OptWithInfcx naming nits, trait bound simplifications

compiler/rustc_infer/src/infer/mod.rs

@@ -341,7 +341,9 @@ pub struct InferCtxt<'tcx> {
     next_trait_solver: bool,
 }
 
-impl<'tcx> ty::InferCtxtLike<TyCtxt<'tcx>> for InferCtxt<'tcx> {
+impl<'tcx> ty::InferCtxtLike for InferCtxt<'tcx> {
+    type Interner = TyCtxt<'tcx>;
+
     fn universe_of_ty(&self, ty: ty::InferTy) -> Option<ty::UniverseIndex> {
         use InferTy::*;
         match ty {

compiler/rustc_middle/src/ty/list.rs

@@ -1,7 +1,7 @@
 use crate::arena::Arena;
 use rustc_data_structures::aligned::{align_of, Aligned};
 use rustc_serialize::{Encodable, Encoder};
-use rustc_type_ir::{InferCtxtLike, OptWithInfcx};
+use rustc_type_ir::{InferCtxtLike, WithInfcx};
 use std::alloc::Layout;
 use std::cmp::Ordering;
 use std::fmt;
@@ -121,8 +121,8 @@ impl<T: fmt::Debug> fmt::Debug for List<T> {
     }
 }
 impl<'tcx, T: super::DebugWithInfcx<TyCtxt<'tcx>>> super::DebugWithInfcx<TyCtxt<'tcx>> for List<T> {
-    fn fmt<InfCtx: InferCtxtLike<TyCtxt<'tcx>>>(
-        this: OptWithInfcx<'_, TyCtxt<'tcx>, InfCtx, &Self>,
+    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
+        this: WithInfcx<'_, Infcx, &Self>,
         f: &mut core::fmt::Formatter<'_>,
     ) -> core::fmt::Result {
         fmt::Debug::fmt(&this.map(|this| this.as_slice()), f)

compiler/rustc_middle/src/ty/mod.rs

@@ -54,7 +54,7 @@ use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{ExpnId, ExpnKind, Span};
 use rustc_target::abi::{Align, FieldIdx, Integer, IntegerType, VariantIdx};
 pub use rustc_target::abi::{ReprFlags, ReprOptions};
-pub use rustc_type_ir::{DebugWithInfcx, InferCtxtLike, OptWithInfcx};
+pub use rustc_type_ir::{DebugWithInfcx, InferCtxtLike, WithInfcx};
 pub use vtable::*;
 
 use std::fmt::Debug;

compiler/rustc_middle/src/ty/structural_impls.rs

@@ -10,7 +10,7 @@ use crate::ty::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitor};
 use crate::ty::{self, AliasTy, InferConst, Lift, Term, TermKind, Ty, TyCtxt};
 use rustc_hir::def::Namespace;
 use rustc_target::abi::TyAndLayout;
-use rustc_type_ir::{ConstKind, DebugWithInfcx, InferCtxtLike, OptWithInfcx};
+use rustc_type_ir::{ConstKind, DebugWithInfcx, InferCtxtLike, WithInfcx};
 
 use std::fmt::{self, Debug};
 use std::ops::ControlFlow;
@@ -89,12 +89,12 @@ impl fmt::Debug for ty::FreeRegion {
 
 impl<'tcx> fmt::Debug for ty::FnSig<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        OptWithInfcx::new_no_ctx(self).fmt(f)
+        WithInfcx::with_no_infcx(self).fmt(f)
     }
 }
 impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for ty::FnSig<'tcx> {
-    fn fmt<InfCtx: InferCtxtLike<TyCtxt<'tcx>>>(
-        this: OptWithInfcx<'_, TyCtxt<'tcx>, InfCtx, &Self>,
+    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
+        this: WithInfcx<'_, Infcx, &Self>,
         f: &mut core::fmt::Formatter<'_>,
     ) -> core::fmt::Result {
         let sig = this.data;
@@ -149,8 +149,8 @@ impl<'tcx> fmt::Debug for ty::TraitRef<'tcx> {
 }
 
