Uplift OutlivesPredicate, remove a bunch of unnecessary associated types from Interner

15 files changed, 79 insertions, 75 deletions

diff --git a/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs b/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs
index 5aa8fe21381..b23ad2e1584 100644
--- a/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs
+++ b/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs
@@ -136,7 +136,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> {
 
     fn convert(
         &mut self,
-        predicate: ty::OutlivesPredicate<ty::GenericArg<'tcx>, ty::Region<'tcx>>,
+        predicate: ty::OutlivesPredicate<'tcx, ty::GenericArg<'tcx>>,
         constraint_category: ConstraintCategory<'tcx>,
     ) {
         debug!("generate: constraints at: {:#?}", self.locations);
@@ -276,7 +276,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> {
         &self,
         ty: Ty<'tcx>,
         next_outlives_predicates: &mut Vec<(
-            ty::OutlivesPredicate<ty::GenericArg<'tcx>, ty::Region<'tcx>>,
+            ty::OutlivesPredicate<'tcx, ty::GenericArg<'tcx>>,
             ConstraintCategory<'tcx>,
         )>,
     ) -> Ty<'tcx> {
diff --git a/compiler/rustc_hir_analysis/src/outlives/utils.rs b/compiler/rustc_hir_analysis/src/outlives/utils.rs
index 95290bbecf2..5086c2af3f6 100644
--- a/compiler/rustc_hir_analysis/src/outlives/utils.rs
+++ b/compiler/rustc_hir_analysis/src/outlives/utils.rs
@@ -9,7 +9,7 @@ use smallvec::smallvec;
 /// Tracks the `T: 'a` or `'a: 'a` predicates that we have inferred
 /// must be added to the struct header.
 pub(crate) type RequiredPredicates<'tcx> =
-    FxIndexMap<ty::OutlivesPredicate<GenericArg<'tcx>, ty::Region<'tcx>>, Span>;
+    FxIndexMap<ty::OutlivesPredicate<'tcx, ty::GenericArg<'tcx>>, Span>;
 
 /// Given a requirement `T: 'a` or `'b: 'a`, deduce the
 /// outlives_component and add it to `required_predicates`
diff --git a/compiler/rustc_infer/src/infer/outlives/env.rs b/compiler/rustc_infer/src/infer/outlives/env.rs
index c44a5082f68..5bcb4f29364 100644
--- a/compiler/rustc_infer/src/infer/outlives/env.rs
+++ b/compiler/rustc_infer/src/infer/outlives/env.rs
@@ -64,8 +64,7 @@ struct OutlivesEnvironmentBuilder<'tcx> {
 /// "Region-bound pairs" tracks outlives relations that are known to
 /// be true, either because of explicit where-clauses like `T: 'a` or
 /// because of implied bounds.
-pub type RegionBoundPairs<'tcx> =
-    FxIndexSet<ty::OutlivesPredicate<GenericKind<'tcx>, Region<'tcx>>>;
+pub type RegionBoundPairs<'tcx> = FxIndexSet<ty::OutlivesPredicate<'tcx, GenericKind<'tcx>>>;
 
 impl<'tcx> OutlivesEnvironment<'tcx> {
     /// Create a builder using `ParamEnv` and add explicit outlives bounds into it.
diff --git a/compiler/rustc_infer/src/infer/outlives/verify.rs b/compiler/rustc_infer/src/infer/outlives/verify.rs
index bd981c20567..7e977b9b954 100644
--- a/compiler/rustc_infer/src/infer/outlives/verify.rs
+++ b/compiler/rustc_infer/src/infer/outlives/verify.rs
@@ -94,7 +94,7 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> {
     pub fn approx_declared_bounds_from_env(
         &self,
         alias_ty: ty::AliasTy<'tcx>,
-    ) -> Vec<ty::Binder<'tcx, ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>>> {
+    ) -> Vec<ty::PolyTypeOutlivesPredicate<'tcx>> {
         let erased_alias_ty = self.tcx.erase_regions(alias_ty.to_ty(self.tcx));
         self.declared_generic_bounds_from_env_for_erased_ty(erased_alias_ty)
     }
@@ -193,7 +193,7 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> {
     fn declared_generic_bounds_from_env(
         &self,
         generic_ty: Ty<'tcx>,
-    ) -> Vec<ty::Binder<'tcx, ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>>> {
+    ) -> Vec<ty::PolyTypeOutlivesPredicate<'tcx>> {
         assert!(matches!(generic_ty.kind(), ty::Param(_) | ty::Placeholder(_)));
         self.declared_generic_bounds_from_env_for_erased_ty(generic_ty)
     }
@@ -213,7 +213,7 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> {
     fn declared_generic_bounds_from_env_for_erased_ty(
         &self,
         erased_ty: Ty<'tcx>,
-    ) -> Vec<ty::Binder<'tcx, ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>>> {
+    ) -> Vec<ty::PolyTypeOutlivesPredicate<'tcx>> {
         let tcx = self.tcx;
 
