From b55d8a3b4917698fd6d389f05afc423086f33d97 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Fri, 10 May 2024 15:43:27 -0400
Subject: [PATCH] Apply nits, make some bounds into supertraits on inherent
 traits

---
 compiler/rustc_middle/src/ty/predicate.rs |  2 +
 compiler/rustc_traits/src/type_op.rs      |  2 +-
 compiler/rustc_type_ir/src/inherent.rs    | 50 ++++++++++++++++++---
 compiler/rustc_type_ir/src/interner.rs    | 55 ++++-------------------
 compiler/rustc_type_ir/src/ir_print.rs    |  2 +-
 compiler/rustc_type_ir/src/trait_ref.rs   |  2 +-
 6 files changed, 57 insertions(+), 56 deletions(-)

diff --git a/compiler/rustc_middle/src/ty/predicate.rs b/compiler/rustc_middle/src/ty/predicate.rs
index 2279e27c8db..5387036d409 100644
--- a/compiler/rustc_middle/src/ty/predicate.rs
+++ b/compiler/rustc_middle/src/ty/predicate.rs
@@ -30,6 +30,8 @@ pub struct Predicate<'tcx>(
     pub(super) Interned<'tcx, WithCachedTypeInfo<ty::Binder<'tcx, PredicateKind<'tcx>>>>,
 );
 
+impl<'tcx> rustc_type_ir::inherent::Predicate<TyCtxt<'tcx>> for Predicate<'tcx> {}
+
 impl<'tcx> rustc_type_ir::visit::Flags for Predicate<'tcx> {
     fn flags(&self) -> TypeFlags {
         self.0.flags
diff --git a/compiler/rustc_traits/src/type_op.rs b/compiler/rustc_traits/src/type_op.rs
index 85c98bfd5dc..b6a59a4ad3a 100644
--- a/compiler/rustc_traits/src/type_op.rs
+++ b/compiler/rustc_traits/src/type_op.rs
@@ -3,7 +3,7 @@ use rustc_infer::infer::TyCtxtInferExt;
 use rustc_middle::query::Providers;
 use rustc_middle::traits::query::NoSolution;
 use rustc_middle::ty::{Clause, ParamEnvAnd};
-use rustc_middle::ty::{FnSig, Lift, PolyFnSig, Ty, TyCtxt, TypeFoldable};
+use rustc_middle::ty::{FnSig, PolyFnSig, Ty, TyCtxt, TypeFoldable};
 use rustc_trait_selection::infer::InferCtxtBuilderExt;
 use rustc_trait_selection::traits::query::normalize::QueryNormalizeExt;
 use rustc_trait_selection::traits::query::type_op::ascribe_user_type::{
diff --git a/compiler/rustc_type_ir/src/inherent.rs b/compiler/rustc_type_ir/src/inherent.rs
index 84aeeae31d8..0fd34e0a65f 100644
--- a/compiler/rustc_type_ir/src/inherent.rs
+++ b/compiler/rustc_type_ir/src/inherent.rs
@@ -1,33 +1,69 @@
-use crate::{BoundVar, DebruijnIndex, Interner, UniverseIndex};
+use std::fmt::Debug;
+use std::hash::Hash;
 
-pub trait Ty<I: Interner<Ty = Self>> {
+use crate::fold::TypeSuperFoldable;
+use crate::visit::{Flags, TypeSuperVisitable};
+use crate::{
+    BoundVar, ConstKind, DebruijnIndex, DebugWithInfcx, Interner, RegionKind, TyKind, UniverseIndex,
+};
+
+pub trait Ty<I: Interner<Ty = Self>>:
+    Copy
+    + DebugWithInfcx<I>
+    + Hash
+    + Eq
+    + Into<I::GenericArg>
+    + IntoKind<Kind = TyKind<I>>
+    + TypeSuperVisitable<I>
+    + TypeSuperFoldable<I>
+    + Flags
+{
     fn new_anon_bound(interner: I, debruijn: DebruijnIndex, var: BoundVar) -> Self;
 }
 