 impl<'tcx> ty::DebugWithInfcx<TyCtxt<'tcx>> for Ty<'tcx> {
-    fn fmt<InfCtx: InferCtxtLike<TyCtxt<'tcx>>>(
-        this: OptWithInfcx<'_, TyCtxt<'tcx>, InfCtx, &Self>,
+    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
+        this: WithInfcx<'_, Infcx, &Self>,
         f: &mut core::fmt::Formatter<'_>,
     ) -> core::fmt::Result {
         this.data.fmt(f)
@@ -238,12 +238,12 @@ impl<'tcx> fmt::Debug for ty::PredicateKind<'tcx> {
 
 impl<'tcx> fmt::Debug for AliasTy<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        OptWithInfcx::new_no_ctx(self).fmt(f)
+        WithInfcx::with_no_infcx(self).fmt(f)
     }
 }
 impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for AliasTy<'tcx> {
-    fn fmt<InfCtx: InferCtxtLike<TyCtxt<'tcx>>>(
-        this: OptWithInfcx<'_, TyCtxt<'tcx>, InfCtx, &Self>,
+    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
+        this: WithInfcx<'_, Infcx, &Self>,
         f: &mut core::fmt::Formatter<'_>,
     ) -> core::fmt::Result {
         f.debug_struct("AliasTy")
@@ -263,12 +263,12 @@ impl<'tcx> fmt::Debug for ty::InferConst<'tcx> {
     }
 }
 impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for ty::InferConst<'tcx> {
-    fn fmt<InfCtx: InferCtxtLike<TyCtxt<'tcx>>>(
-        this: OptWithInfcx<'_, TyCtxt<'tcx>, InfCtx, &Self>,
+    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
+        this: WithInfcx<'_, Infcx, &Self>,
         f: &mut core::fmt::Formatter<'_>,
     ) -> core::fmt::Result {
         use ty::InferConst::*;
-        match this.infcx.and_then(|infcx| infcx.universe_of_ct(*this.data)) {
+        match this.infcx.universe_of_ct(*this.data) {
             None => write!(f, "{:?}", this.data),
             Some(universe) => match *this.data {
                 Var(vid) => write!(f, "?{}_{}c", vid.index, universe.index()),
@@ -283,12 +283,12 @@ impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for ty::InferConst<'tcx> {
 
 impl<'tcx> fmt::Debug for ty::consts::Expr<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        OptWithInfcx::new_no_ctx(self).fmt(f)
+        WithInfcx::with_no_infcx(self).fmt(f)
     }
 }
 impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for ty::consts::Expr<'tcx> {
-    fn fmt<InfCtx: InferCtxtLike<TyCtxt<'tcx>>>(
-        this: OptWithInfcx<'_, TyCtxt<'tcx>, InfCtx, &Self>,
+    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
+        this: WithInfcx<'_, Infcx, &Self>,
         f: &mut core::fmt::Formatter<'_>,
     ) -> core::fmt::Result {
         match this.data {
@@ -316,12 +316,12 @@ impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for ty::consts::Expr<'tcx> {
 
 impl<'tcx> fmt::Debug for ty::UnevaluatedConst<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        OptWithInfcx::new_no_ctx(self).fmt(f)
+        WithInfcx::with_no_infcx(self).fmt(f)
     }
 }
 impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for ty::UnevaluatedConst<'tcx> {
-    fn fmt<InfCtx: InferCtxtLike<TyCtxt<'tcx>>>(
-        this: OptWithInfcx<'_, TyCtxt<'tcx>, InfCtx, &Self>,
+    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
+        this: WithInfcx<'_, Infcx, &Self>,
         f: &mut core::fmt::Formatter<'_>,
     ) -> core::fmt::Result {
         f.debug_struct("UnevaluatedConst")
@@ -333,12 +333,12 @@ impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for ty::UnevaluatedConst<'tcx> {
 