         // To start, collect bounds from user environment. Note that
diff --git a/compiler/rustc_middle/src/infer/canonical.rs b/compiler/rustc_middle/src/infer/canonical.rs
index 49bf03e9c75..dba71d88f40 100644
--- a/compiler/rustc_middle/src/infer/canonical.rs
+++ b/compiler/rustc_middle/src/infer/canonical.rs
@@ -32,7 +32,7 @@ use std::collections::hash_map::Entry;
 use crate::infer::MemberConstraint;
 use crate::mir::ConstraintCategory;
 use crate::ty::GenericArg;
-use crate::ty::{self, List, Region, Ty, TyCtxt, TypeFlags, TypeVisitableExt};
+use crate::ty::{self, List, Ty, TyCtxt, TypeFlags, TypeVisitableExt};
 
 pub type Canonical<'tcx, V> = ir::Canonical<TyCtxt<'tcx>, V>;
 pub type CanonicalVarInfo<'tcx> = ir::CanonicalVarInfo<TyCtxt<'tcx>>;
@@ -141,7 +141,7 @@ impl<'tcx, R> QueryResponse<'tcx, R> {
 }
 
 pub type QueryOutlivesConstraint<'tcx> =
-    (ty::OutlivesPredicate<GenericArg<'tcx>, Region<'tcx>>, ConstraintCategory<'tcx>);
+    (ty::OutlivesPredicate<'tcx, GenericArg<'tcx>>, ConstraintCategory<'tcx>);
 
 TrivialTypeTraversalImpls! {
     crate::infer::canonical::Certainty,
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index a457319c5f8..896114e2483 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -121,7 +121,6 @@ impl<'tcx> Interner for TyCtxt<'tcx> {
     type Abi = abi::Abi;
 
     type Const = ty::Const<'tcx>;
-    type AliasConst = ty::UnevaluatedConst<'tcx>;
     type PlaceholderConst = ty::PlaceholderConst;
     type ParamConst = ty::ParamConst;
     type BoundConst = ty::BoundVar;
@@ -137,15 +136,6 @@ impl<'tcx> Interner for TyCtxt<'tcx> {
     type ParamEnv = ty::ParamEnv<'tcx>;
     type Predicate = Predicate<'tcx>;
     type Clause = Clause<'tcx>;
-    type TraitPredicate = ty::TraitPredicate<'tcx>;
-    type RegionOutlivesPredicate = ty::RegionOutlivesPredicate<'tcx>;
-    type TypeOutlivesPredicate = ty::TypeOutlivesPredicate<'tcx>;
-    type ProjectionPredicate = ty::ProjectionPredicate<'tcx>;
-    type NormalizesTo = ty::NormalizesTo<'tcx>;
-    type SubtypePredicate = ty::SubtypePredicate<'tcx>;
-
-    type CoercePredicate = ty::CoercePredicate<'tcx>;
-    type ClosureKind = ty::ClosureKind;
 
     type Clauses = ty::Clauses<'tcx>;
 
diff --git a/compiler/rustc_middle/src/ty/predicate.rs b/compiler/rustc_middle/src/ty/predicate.rs
index 067d490078d..293cc0a7eca 100644
--- a/compiler/rustc_middle/src/ty/predicate.rs
+++ b/compiler/rustc_middle/src/ty/predicate.rs
@@ -1,9 +1,7 @@
 use rustc_data_structures::captures::Captures;
 use rustc_data_structures::intern::Interned;
 use rustc_hir::def_id::DefId;
-use rustc_macros::{
-    extension, HashStable, Lift, TyDecodable, TyEncodable, TypeFoldable, TypeVisitable,
-};
+use rustc_macros::{extension, HashStable};
 use rustc_type_ir as ir;
 use std::cmp::Ordering;
 
