always use GenericArgsRef

compiler/rustc_hir_typeck/src/method/mod.rs

@@ -315,7 +315,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         trait_def_id: DefId,
         self_ty: Ty<'tcx>,
         opt_input_types: Option<&[Ty<'tcx>]>,
-    ) -> (traits::PredicateObligation<'tcx>, &'tcx ty::List<ty::GenericArg<'tcx>>) {
+    ) -> (traits::PredicateObligation<'tcx>, ty::GenericArgsRef<'tcx>) {
         // Construct a trait-reference `self_ty : Trait<input_tys>`
         let args = GenericArgs::for_item(self.tcx, trait_def_id, |param, _| {
             match param.kind {
@@ -365,7 +365,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         m_name: Ident,
         trait_def_id: DefId,
         obligation: traits::PredicateObligation<'tcx>,
-        args: &'tcx ty::List<ty::GenericArg<'tcx>>,
+        args: ty::GenericArgsRef<'tcx>,
     ) -> Option<InferOk<'tcx, MethodCallee<'tcx>>> {
         debug!(?obligation);
 

compiler/rustc_hir_typeck/src/pat.rs

@@ -1676,7 +1676,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         unmentioned_fields: &mut Vec<(&'tcx ty::FieldDef, Ident)>,
         pat: &'tcx Pat<'tcx>,
         variant: &ty::VariantDef,
-        args: &'tcx ty::List<ty::GenericArg<'tcx>>,
+        args: ty::GenericArgsRef<'tcx>,
     ) -> Diag<'tcx> {
         let tcx = self.tcx;
         let (field_names, t, plural) = if let [field] = inexistent_fields {

compiler/rustc_lint/src/for_loops_over_fallibles.rs

@@ -9,7 +9,7 @@ use crate::{
 use hir::{Expr, Pat};
 use rustc_hir as hir;
 use rustc_infer::{infer::TyCtxtInferExt, traits::ObligationCause};
-use rustc_middle::ty::{self, List};
+use rustc_middle::ty;
 use rustc_session::{declare_lint, declare_lint_pass};
 use rustc_span::{sym, Span};
 use rustc_trait_selection::traits::ObligationCtxt;
@@ -123,7 +123,7 @@ fn extract_iterator_next_call<'tcx>(
 fn suggest_question_mark<'tcx>(
     cx: &LateContext<'tcx>,
     adt: ty::AdtDef<'tcx>,
-    args: &List<ty::GenericArg<'tcx>>,
+    args: ty::GenericArgsRef<'tcx>,
     span: Span,
 ) -> bool {
     let Some(body_id) = cx.enclosing_body else { return false };

compiler/rustc_middle/src/ty/context.rs

@@ -2331,7 +2331,7 @@ impl<'tcx> TyCtxt<'tcx> {
     pub fn mk_args_from_iter<I, T>(self, iter: I) -> T::Output
     where
         I: Iterator<Item = T>,
-        T: CollectAndApply<GenericArg<'tcx>, &'tcx List<GenericArg<'tcx>>>,
+        T: CollectAndApply<GenericArg<'tcx>, ty::GenericArgsRef<'tcx>>,
     {
         T::collect_and_apply(iter, |xs| self.mk_args(xs))
     }

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -977,7 +977,7 @@ pub trait PrettyPrinter<'tcx>: Printer<'tcx> + fmt::Write {
     fn pretty_print_opaque_impl_type(
         &mut self,
         def_id: DefId,
-        args: &'tcx ty::List<ty::GenericArg<'tcx>>,
+        args: ty::GenericArgsRef<'tcx>,
     ) -> Result<(), PrintError> {
         let tcx = self.tcx();
 

compiler/rustc_trait_selection/src/traits/misc.rs

@@ -10,7 +10,7 @@ use rustc_infer::infer::canonical::Canonical;
 use rustc_infer::infer::{RegionResolutionError, TyCtxtInferExt};
 use rustc_infer::traits::query::NoSolution;
 use rustc_infer::{infer::outlives::env::OutlivesEnvironment, traits::FulfillmentError};
-use rustc_middle::ty::{self, AdtDef, GenericArg, List, Ty, TyCtxt, TypeVisitableExt};
+use rustc_middle::ty::{self, AdtDef, Ty, TyCtxt, TypeVisitableExt};
 use rustc_span::DUMMY_SP;
 