 impl<'tcx> fmt::Debug for ty::Const<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        OptWithInfcx::new_no_ctx(self).fmt(f)
+        WithInfcx::with_no_infcx(self).fmt(f)
     }
 }
 impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for ty::Const<'tcx> {
-    fn fmt<InfCtx: InferCtxtLike<TyCtxt<'tcx>>>(
-        this: OptWithInfcx<'_, TyCtxt<'tcx>, InfCtx, &Self>,
+    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
+        this: WithInfcx<'_, Infcx, &Self>,
         f: &mut core::fmt::Formatter<'_>,
     ) -> core::fmt::Result {
         // If this is a value, we spend some effort to make it look nice.
@@ -395,8 +395,8 @@ impl<'tcx> fmt::Debug for GenericArg<'tcx> {
     }
 }
 impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for GenericArg<'tcx> {
-    fn fmt<InfCtx: InferCtxtLike<TyCtxt<'tcx>>>(
-        this: OptWithInfcx<'_, TyCtxt<'tcx>, InfCtx, &Self>,
+    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
+        this: WithInfcx<'_, Infcx, &Self>,
         f: &mut core::fmt::Formatter<'_>,
     ) -> core::fmt::Result {
         match this.data.unpack() {
@@ -413,29 +413,29 @@ impl<'tcx> fmt::Debug for Region<'tcx> {
     }
 }
 impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for Region<'tcx> {
-    fn fmt<InfCtx: InferCtxtLike<TyCtxt<'tcx>>>(
-        this: OptWithInfcx<'_, TyCtxt<'tcx>, InfCtx, &Self>,
+    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
+        this: WithInfcx<'_, Infcx, &Self>,
         f: &mut core::fmt::Formatter<'_>,
     ) -> core::fmt::Result {
         write!(f, "{:?}", &this.map(|data| data.kind()))
     }
 }
 
 impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for ty::RegionVid {
-    fn fmt<InfCtx: InferCtxtLike<TyCtxt<'tcx>>>(
-        this: OptWithInfcx<'_, TyCtxt<'tcx>, InfCtx, &Self>,
+    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
+        this: WithInfcx<'_, Infcx, &Self>,
         f: &mut core::fmt::Formatter<'_>,
     ) -> core::fmt::Result {
-        match this.infcx.and_then(|infcx| infcx.universe_of_lt(*this.data)) {
+        match this.infcx.universe_of_lt(*this.data) {
             Some(universe) => write!(f, "'?{}_{}", this.data.index(), universe.index()),
             None => write!(f, "{:?}", this.data),
         }
     }
 }
 
 impl<'tcx, T: DebugWithInfcx<TyCtxt<'tcx>>> DebugWithInfcx<TyCtxt<'tcx>> for ty::Binder<'tcx, T> {
-    fn fmt<InfCtx: InferCtxtLike<TyCtxt<'tcx>>>(
-        this: OptWithInfcx<'_, TyCtxt<'tcx>, InfCtx, &Self>,
+    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
+        this: WithInfcx<'_, Infcx, &Self>,
         f: &mut core::fmt::Formatter<'_>,
     ) -> core::fmt::Result {
         f.debug_tuple("Binder")

compiler/rustc_middle/src/ty/sty.rs

@@ -683,8 +683,8 @@ pub enum ExistentialPredicate<'tcx> {
 }
 
 impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for ExistentialPredicate<'tcx> {
-    fn fmt<InfCtx: rustc_type_ir::InferCtxtLike<TyCtxt<'tcx>>>(
-        this: rustc_type_ir::OptWithInfcx<'_, TyCtxt<'tcx>, InfCtx, &Self>,
+    fn fmt<Infcx: rustc_type_ir::InferCtxtLike<Interner = TyCtxt<'tcx>>>(
+        this: rustc_type_ir::WithInfcx<'_, Infcx, &Self>,
         f: &mut core::fmt::Formatter<'_>,
     ) -> core::fmt::Result {
         fmt::Debug::fmt(&this.data, f)

compiler/rustc_type_ir/src/const_kind.rs

@@ -5,8 +5,8 @@ use std::fmt;
 use std::hash;
 
 use crate::{
-    DebruijnIndex, DebugWithInfcx, HashStableContext, InferCtxtLike, Interner, OptWithInfcx,
-    TyDecoder, TyEncoder,
+    DebruijnIndex, DebugWithInfcx, HashStableContext, InferCtxtLike, Interner, TyDecoder,
+    TyEncoder, WithInfcx,
 };
 