-pub trait Region<I: Interner<Region = Self>> {
+pub trait Region<I: Interner<Region = Self>>:
+    Copy + DebugWithInfcx<I> + Hash + Eq + Into<I::GenericArg> + IntoKind<Kind = RegionKind<I>> + Flags
+{
     fn new_anon_bound(interner: I, debruijn: DebruijnIndex, var: BoundVar) -> Self;
 
     fn new_static(interner: I) -> Self;
 }
 
-pub trait Const<I: Interner<Const = Self>> {
+pub trait Const<I: Interner<Const = Self>>:
+    Copy
+    + DebugWithInfcx<I>
+    + Hash
+    + Eq
+    + Into<I::GenericArg>
+    + IntoKind<Kind = ConstKind<I>>
+    + TypeSuperVisitable<I>
+    + TypeSuperFoldable<I>
+    + Flags
+{
     fn new_anon_bound(interner: I, debruijn: DebruijnIndex, var: BoundVar, ty: I::Ty) -> Self;
 
     fn ty(self) -> I::Ty;
 }
 
-pub trait GenericsOf<I: Interner> {
+pub trait GenericsOf<I: Interner<GenericsOf = Self>> {
     fn count(&self) -> usize;
 }
 
-pub trait GenericArgs<I: Interner> {
+pub trait GenericArgs<I: Interner<GenericArgs = Self>>:
+    Copy + DebugWithInfcx<I> + Hash + Eq + IntoIterator<Item = I::GenericArg>
+{
     fn type_at(self, i: usize) -> I::Ty;
 
     fn identity_for_item(interner: I, def_id: I::DefId) -> I::GenericArgs;
 }
 
+pub trait Predicate<I: Interner<Predicate = Self>>:
+    Copy + Debug + Hash + Eq + TypeSuperVisitable<I> + TypeSuperFoldable<I> + Flags
+{
+}
+
 /// Common capabilities of placeholder kinds
-pub trait PlaceholderLike {
+pub trait PlaceholderLike: Copy + Debug + Hash + Eq {
     fn universe(self) -> UniverseIndex;
     fn var(self) -> BoundVar;
 
diff --git a/compiler/rustc_type_ir/src/interner.rs b/compiler/rustc_type_ir/src/interner.rs
index 32f07b1ff61..c8bd7fea11b 100644
--- a/compiler/rustc_type_ir/src/interner.rs
+++ b/compiler/rustc_type_ir/src/interner.rs
@@ -2,23 +2,17 @@ use smallvec::SmallVec;
 use std::fmt::Debug;
 use std::hash::Hash;
 
-use crate::fold::TypeSuperFoldable;
 use crate::inherent::*;
 use crate::ir_print::IrPrint;
 use crate::visit::{Flags, TypeSuperVisitable, TypeVisitable};
-use crate::{CanonicalVarInfo, ConstKind, DebugWithInfcx, RegionKind, TraitRef, TyKind};
+use crate::{CanonicalVarInfo, DebugWithInfcx, TraitRef};
 
 pub trait Interner: Sized + Copy + IrPrint<TraitRef<Self>> {
     type DefId: Copy + Debug + Hash + Eq;
     type DefiningOpaqueTypes: Copy + Debug + Hash + Default + Eq + TypeVisitable<Self>;
     type AdtDef: Copy + Debug + Hash + Eq;
 
-    type GenericArgs: Copy
-        + DebugWithInfcx<Self>
-        + Hash
-        + Eq
-        + IntoIterator<Item = Self::GenericArg>
-        + GenericArgs<Self>;
+    type GenericArgs: GenericArgs<Self>;
     type GenericArg: Copy + DebugWithInfcx<Self> + Hash + Eq;
     type Term: Copy + Debug + Hash + Eq;
 
@@ -29,21 +23,12 @@ pub trait Interner: Sized + Copy + IrPrint<TraitRef<Self>> {
     type CanonicalVars: Copy + Debug + Hash + Eq + IntoIterator<Item = CanonicalVarInfo<Self>>;
 
     // Kinds of tys
-    type Ty: Copy
-        + DebugWithInfcx<Self>
-        + Hash
-        + Eq
-        + Into<Self::GenericArg>
-        + IntoKind<Kind = TyKind<Self>>
-        + TypeSuperVisitable<Self>
-        + TypeSuperFoldable<Self>
-        + Flags
-        + Ty<Self>;
+    type Ty: Ty<Self>;
     type Tys: Copy + Debug + Hash + Eq + IntoIterator<Item = Self::Ty>;
     type AliasTy: Copy + DebugWithInfcx<Self> + Hash + Eq;
     type ParamTy: Copy + Debug + Hash + Eq;
     type BoundTy: Copy + Debug + Hash + Eq;
-    type PlaceholderTy: Copy + Debug + Hash + Eq + PlaceholderLike;
+    type PlaceholderTy: PlaceholderLike;
 
