remove the Subst trait, always use EarlyBinder

compiler/rustc_typeck/src/astconv/mod.rs

@@ -26,7 +26,7 @@ use rustc_hir::intravisit::{walk_generics, Visitor as _};
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{GenericArg, GenericArgs, OpaqueTyOrigin};
 use rustc_middle::middle::stability::AllowUnstable;
-use rustc_middle::ty::subst::{self, GenericArgKind, InternalSubsts, Subst, SubstsRef};
+use rustc_middle::ty::subst::{self, GenericArgKind, InternalSubsts, SubstsRef};
 use rustc_middle::ty::DynKind;
 use rustc_middle::ty::GenericParamDefKind;
 use rustc_middle::ty::{

compiler/rustc_typeck/src/check/_match.rs

@@ -4,7 +4,7 @@ use rustc_errors::{Applicability, MultiSpan};
 use rustc_hir::{self as hir, ExprKind};
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_infer::traits::Obligation;
-use rustc_middle::ty::{self, Subst, ToPredicate, Ty};
+use rustc_middle::ty::{self, ToPredicate, Ty};
 use rustc_span::Span;
 use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt;
 use rustc_trait_selection::traits::{

compiler/rustc_typeck/src/check/callee.rs

@@ -17,7 +17,7 @@ use rustc_infer::{
 use rustc_middle::ty::adjustment::{
     Adjust, Adjustment, AllowTwoPhase, AutoBorrow, AutoBorrowMutability,
 };
-use rustc_middle::ty::subst::{Subst, SubstsRef};
+use rustc_middle::ty::SubstsRef;
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitable};
 use rustc_span::def_id::LocalDefId;
 use rustc_span::symbol::{sym, Ident};

compiler/rustc_typeck/src/check/closure.rs

@@ -3,7 +3,6 @@
 use super::{check_fn, Expectation, FnCtxt, GeneratorTypes};
 
 use crate::astconv::AstConv;
-use crate::rustc_middle::ty::subst::Subst;
 use hir::def::DefKind;
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;

compiler/rustc_typeck/src/check/compare_method.rs

@@ -12,8 +12,8 @@ use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKi
 use rustc_infer::infer::{self, TyCtxtInferExt};
 use rustc_infer::traits::util;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
-use rustc_middle::ty::subst::{InternalSubsts, Subst};
 use rustc_middle::ty::util::ExplicitSelf;
+use rustc_middle::ty::InternalSubsts;
 use rustc_middle::ty::{
     self, AssocItem, DefIdTree, Ty, TypeFoldable, TypeFolder, TypeSuperFoldable, TypeVisitable,
 };

compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs

@@ -20,14 +20,12 @@ use rustc_infer::infer::error_reporting::TypeAnnotationNeeded::E0282;
 use rustc_infer::infer::{InferOk, InferResult};
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow, AutoBorrowMutability};
 use rustc_middle::ty::fold::TypeFoldable;
-use rustc_middle::ty::subst::{
-    self, GenericArgKind, InternalSubsts, Subst, SubstsRef, UserSelfTy, UserSubsts,
-};
 use rustc_middle::ty::visit::TypeVisitable;
 use rustc_middle::ty::{
     self, AdtKind, CanonicalUserType, DefIdTree, EarlyBinder, GenericParamDefKind, ToPolyTraitRef,
     ToPredicate, Ty, UserType,
 };
+use rustc_middle::ty::{GenericArgKind, InternalSubsts, SubstsRef, UserSelfTy, UserSubsts};
 use rustc_session::lint;
 use rustc_span::def_id::LocalDefId;
 use rustc_span::hygiene::DesugaringKind;
@@ -559,7 +557,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// Registers an obligation for checking later, during regionck, that `arg` is well-formed.
     pub fn register_wf_obligation(
         &self,
-        arg: subst::GenericArg<'tcx>,
+        arg: ty::GenericArg<'tcx>,
         span: Span,
         code: traits::ObligationCauseCode<'tcx>,
     ) {
@@ -1271,7 +1269,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 &mut self,
                 param: &ty::GenericParamDef,
                 arg: &GenericArg<'_>,
-            ) -> subst::GenericArg<'tcx> {
+            ) -> ty::GenericArg<'tcx> {
                 match (&param.kind, arg) {
                     (GenericParamDefKind::Lifetime, GenericArg::Lifetime(lt)) => {
                         <dyn AstConv<'_>>::ast_region_to_region(self.fcx, lt, Some(param)).into()
@@ -1295,10 +1293,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
             fn inferred_kind(
                 &mut self,
-                substs: Option<&[subst::GenericArg<'tcx>]>,
+                substs: Option<&[ty::GenericArg<'tcx>]>,
                 param: &ty::GenericParamDef,
                 infer_args: bool,
-            ) -> subst::GenericArg<'tcx> {
+            ) -> ty::GenericArg<'tcx> {
                 let tcx = self.fcx.tcx();
                 match param.kind {
                     GenericParamDefKind::Lifetime => {