 use self::ConstKind::*;
@@ -231,13 +231,13 @@ impl<I: Interner> Clone for ConstKind<I> {
 
 impl<I: Interner> fmt::Debug for ConstKind<I> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        OptWithInfcx::new_no_ctx(self).fmt(f)
+        WithInfcx::with_no_infcx(self).fmt(f)
     }
 }
 
 impl<I: Interner> DebugWithInfcx<I> for ConstKind<I> {
-    fn fmt<InfCtx: InferCtxtLike<I>>(
-        this: OptWithInfcx<'_, I, InfCtx, &Self>,
+    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
+        this: WithInfcx<'_, Infcx, &Self>,
         f: &mut core::fmt::Formatter<'_>,
     ) -> core::fmt::Result {
         use ConstKind::*;

compiler/rustc_type_ir/src/debug.rs

@@ -3,47 +3,57 @@ use crate::{Interner, UniverseIndex};
 use core::fmt;
 use std::marker::PhantomData;
 
-pub trait InferCtxtLike<I: Interner> {
-    fn universe_of_ty(&self, ty: I::InferTy) -> Option<UniverseIndex>;
+pub trait InferCtxtLike {
+    type Interner: Interner;
 
-    fn universe_of_lt(&self, lt: I::InferRegion) -> Option<UniverseIndex>;
+    fn universe_of_ty(&self, ty: <Self::Interner as Interner>::InferTy) -> Option<UniverseIndex>;
 
-    fn universe_of_ct(&self, ct: I::InferConst) -> Option<UniverseIndex>;
+    fn universe_of_lt(
+        &self,
+        lt: <Self::Interner as Interner>::InferRegion,
+    ) -> Option<UniverseIndex>;
+
+    fn universe_of_ct(&self, ct: <Self::Interner as Interner>::InferConst)
+    -> Option<UniverseIndex>;
 }
 
-impl<I: Interner> InferCtxtLike<I> for core::convert::Infallible {
+pub struct NoInfcx<I>(PhantomData<I>);
+
+impl<I: Interner> InferCtxtLike for NoInfcx<I> {
+    type Interner = I;
+
     fn universe_of_ty(&self, _ty: <I as Interner>::InferTy) -> Option<UniverseIndex> {
-        match *self {}
+        None
     }
 
     fn universe_of_ct(&self, _ct: <I as Interner>::InferConst) -> Option<UniverseIndex> {
-        match *self {}
+        None
     }
 
     fn universe_of_lt(&self, _lt: <I as Interner>::InferRegion) -> Option<UniverseIndex> {
-        match *self {}
+        None
     }
 }
 
 pub trait DebugWithInfcx<I: Interner>: fmt::Debug {
-    fn fmt<InfCtx: InferCtxtLike<I>>(
-        this: OptWithInfcx<'_, I, InfCtx, &Self>,
+    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
+        this: WithInfcx<'_, Infcx, &Self>,
         f: &mut fmt::Formatter<'_>,
     ) -> fmt::Result;
 }
 
 impl<I: Interner, T: DebugWithInfcx<I> + ?Sized> DebugWithInfcx<I> for &'_ T {
-    fn fmt<InfCtx: InferCtxtLike<I>>(
-        this: OptWithInfcx<'_, I, InfCtx, &Self>,
+    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
+        this: WithInfcx<'_, Infcx, &Self>,
         f: &mut fmt::Formatter<'_>,
     ) -> fmt::Result {
         <T as DebugWithInfcx<I>>::fmt(this.map(|&data| data), f)
     }
 }
 
 impl<I: Interner, T: DebugWithInfcx<I>> DebugWithInfcx<I> for [T] {
-    fn fmt<InfCtx: InferCtxtLike<I>>(
-        this: OptWithInfcx<'_, I, InfCtx, &Self>,
+    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
+        this: WithInfcx<'_, Infcx, &Self>,
         f: &mut fmt::Formatter<'_>,
     ) -> fmt::Result {
         match f.alternate() {
@@ -70,46 +80,45 @@ impl<I: Interner, T: DebugWithInfcx<I>> DebugWithInfcx<I> for [T] {
     }
 }
 
