Get rid of elaborate_trait_ref{s} too

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -33,9 +33,9 @@ use rustc_middle::infer::unify_key::{ConstVariableOrigin, ConstVariableOriginKin
 use rustc_middle::middle::stability::AllowUnstable;
 use rustc_middle::ty::fold::FnMutDelegate;
 use rustc_middle::ty::subst::{self, GenericArgKind, InternalSubsts, SubstsRef};
-use rustc_middle::ty::DynKind;
 use rustc_middle::ty::GenericParamDefKind;
 use rustc_middle::ty::{self, Const, IsSuggestable, Ty, TyCtxt, TypeVisitableExt};
+use rustc_middle::ty::{DynKind, ToPredicate};
 use rustc_session::lint::builtin::{AMBIGUOUS_ASSOCIATED_ITEMS, BARE_TRAIT_OBJECTS};
 use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::edition::Edition;
@@ -1526,8 +1526,8 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
 
         for (base_trait_ref, span, constness) in regular_traits_refs_spans {
             assert_eq!(constness, ty::BoundConstness::NotConst);
-
-            for pred in traits::elaborate_trait_ref(tcx, base_trait_ref) {
+            let base_pred: ty::Predicate<'tcx> = base_trait_ref.to_predicate(tcx);
+            for pred in traits::elaborate(tcx, [base_pred]) {
                 debug!("conv_object_ty_poly_trait_ref: observing object predicate `{:?}`", pred);
 
                 let bound_predicate = pred.kind();

compiler/rustc_infer/src/traits/util.rs

@@ -166,20 +166,6 @@ impl<'tcx> Elaboratable<'tcx> for (ty::Predicate<'tcx>, Span) {
     }
 }
 
-pub fn elaborate_trait_ref<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    trait_ref: ty::PolyTraitRef<'tcx>,
-) -> Elaborator<'tcx, ty::Predicate<'tcx>> {
-    elaborate(tcx, std::iter::once(trait_ref.without_const().to_predicate(tcx)))
-}
-
-pub fn elaborate_trait_refs<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    trait_refs: impl Iterator<Item = ty::PolyTraitRef<'tcx>>,
-) -> Elaborator<'tcx, ty::Predicate<'tcx>> {
-    elaborate(tcx, trait_refs.map(|trait_ref| trait_ref.to_predicate(tcx)))
-}
-
 pub fn elaborate<'tcx, O: Elaboratable<'tcx>>(
     tcx: TyCtxt<'tcx>,
     obligations: impl IntoIterator<Item = O>,
@@ -364,17 +350,21 @@ pub fn supertraits<'tcx>(
     tcx: TyCtxt<'tcx>,
     trait_ref: ty::PolyTraitRef<'tcx>,
 ) -> impl Iterator<Item = ty::PolyTraitRef<'tcx>> {
-    FilterToTraits::new(elaborate_trait_ref(tcx, trait_ref))
+    let pred: ty::Predicate<'tcx> = trait_ref.to_predicate(tcx);
+    FilterToTraits::new(elaborate(tcx, [pred]))
 }
 
 pub fn transitive_bounds<'tcx>(
     tcx: TyCtxt<'tcx>,
     trait_refs: impl Iterator<Item = ty::PolyTraitRef<'tcx>>,
 ) -> impl Iterator<Item = ty::PolyTraitRef<'tcx>> {
-    FilterToTraits::new(elaborate_trait_refs(tcx, trait_refs))
+    FilterToTraits::new(elaborate(
+        tcx,
+        trait_refs.map(|trait_ref| -> ty::Predicate<'tcx> { trait_ref.to_predicate(tcx) }),
+    ))
 }
 
-/// A specialized variant of `elaborate_trait_refs` that only elaborates trait references that may
+/// A specialized variant of `elaborate` that only elaborates trait references that may
 /// define the given associated type `assoc_name`. It uses the
 /// `super_predicates_that_define_assoc_type` query to avoid enumerating super-predicates that
 /// aren't related to `assoc_item`. This is used when resolving types like `Self::Item` or

compiler/rustc_trait_selection/src/traits/mod.rs

@@ -58,7 +58,7 @@ pub use self::specialize::{specialization_graph, translate_substs, OverlapError}
 pub use self::structural_match::{
     search_for_adt_const_param_violation, search_for_structural_match_violation,
 };
-pub use self::util::{elaborate, elaborate_trait_ref, elaborate_trait_refs};
+pub use self::util::elaborate;
 pub use self::util::{expand_trait_aliases, TraitAliasExpander};
 pub use self::util::{get_vtable_index_of_object_method, impl_item_is_final, upcast_choices};
 pub use self::util::{

compiler/rustc_trait_selection/src/traits/object_safety.rs

@@ -8,7 +8,7 @@
 //!   - not reference the erased type `Self` except for in this receiver;
 //!   - not have generic type parameters.
 
-use super::{elaborate, elaborate_trait_ref};
+use super::elaborate;
 
 use crate::infer::TyCtxtInferExt;
 use crate::traits::query::evaluate_obligation::InferCtxtExt;
@@ -666,7 +666,8 @@ fn object_ty_for_trait<'tcx>(
     });
     debug!(?trait_predicate);
 
-    let mut elaborated_predicates: Vec<_> = elaborate_trait_ref(tcx, trait_ref)
+    let pred: ty::Predicate<'tcx> = trait_ref.to_predicate(tcx);
+    let mut elaborated_predicates: Vec<_> = elaborate(tcx, [pred])
         .filter_map(|pred| {
             debug!(?pred);
             let pred = pred.to_opt_poly_projection_pred()?;