     // Things stored inside of tys
     type ErrorGuaranteed: Copy + Debug + Hash + Eq;
@@ -53,46 +38,24 @@ pub trait Interner: Sized + Copy + IrPrint<TraitRef<Self>> {
     type Pat: Copy + Debug + Hash + Eq + DebugWithInfcx<Self>;
 
     // Kinds of consts
-    type Const: Copy
-        + DebugWithInfcx<Self>
-        + Hash
-        + Eq
-        + Into<Self::GenericArg>
-        + IntoKind<Kind = ConstKind<Self>>
-        + TypeSuperVisitable<Self>
-        + TypeSuperFoldable<Self>
-        + Flags
-        + Const<Self>;
+    type Const: Const<Self>;
     type AliasConst: Copy + DebugWithInfcx<Self> + Hash + Eq;
-    type PlaceholderConst: Copy + Debug + Hash + Eq + PlaceholderLike;
+    type PlaceholderConst: PlaceholderLike;
     type ParamConst: Copy + Debug + Hash + Eq;
     type BoundConst: Copy + Debug + Hash + Eq;
     type ValueConst: Copy + Debug + Hash + Eq;
     type ExprConst: Copy + DebugWithInfcx<Self> + Hash + Eq;
 
     // Kinds of regions
-    type Region: Copy
-        + DebugWithInfcx<Self>
-        + Hash
-        + Eq
-        + Into<Self::GenericArg>
-        + IntoKind<Kind = RegionKind<Self>>
-        + Flags
-        + Region<Self>;
+    type Region: Region<Self>;
     type EarlyParamRegion: Copy + Debug + Hash + Eq;
     type LateParamRegion: Copy + Debug + Hash + Eq;
     type BoundRegion: Copy + Debug + Hash + Eq;
     type InferRegion: Copy + DebugWithInfcx<Self> + Hash + Eq;
-    type PlaceholderRegion: Copy + Debug + Hash + Eq + PlaceholderLike;
+    type PlaceholderRegion: PlaceholderLike;
 
     // Predicates
-    type Predicate: Copy
-        + Debug
-        + Hash
-        + Eq
-        + TypeSuperVisitable<Self>
-        + TypeSuperFoldable<Self>
-        + Flags;
+    type Predicate: Predicate<Self>;
     type TraitPredicate: Copy + Debug + Hash + Eq;
     type RegionOutlivesPredicate: Copy + Debug + Hash + Eq;
     type TypeOutlivesPredicate: Copy + Debug + Hash + Eq;
diff --git a/compiler/rustc_type_ir/src/ir_print.rs b/compiler/rustc_type_ir/src/ir_print.rs
index 265c582ac44..84e889b486a 100644
--- a/compiler/rustc_type_ir/src/ir_print.rs
+++ b/compiler/rustc_type_ir/src/ir_print.rs
@@ -8,7 +8,7 @@ pub trait IrPrint<T> {
 }
 
 macro_rules! define_display_via_print {
-    ($($ty:ident,)*) => {
+    ($($ty:ident),+ $(,)?) => {
         $(
             impl<I: Interner> fmt::Display for $ty<I> {
                 fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
diff --git a/compiler/rustc_type_ir/src/trait_ref.rs b/compiler/rustc_type_ir/src/trait_ref.rs
index a91fd1b2911..4bd513ab7e1 100644
--- a/compiler/rustc_type_ir/src/trait_ref.rs
+++ b/compiler/rustc_type_ir/src/trait_ref.rs
@@ -31,7 +31,7 @@ pub struct TraitRef<I: Interner> {
     pub args: I::GenericArgs,
     /// This field exists to prevent the creation of `TraitRef` without
     /// calling [`TraitRef::new`].
-    pub(super) _use_trait_ref_new_instead: (),
+    _use_trait_ref_new_instead: (),
 }
 
 impl<I: Interner> TraitRef<I> {