@@ -24,6 +22,15 @@ pub type PredicateKind<'tcx> = ir::PredicateKind<TyCtxt<'tcx>>;
 pub type NormalizesTo<'tcx> = ir::NormalizesTo<TyCtxt<'tcx>>;
 pub type CoercePredicate<'tcx> = ir::CoercePredicate<TyCtxt<'tcx>>;
 pub type SubtypePredicate<'tcx> = ir::SubtypePredicate<TyCtxt<'tcx>>;
+pub type OutlivesPredicate<'tcx, T> = ir::OutlivesPredicate<TyCtxt<'tcx>, T>;
+pub type RegionOutlivesPredicate<'tcx> = OutlivesPredicate<'tcx, ty::Region<'tcx>>;
+pub type TypeOutlivesPredicate<'tcx> = OutlivesPredicate<'tcx, Ty<'tcx>>;
+pub type PolyTraitPredicate<'tcx> = ty::Binder<'tcx, TraitPredicate<'tcx>>;
+pub type PolyRegionOutlivesPredicate<'tcx> = ty::Binder<'tcx, RegionOutlivesPredicate<'tcx>>;
+pub type PolyTypeOutlivesPredicate<'tcx> = ty::Binder<'tcx, TypeOutlivesPredicate<'tcx>>;
+pub type PolySubtypePredicate<'tcx> = ty::Binder<'tcx, SubtypePredicate<'tcx>>;
+pub type PolyCoercePredicate<'tcx> = ty::Binder<'tcx, CoercePredicate<'tcx>>;
+pub type PolyProjectionPredicate<'tcx> = ty::Binder<'tcx, ProjectionPredicate<'tcx>>;
 
 /// A statement that can be proven by a trait solver. This includes things that may
 /// show up in where clauses, such as trait predicates and projection predicates,
@@ -405,20 +412,6 @@ impl<'tcx> Clause<'tcx> {
     }
 }
 
-pub type PolyTraitPredicate<'tcx> = ty::Binder<'tcx, TraitPredicate<'tcx>>;
-
-/// `A: B`
-#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, TyEncodable, TyDecodable)]
-#[derive(HashStable, TypeFoldable, TypeVisitable, Lift)]
-pub struct OutlivesPredicate<A, B>(pub A, pub B);
-pub type RegionOutlivesPredicate<'tcx> = OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>;
-pub type TypeOutlivesPredicate<'tcx> = OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>;
-pub type PolyRegionOutlivesPredicate<'tcx> = ty::Binder<'tcx, RegionOutlivesPredicate<'tcx>>;
-pub type PolyTypeOutlivesPredicate<'tcx> = ty::Binder<'tcx, TypeOutlivesPredicate<'tcx>>;
-pub type PolySubtypePredicate<'tcx> = ty::Binder<'tcx, SubtypePredicate<'tcx>>;
-pub type PolyCoercePredicate<'tcx> = ty::Binder<'tcx, CoercePredicate<'tcx>>;
-pub type PolyProjectionPredicate<'tcx> = Binder<'tcx, ProjectionPredicate<'tcx>>;
-
 pub trait ToPolyTraitRef<'tcx> {
     fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx>;
 }
@@ -545,10 +538,8 @@ impl<'tcx> UpcastFrom<TyCtxt<'tcx>, PolyRegionOutlivesPredicate<'tcx>> for Predi
     }
 }
 
-impl<'tcx> UpcastFrom<TyCtxt<'tcx>, OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>>
-    for Predicate<'tcx>
-{
-    fn upcast_from(from: OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>, tcx: TyCtxt<'tcx>) -> Self {
+impl<'tcx> UpcastFrom<TyCtxt<'tcx>, TypeOutlivesPredicate<'tcx>> for Predicate<'tcx> {
+    fn upcast_from(from: TypeOutlivesPredicate<'tcx>, tcx: TyCtxt<'tcx>) -> Self {
         ty::Binder::dummy(PredicateKind::Clause(ClauseKind::TypeOutlives(from))).upcast(tcx)
     }
 }
diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs
index f0bd071e451..a1ead1bb59f 100644
--- a/compiler/rustc_middle/src/ty/print/pretty.rs
+++ b/compiler/rustc_middle/src/ty/print/pretty.rs
@@ -2860,10 +2860,9 @@ where
     }
 }
 
