder::dummy(match self.ambient_variance {
ty::Variance::Covariant => ty::PredicateKind::AliasRelate(
ty::Covariant => ty::PredicateKind::AliasRelate(
a.into(),
b.into(),
ty::AliasRelationDirection::Subtype,
),
// a :> b is b <: a
ty::Variance::Contravariant => ty::PredicateKind::AliasRelate(
ty::Contravariant => ty::PredicateKind::AliasRelate(
b.into(),
a.into(),
ty::AliasRelationDirection::Subtype,
),
ty::Variance::Invariant => ty::PredicateKind::AliasRelate(
ty::Invariant => ty::PredicateKind::AliasRelate(
a.into(),
b.into(),
ty::AliasRelationDirection::Equate,
),
ty::Variance::Bivariant => {
ty::Bivariant => {
unreachable!("Expected bivariance to be handled in relate_with_variance")
}
})]);

View file

@ -16,7 +16,6 @@ pub use self::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeV
pub use self::AssocItemContainer::*;
pub use self::BorrowKind::*;
pub use self::IntVarValue::*;
pub use self::Variance::*;
use crate::error::{OpaqueHiddenTypeMismatch, TypeMismatchReason};
use crate::metadata::ModChild;
use crate::middle::privacy::EffectiveVisibilities;

View file

@ -142,7 +142,7 @@ impl<'tcx> Value<TyCtxt<'tcx>> for &[ty::Variance] {
&& let Some(def_id) = frame.query.def_id
{
let n = tcx.generics_of(def_id).own_params.len();
vec![ty::Variance::Bivariant; n].leak()
vec![ty::Bivariant; n].leak()
} else {
span_bug!(
cycle_error.usage.as_ref().unwrap().0,

View file

@ -699,7 +699,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
// exactly `T` (i.e., with invariance). The variance field, in
// contrast, is intended to be used to relate `T` to the type of
// `<expr>`.
ty::Variance::Invariant,
ty::Invariant,
),
},
);

View file

@ -92,7 +92,7 @@ impl<'tcx> Cx<'tcx> {
kind: PatKind::AscribeUserType {
ascription: Ascription {
annotation,
variance: ty::Variance::Covariant,
variance: ty::Covariant,
},
subpattern: pattern,
},

View file

@ -525,7 +525,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
};
kind = PatKind::AscribeUserType {
subpattern: Box::new(Pat { span, ty, kind }),
ascription: Ascription { annotation, variance: ty::Variance::Covariant },
ascription: Ascription { annotation, variance: ty::Covariant },
};
}
@ -612,7 +612,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
annotation,
// Note that use `Contravariant` here. See the
// `variance` field documentation for details.
variance: ty::Variance::Contravariant,
variance: ty::Contravariant,
},
},
ty: const_.ty(),

View file

@ -225,13 +225,8 @@ impl<'tcx> Inliner<'tcx> {
// Normally, this shouldn't be required, but trait normalization failure can create a
// validation ICE.
let output_type = callee_body.return_ty();
if !util::relate_types(
self.tcx,
self.param_env,
ty::Variance::Covariant,
output_type,
destination_ty,
) {
if !util::relate_types(self.tcx, self.param_env, ty::Covariant, output_type, destination_ty)
{
trace!(?output_type, ?destination_ty);
return Err("failed to normalize return type");
}
@ -261,13 +256,8 @@ impl<'tcx> Inliner<'tcx> {
self_arg_ty.into_iter().chain(arg_tuple_tys).zip(callee_body.args_iter())
{
let input_type = callee_body.local_decls[input].ty;
if !util::relate_types(
self.tcx,
self.param_env,
ty::Variance::Covariant,
input_type,
arg_ty,
) {
if !util::relate_types(self.tcx, self.param_env, ty::Covariant, input_type, arg_ty)
{
trace!(?arg_ty, ?input_type);
return Err("failed to normalize tuple argument type");
}
@ -276,13 +266,8 @@ impl<'tcx> Inliner<'tcx> {
for (arg, input) in args.iter().zip(callee_body.args_iter()) {
let input_type = callee_body.local_decls[input].ty;
let arg_ty = arg.node.ty(&caller_body.local_decls, self.tcx);
if !util::relate_types(
self.tcx,
self.param_env,
ty::Variance::Covariant,
input_type,
arg_ty,
) {
if !util::relate_types(self.tcx, self.param_env, ty::Covariant, input_type, arg_ty)
{
trace!(?arg_ty, ?input_type);
return Err("failed to normalize argument type");
}

View file

@ -866,10 +866,10 @@ impl<'tcx> Stable<'tcx> for ty::Variance {
type T = stable_mir::mir::Variance;
fn stable(&self, _: &mut Tables<'_>) -> Self::T {
match self {
ty::Variance::Bivariant => stable_mir::mir::Variance::Bivariant,
ty::Variance::Contravariant => stable_mir::mir::Variance::Contravariant,
ty::Variance::Covariant => stable_mir::mir::Variance::Covariant,
ty::Variance::Invariant => stable_mir::mir::Variance::Invariant,
ty::Bivariant => stable_mir::mir::Variance::Bivariant,
ty::Contravariant => stable_mir::mir::Variance::Contravariant,
ty::Covariant => stable_mir::mir::Variance::Covariant,
ty::Invariant => stable_mir::mir::Variance::Invariant,
}
}
}