-pub struct OptWithInfcx<'a, I: Interner, InfCtx: InferCtxtLike<I>, T> {
+pub struct WithInfcx<'a, Infcx: InferCtxtLike, T> {
     pub data: T,
-    pub infcx: Option<&'a InfCtx>,
-    _interner: PhantomData<I>,
+    pub infcx: &'a Infcx,
 }
 
-impl<I: Interner, InfCtx: InferCtxtLike<I>, T: Copy> Copy for OptWithInfcx<'_, I, InfCtx, T> {}
+impl<Infcx: InferCtxtLike, T: Copy> Copy for WithInfcx<'_, Infcx, T> {}
 
-impl<I: Interner, InfCtx: InferCtxtLike<I>, T: Clone> Clone for OptWithInfcx<'_, I, InfCtx, T> {
+impl<Infcx: InferCtxtLike, T: Clone> Clone for WithInfcx<'_, Infcx, T> {
     fn clone(&self) -> Self {
-        Self { data: self.data.clone(), infcx: self.infcx, _interner: self._interner }
+        Self { data: self.data.clone(), infcx: self.infcx }
     }
 }
 
-impl<'a, I: Interner, T> OptWithInfcx<'a, I, core::convert::Infallible, T> {
-    pub fn new_no_ctx(data: T) -> Self {
-        Self { data, infcx: None, _interner: PhantomData }
+impl<'a, I: Interner, T> WithInfcx<'a, NoInfcx<I>, T> {
+    pub fn with_no_infcx(data: T) -> Self {
+        Self { data, infcx: &NoInfcx(PhantomData) }
     }
 }
 
-impl<'a, I: Interner, InfCtx: InferCtxtLike<I>, T> OptWithInfcx<'a, I, InfCtx, T> {
-    pub fn new(data: T, infcx: &'a InfCtx) -> Self {
-        Self { data, infcx: Some(infcx), _interner: PhantomData }
+impl<'a, Infcx: InferCtxtLike, T> WithInfcx<'a, Infcx, T> {
+    pub fn new(data: T, infcx: &'a Infcx) -> Self {
+        Self { data, infcx }
     }
 
-    pub fn wrap<U>(self, u: U) -> OptWithInfcx<'a, I, InfCtx, U> {
-        OptWithInfcx { data: u, infcx: self.infcx, _interner: PhantomData }
+    pub fn wrap<U>(self, u: U) -> WithInfcx<'a, Infcx, U> {
+        WithInfcx { data: u, infcx: self.infcx }
     }
 
-    pub fn map<U>(self, f: impl FnOnce(T) -> U) -> OptWithInfcx<'a, I, InfCtx, U> {
-        OptWithInfcx { data: f(self.data), infcx: self.infcx, _interner: PhantomData }
+    pub fn map<U>(self, f: impl FnOnce(T) -> U) -> WithInfcx<'a, Infcx, U> {
+        WithInfcx { data: f(self.data), infcx: self.infcx }
     }
 
-    pub fn as_ref(&self) -> OptWithInfcx<'a, I, InfCtx, &T> {
-        OptWithInfcx { data: &self.data, infcx: self.infcx, _interner: PhantomData }
+    pub fn as_ref(&self) -> WithInfcx<'a, Infcx, &T> {
+        WithInfcx { data: &self.data, infcx: self.infcx }
     }
 }
 
-impl<I: Interner, InfCtx: InferCtxtLike<I>, T: DebugWithInfcx<I>> fmt::Debug
-    for OptWithInfcx<'_, I, InfCtx, T>
+impl<Infcx: InferCtxtLike, T: DebugWithInfcx<Infcx::Interner>> fmt::Debug
+    for WithInfcx<'_, Infcx, T>
 {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         DebugWithInfcx::fmt(self.as_ref(), f)

compiler/rustc_type_ir/src/lib.rs

@@ -34,7 +34,7 @@ mod region_kind;
 
 pub use codec::*;
 pub use const_kind::*;
-pub use debug::{DebugWithInfcx, InferCtxtLike, OptWithInfcx};
+pub use debug::{DebugWithInfcx, InferCtxtLike, WithInfcx};
 pub use flags::*;
 pub use interner::*;
 pub use region_kind::*;