-impl<'tcx, T, U, P: PrettyPrinter<'tcx>> Print<'tcx, P> for ty::OutlivesPredicate<T, U>
+impl<'tcx, T, P: PrettyPrinter<'tcx>> Print<'tcx, P> for ty::OutlivesPredicate<'tcx, T>
 where
     T: Print<'tcx, P>,
-    U: Print<'tcx, P>,
 {
     fn print(&self, cx: &mut P) -> Result<(), PrintError> {
         define_scoped_cx!(cx);
@@ -3016,10 +3015,7 @@ forward_display_to_print! {
     ty::Region<'tcx>,
     Ty<'tcx>,
     &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
-    ty::Const<'tcx>,
-
-    ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>,
-    ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>
+    ty::Const<'tcx>
 }
 
 define_print! {
diff --git a/compiler/rustc_smir/src/rustc_smir/convert/ty.rs b/compiler/rustc_smir/src/rustc_smir/convert/ty.rs
index 15447983abb..be20924670c 100644
--- a/compiler/rustc_smir/src/rustc_smir/convert/ty.rs
+++ b/compiler/rustc_smir/src/rustc_smir/convert/ty.rs
@@ -707,12 +707,11 @@ impl<'tcx> Stable<'tcx> for ty::TraitPredicate<'tcx> {
     }
 }
 
-impl<'tcx, A, B, U, V> Stable<'tcx> for ty::OutlivesPredicate<A, B>
+impl<'tcx, T> Stable<'tcx> for ty::OutlivesPredicate<'tcx, T>
 where
-    A: Stable<'tcx, T = U>,
-    B: Stable<'tcx, T = V>,
+    T: Stable<'tcx>,
 {
-    type T = stable_mir::ty::OutlivesPredicate<U, V>;
+    type T = stable_mir::ty::OutlivesPredicate<T::T, Region>;
 
     fn stable(&self, tables: &mut Tables<'_>) -> Self::T {
         let ty::OutlivesPredicate(a, b) = self;
diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs
index f7e84a46639..00cc77e71e7 100644
--- a/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs
+++ b/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs
@@ -162,8 +162,7 @@ pub fn compute_implied_outlives_bounds_compat_inner<'tcx>(
     let mut checked_wf_args = rustc_data_structures::fx::FxHashSet::default();
     let mut wf_args = vec![ty.into()];
 
-    let mut outlives_bounds: Vec<ty::OutlivesPredicate<ty::GenericArg<'tcx>, ty::Region<'tcx>>> =
-        vec![];
+    let mut outlives_bounds: Vec<ty::OutlivesPredicate<'tcx, ty::GenericArg<'tcx>>> = vec![];
 
     while let Some(arg) = wf_args.pop() {
         if !checked_wf_args.insert(arg) {
diff --git a/compiler/rustc_type_ir/src/const_kind.rs b/compiler/rustc_type_ir/src/const_kind.rs
index af07e9ff96b..7076df2893f 100644
--- a/compiler/rustc_type_ir/src/const_kind.rs
+++ b/compiler/rustc_type_ir/src/const_kind.rs
@@ -5,7 +5,7 @@ use rustc_macros::{HashStable_NoContext, TyDecodable, TyEncodable};
 use rustc_type_ir_macros::{Lift_Generic, TypeFoldable_Generic, TypeVisitable_Generic};
 use std::fmt;
 
-use crate::{DebruijnIndex, DebugWithInfcx, InferCtxtLike, Interner, WithInfcx};
+use crate::{self as ty, DebruijnIndex, DebugWithInfcx, InferCtxtLike, Interner, WithInfcx};
 
 use self::ConstKind::*;
 
@@ -29,7 +29,7 @@ pub enum ConstKind<I: Interner> {
     /// An unnormalized const item such as an anon const or assoc const or free const item.
     /// Right now anything other than anon consts does not actually work properly but this
     /// should
-    Unevaluated(I::AliasConst),
+    Unevaluated(ty::UnevaluatedConst<I>),
 
     /// Used to hold computed value.
     Value(I::ValueConst),
diff --git a/compiler/rustc_type_ir/src/interner.rs b/compiler/rustc_type_ir/src/interner.rs
index 2ab81dfff32..9b8bb210ff4 100644
--- a/compiler/rustc_type_ir/src/interner.rs
+++ b/compiler/rustc_type_ir/src/interner.rs
@@ -76,7 +76,6 @@ pub trait Interner:
 