 use super::outlives_bounds::InferCtxtExt;
@@ -129,7 +129,7 @@ pub fn all_fields_implement_trait<'tcx>(
     param_env: ty::ParamEnv<'tcx>,
     self_type: Ty<'tcx>,
     adt: AdtDef<'tcx>,
-    args: &'tcx List<GenericArg<'tcx>>,
+    args: ty::GenericArgsRef<'tcx>,
     parent_cause: ObligationCause<'tcx>,
     lang_item: LangItem,
 ) -> Result<(), Vec<(&'tcx ty::FieldDef, Ty<'tcx>, InfringingFieldsReason<'tcx>)>> {

src/tools/clippy/clippy_lints/src/default_union_representation.rs

@@ -2,7 +2,7 @@ use clippy_utils::diagnostics::span_lint_and_help;
 use rustc_hir::{HirId, Item, ItemKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::layout::LayoutOf;
-use rustc_middle::ty::{self, FieldDef, GenericArg, List};
+use rustc_middle::ty::{self, FieldDef};
 use rustc_session::declare_lint_pass;
 use rustc_span::sym;
 
@@ -85,7 +85,7 @@ fn is_union_with_two_non_zst_fields<'tcx>(cx: &LateContext<'tcx>, item: &Item<'t
     }
 }
 
-fn is_zst<'tcx>(cx: &LateContext<'tcx>, field: &FieldDef, args: &'tcx List<GenericArg<'tcx>>) -> bool {
+fn is_zst<'tcx>(cx: &LateContext<'tcx>, field: &FieldDef, args: ty::GenericArgsRef<'tcx>) -> bool {
     let ty = field.ty(cx.tcx, args);
     if let Ok(layout) = cx.layout_of(ty) {
         layout.is_zst()

src/tools/clippy/clippy_lints/src/needless_borrows_for_generic_args.rs

@@ -13,7 +13,7 @@ use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::mir::{Rvalue, StatementKind};
 use rustc_middle::ty::{
-    self, ClauseKind, EarlyBinder, FnSig, GenericArg, GenericArgKind, List, ParamTy, ProjectionPredicate, Ty,
+    self, ClauseKind, EarlyBinder, FnSig, GenericArg, GenericArgKind, ParamTy, ProjectionPredicate, Ty,
 };
 use rustc_session::impl_lint_pass;
 use rustc_span::symbol::sym;
@@ -161,7 +161,7 @@ fn needless_borrow_count<'tcx>(
     cx: &LateContext<'tcx>,
     possible_borrowers: &mut Vec<(LocalDefId, PossibleBorrowerMap<'tcx, 'tcx>)>,
     fn_id: DefId,
-    callee_args: &'tcx List<GenericArg<'tcx>>,
+    callee_args: ty::GenericArgsRef<'tcx>,
     arg_index: usize,
     param_ty: ParamTy,
     mut expr: &Expr<'tcx>,

src/tools/clippy/clippy_utils/src/ty.rs

@@ -19,7 +19,7 @@ use rustc_middle::traits::EvaluationResult;
 use rustc_middle::ty::layout::ValidityRequirement;
 use rustc_middle::ty::{
     self, AdtDef, AliasTy, AssocKind, Binder, BoundRegion, FnSig, GenericArg, GenericArgKind, GenericArgsRef,
-    GenericParamDefKind, IntTy, List, ParamEnv, Region, RegionKind, ToPredicate, TraitRef, Ty, TyCtxt,
+    GenericParamDefKind, IntTy, ParamEnv, Region, RegionKind, ToPredicate, TraitRef, Ty, TyCtxt,
     TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor, UintTy, VariantDef, VariantDiscr,
 };
 use rustc_span::symbol::Ident;
@@ -961,7 +961,11 @@ pub struct AdtVariantInfo {
 
 impl AdtVariantInfo {
     /// Returns ADT variants ordered by size
-    pub fn new<'tcx>(cx: &LateContext<'tcx>, adt: AdtDef<'tcx>, subst: &'tcx List<GenericArg<'tcx>>) -> Vec<Self> {
+    pub fn new<'tcx>(
+        cx: &LateContext<'tcx>,
+        adt: AdtDef<'tcx>,
+        subst: GenericArgsRef<'tcx>
+    ) -> Vec<Self> {
         let mut variants_size = adt
             .variants()
             .iter()