View file

@ -61,8 +61,8 @@ impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
trace!(?lhs, ?rhs);
let variance = match direction {
ty::AliasRelationDirection::Equate => ty::Variance::Invariant,
ty::AliasRelationDirection::Subtype => ty::Variance::Covariant,
ty::AliasRelationDirection::Equate => ty::Invariant,
ty::AliasRelationDirection::Subtype => ty::Covariant,
};
match (lhs.to_alias_term(), rhs.to_alias_term()) {
(None, None) => {
@ -78,7 +78,7 @@ impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
self.relate_rigid_alias_non_alias(
param_env,
alias,
variance.xform(ty::Variance::Contravariant),
variance.xform(ty::Contravariant),
lhs,
)?;
self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)

View file

@ -40,7 +40,7 @@ impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
Ok(res) => Ok(res),
Err(NoSolution) => {
let Goal { param_env, predicate: NormalizesTo { alias, term } } = goal;
self.relate_rigid_alias_non_alias(param_env, alias, ty::Variance::Invariant, term)?;
self.relate_rigid_alias_non_alias(param_env, alias, ty::Invariant, term)?;
self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
}
}

View file

@ -74,6 +74,7 @@ pub use DynKind::*;
pub use InferTy::*;
pub use RegionKind::*;
pub use TyKind::*;
pub use Variance::*;
rustc_index::newtype_index! {
/// A [De Bruijn index][dbi] is a standard means of representing

View file

@ -128,7 +128,7 @@ pub fn relate_args_invariantly<I: Interner, R: TypeRelation<I>>(
b_arg: I::GenericArgs,
) -> RelateResult<I, I::GenericArgs> {
relation.tcx().mk_args_from_iter(iter::zip(a_arg, b_arg).map(|(a, b)| {
relation.relate_with_variance(ty::Variance::Invariant, VarianceDiagInfo::default(), a, b)
relation.relate_with_variance(ty::Invariant, VarianceDiagInfo::default(), a, b)
}))
}
@ -145,7 +145,7 @@ pub fn relate_args_with_variances<I: Interner, R: TypeRelation<I>>(
let mut cached_ty = None;
let params = iter::zip(a_arg, b_arg).enumerate().map(|(i, (a, b))| {
let variance = variances[i];
let variance_info = if variance == ty::Variance::Invariant && fetch_ty_for_diag {
let variance_info = if variance == ty::Invariant && fetch_ty_for_diag {
let ty =
*cached_ty.get_or_insert_with(|| tcx.type_of(ty_def_id).instantiate(tcx, &a_arg));
VarianceDiagInfo::Invariant { ty, param_index: i.try_into().unwrap() }
@ -191,7 +191,7 @@ impl<I: Interner> Relate<I> for ty::FnSig<I> {
relation.relate(a, b)
} else {
relation.relate_with_variance(
ty::Variance::Contravariant,
ty::Contravariant,
VarianceDiagInfo::default(),
a,
b,
@ -311,13 +311,13 @@ impl<I: Interner> Relate<I> for ty::ExistentialProjection<I> {
}))
} else {
let term = relation.relate_with_variance(
ty::Variance::Invariant,
ty::Invariant,
VarianceDiagInfo::default(),
a.term,
b.term,
)?;
let args = relation.relate_with_variance(
ty::Variance::Invariant,
ty::Invariant,
VarianceDiagInfo::default(),
a.args,
b.args,
@ -466,9 +466,9 @@ pub fn structurally_relate_tys<I: Interner, R: TypeRelation<I>>(
}
let (variance, info) = match a_mutbl {
Mutability::Not => (ty::Variance::Covariant, VarianceDiagInfo::None),
Mutability::Not => (ty::Covariant, VarianceDiagInfo::None),
Mutability::Mut => {
(ty::Variance::Invariant, VarianceDiagInfo::Invariant { ty: a, param_index: 0 })
(ty::Invariant, VarianceDiagInfo::Invariant { ty: a, param_index: 0 })
}
};
@ -483,9 +483,9 @@ pub fn structurally_relate_tys<I: Interner, R: TypeRelation<I>>(
}
let (variance, info) = match a_mutbl {
Mutability::Not => (ty::Variance::Covariant, VarianceDiagInfo::None),
Mutability::Not => (ty::Covariant, VarianceDiagInfo::None),
Mutability::Mut => {
(ty::Variance::Invariant, VarianceDiagInfo::Invariant { ty: a, param_index: 0 })
(ty::Invariant, VarianceDiagInfo::Invariant { ty: a, param_index: 0 })
}
};
@ -612,7 +612,7 @@ pub fn structurally_relate_consts<I: Interner, R: TypeRelation<I>>(
}
let args = relation.relate_with_variance(
ty::Variance::Invariant,
ty::Invariant,
VarianceDiagInfo::default(),
au.args,
bu.args,