     // Kinds of consts
     type Const: Const<Self>;
-    type AliasConst: Copy + DebugWithInfcx<Self> + Hash + Eq;
     type PlaceholderConst: PlaceholderLike;
     type ParamConst: Copy + Debug + Hash + Eq;
     type BoundConst: Copy + Debug + Hash + Eq + BoundVarLike<Self>;
@@ -94,14 +93,6 @@ pub trait Interner:
     type ParamEnv: Copy + Debug + Hash + Eq;
     type Predicate: Predicate<Self>;
     type Clause: Clause<Self>;
-    type TraitPredicate: Copy + Debug + Hash + Eq + TypeVisitable<Self>;
-    type RegionOutlivesPredicate: Copy + Debug + Hash + Eq + TypeVisitable<Self>;
-    type TypeOutlivesPredicate: Copy + Debug + Hash + Eq + TypeVisitable<Self>;
-    type ProjectionPredicate: Copy + Debug + Hash + Eq + TypeVisitable<Self>;
-    type NormalizesTo: Copy + Debug + Hash + Eq + TypeVisitable<Self>;
-    type SubtypePredicate: Copy + Debug + Hash + Eq + TypeVisitable<Self>;
-    type CoercePredicate: Copy + Debug + Hash + Eq + TypeVisitable<Self>;
-    type ClosureKind: Copy + Debug + Hash + Eq + TypeVisitable<Self>;
     type Clauses: Copy + Debug + Hash + Eq + TypeSuperVisitable<Self> + Flags;
 
     fn mk_canonical_var_infos(self, infos: &[CanonicalVarInfo<Self>]) -> Self::CanonicalVars;
diff --git a/compiler/rustc_type_ir/src/ir_print.rs b/compiler/rustc_type_ir/src/ir_print.rs
index 6d575b8e442..d57d0816680 100644
--- a/compiler/rustc_type_ir/src/ir_print.rs
+++ b/compiler/rustc_type_ir/src/ir_print.rs
@@ -2,7 +2,8 @@ use std::fmt;
 
 use crate::{
     AliasTerm, AliasTy, Binder, CoercePredicate, ExistentialProjection, ExistentialTraitRef, FnSig,
-    Interner, NormalizesTo, ProjectionPredicate, SubtypePredicate, TraitPredicate, TraitRef,
+    Interner, NormalizesTo, OutlivesPredicate, ProjectionPredicate, SubtypePredicate,
+    TraitPredicate, TraitRef,
 };
 
 pub trait IrPrint<T> {
@@ -58,3 +59,12 @@ define_display_via_print!(
 );
 
 define_debug_via_print!(TraitRef, ExistentialTraitRef, ExistentialProjection);
+
+impl<I: Interner, T> fmt::Display for OutlivesPredicate<I, T>
+where
+    I: IrPrint<OutlivesPredicate<I, T>>,
+{
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        <I as IrPrint<OutlivesPredicate<I, T>>>::print(self, fmt)
+    }
+}
diff --git a/compiler/rustc_type_ir/src/predicate.rs b/compiler/rustc_type_ir/src/predicate.rs
index b4f3d62f10e..4e12c6b3d67 100644
--- a/compiler/rustc_type_ir/src/predicate.rs
+++ b/compiler/rustc_type_ir/src/predicate.rs
@@ -6,10 +6,39 @@ use rustc_macros::{Decodable, Encodable, HashStable_NoContext, TyDecodable, TyEn
 use rustc_type_ir_macros::{Lift_Generic, TypeFoldable_Generic, TypeVisitable_Generic};
 
 use crate::inherent::*;
+use crate::lift::Lift;
 use crate::upcast::Upcast;
 use crate::visit::TypeVisitableExt as _;
 use crate::{self as ty, DebugWithInfcx, InferCtxtLike, Interner, WithInfcx};
 