compiler/rustc_typeck/src/check/fn_ctxt/suggestions.rs

@@ -14,7 +14,7 @@ use rustc_hir::{
 use rustc_infer::infer::{self, TyCtxtInferExt};
 use rustc_infer::traits::{self, StatementAsExpression};
 use rustc_middle::lint::in_external_macro;
-use rustc_middle::ty::{self, Binder, IsSuggestable, Subst, ToPredicate, Ty};
+use rustc_middle::ty::{self, Binder, IsSuggestable, ToPredicate, Ty};
 use rustc_span::symbol::sym;
 use rustc_span::Span;
 use rustc_trait_selection::infer::InferCtxtExt;

compiler/rustc_typeck/src/check/intrinsic.rs

@@ -10,7 +10,6 @@ use crate::require_same_types;
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
 use rustc_middle::traits::{ObligationCause, ObligationCauseCode};
-use rustc_middle::ty::subst::Subst;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_target::spec::abi::Abi;

compiler/rustc_typeck/src/check/method/confirm.rs

@@ -10,7 +10,7 @@ use rustc_middle::traits::{ObligationCauseCode, UnifyReceiverContext};
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, PointerCast};
 use rustc_middle::ty::adjustment::{AllowTwoPhase, AutoBorrow, AutoBorrowMutability};
 use rustc_middle::ty::fold::TypeFoldable;
-use rustc_middle::ty::subst::{self, Subst, SubstsRef};
+use rustc_middle::ty::subst::{self, SubstsRef};
 use rustc_middle::ty::{self, GenericParamDefKind, Ty};
 use rustc_span::Span;
 use rustc_trait_selection::traits;

compiler/rustc_typeck/src/check/method/mod.rs

@@ -18,7 +18,6 @@ use rustc_hir as hir;
 use rustc_hir::def::{CtorOf, DefKind, Namespace};
 use rustc_hir::def_id::DefId;
 use rustc_infer::infer::{self, InferOk};
-use rustc_middle::ty::subst::Subst;
 use rustc_middle::ty::subst::{InternalSubsts, SubstsRef};
 use rustc_middle::ty::{self, DefIdTree, GenericParamDefKind, ToPredicate, Ty, TypeVisitable};
 use rustc_span::symbol::Ident;

compiler/rustc_typeck/src/check/method/probe.rs

@@ -19,9 +19,9 @@ use rustc_infer::infer::{self, InferOk, TyCtxtInferExt};
 use rustc_middle::infer::unify_key::{ConstVariableOrigin, ConstVariableOriginKind};
 use rustc_middle::middle::stability;
 use rustc_middle::ty::fast_reject::{simplify_type, TreatParams};
-use rustc_middle::ty::subst::{InternalSubsts, Subst, SubstsRef};
 use rustc_middle::ty::GenericParamDefKind;
 use rustc_middle::ty::{self, ParamEnvAnd, ToPredicate, Ty, TyCtxt, TypeFoldable, TypeVisitable};
+use rustc_middle::ty::{InternalSubsts, SubstsRef};
 use rustc_session::lint;
 use rustc_span::def_id::LocalDefId;
 use rustc_span::lev_distance::{

compiler/rustc_typeck/src/check/mod.rs

@@ -112,8 +112,8 @@ use rustc_hir::{HirIdMap, ImplicitSelfKind, Node};
 use rustc_index::bit_set::BitSet;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::subst::{InternalSubsts, Subst, SubstsRef};
 use rustc_middle::ty::{self, Ty, TyCtxt, UserType};
+use rustc_middle::ty::{InternalSubsts, SubstsRef};
 use rustc_session::config;
 use rustc_session::parse::feature_err;
 use rustc_session::Session;

compiler/rustc_typeck/src/check/wfcheck.rs

@@ -12,12 +12,12 @@ use rustc_infer::infer::outlives::obligations::TypeOutlives;
 use rustc_infer::infer::{self, InferCtxt, TyCtxtInferExt};
 use rustc_middle::mir::ConstraintCategory;
 use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::subst::{GenericArgKind, InternalSubsts, Subst};
 use rustc_middle::ty::trait_def::TraitSpecializationKind;
 use rustc_middle::ty::{
     self, AdtKind, DefIdTree, GenericParamDefKind, ToPredicate, Ty, TyCtxt, TypeFoldable,
     TypeSuperVisitable, TypeVisitable, TypeVisitor,
 };
+use rustc_middle::ty::{GenericArgKind, InternalSubsts};
 use rustc_session::parse::feature_err;
 use rustc_span::symbol::{sym, Ident, Symbol};
 use rustc_span::{Span, DUMMY_SP};

compiler/rustc_typeck/src/outlives/implicit_infer.rs

@@ -1,8 +1,8 @@
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::DefId;
-use rustc_middle::ty::subst::{GenericArg, GenericArgKind, Subst};
 use rustc_middle::ty::{self, DefIdTree, Ty, TyCtxt};
+use rustc_middle::ty::{GenericArg, GenericArgKind};
 use rustc_span::Span;
 
 use super::explicit::ExplicitPredicatesMap;