+/// `A: 'region`
+#[derive(derivative::Derivative)]
+#[derivative(
+    Clone(bound = "A: Clone"),
+    Copy(bound = "A: Copy"),
+    Hash(bound = "A: Hash"),
+    PartialEq(bound = "A: PartialEq"),
+    Eq(bound = "A: Eq"),
+    Debug(bound = "A: fmt::Debug")
+)]
+#[derive(TypeVisitable_Generic, TypeFoldable_Generic)]
+#[cfg_attr(feature = "nightly", derive(TyDecodable, TyEncodable, HashStable_NoContext))]
+pub struct OutlivesPredicate<I: Interner, A>(pub A, pub I::Region);
+
+// FIXME: We manually derive `Lift` because the `derive(Lift_Generic)` doesn't
+// understand how to turn `A` to `A::Lifted` in the output `type Lifted`.
+impl<I: Interner, U: Interner, A> Lift<U> for OutlivesPredicate<I, A>
+where
+    A: Lift<U>,
+    I::Region: Lift<U, Lifted = U::Region>,
+{
+    type Lifted = OutlivesPredicate<U, A::Lifted>;
+
+    fn lift_to_tcx(self, tcx: U) -> Option<Self::Lifted> {
+        Some(OutlivesPredicate(self.0.lift_to_tcx(tcx)?, self.1.lift_to_tcx(tcx)?))
+    }
+}
+
 /// A complete reference to a trait. These take numerous guises in syntax,
 /// but perhaps the most recognizable form is in a where-clause:
 /// ```ignore (illustrative)
diff --git a/compiler/rustc_type_ir/src/predicate_kind.rs b/compiler/rustc_type_ir/src/predicate_kind.rs
index c477ab14153..efe270ed608 100644
--- a/compiler/rustc_type_ir/src/predicate_kind.rs
+++ b/compiler/rustc_type_ir/src/predicate_kind.rs
@@ -3,7 +3,7 @@ use rustc_macros::{Decodable, Encodable, HashStable_NoContext, TyDecodable, TyEn
 use rustc_type_ir_macros::{TypeFoldable_Generic, TypeVisitable_Generic};
 use std::fmt;
 
-use crate::Interner;
+use crate::{self as ty, Interner};
 
 /// A clause is something that can appear in where bounds or be inferred
 /// by implied bounds.
@@ -15,17 +15,17 @@ pub enum ClauseKind<I: Interner> {
     /// Corresponds to `where Foo: Bar<A, B, C>`. `Foo` here would be
     /// the `Self` type of the trait reference and `A`, `B`, and `C`
     /// would be the type parameters.
-    Trait(I::TraitPredicate),
+    Trait(ty::TraitPredicate<I>),
 
-    /// `where 'a: 'b`
-    RegionOutlives(I::RegionOutlivesPredicate),
+    /// `where 'a: 'r`
+    RegionOutlives(ty::OutlivesPredicate<I, I::Region>),
 
-    /// `where T: 'a`
-    TypeOutlives(I::TypeOutlivesPredicate),
+    /// `where T: 'r`
+    TypeOutlives(ty::OutlivesPredicate<I, I::Ty>),
 
     /// `where <T as TraitRef>::Name == X`, approximately.
     /// See the `ProjectionPredicate` struct for details.
-    Projection(I::ProjectionPredicate),
+    Projection(ty::ProjectionPredicate<I>),
 
     /// Ensures that a const generic argument to a parameter `const N: u8`
     /// is of type `u8`.
@@ -75,7 +75,7 @@ pub enum PredicateKind<I: Interner> {
     /// This obligation is created most often when we have two
     /// unresolved type variables and hence don't have enough
     /// information to process the subtyping obligation yet.
-    Subtype(I::SubtypePredicate),
+    Subtype(ty::SubtypePredicate<I>),
 
     /// `T1` coerced to `T2`
     ///
@@ -85,7 +85,7 @@ pub enum PredicateKind<I: Interner> {
     /// obligation yet. At the moment, we actually process coercions
     /// very much like subtyping and don't handle the full coercion
     /// logic.
-    Coerce(I::CoercePredicate),
+    Coerce(ty::CoercePredicate<I>),
 
     /// Constants must be equal. The first component is the const that is expected.
     ConstEquate(I::Const, I::Const),
@@ -102,7 +102,7 @@ pub enum PredicateKind<I: Interner> {
     /// `T as Trait>::Assoc`, `Projection(<T as Trait>::Assoc, ?x)` constrains `?x`
     /// to `<T as Trait>::Assoc` while `NormalizesTo(<T as Trait>::Assoc, ?x)`
     /// results in `NoSolution`.
-    NormalizesTo(I::NormalizesTo),
+    NormalizesTo(ty::NormalizesTo<I>),
 
     /// Separate from `ClauseKind::Projection` which is used for normalization in new solver.
     /// This predicate requires two terms to be equal to eachother.