rename `TraitRef::from_method` to `from_assoc`

also add a note to `GenericArgs::truncate_to`

2 files changed, 5 insertions, 5 deletions

diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index db56082c71a..49a4733de3b 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -290,11 +290,8 @@ impl<'tcx> Interner for TyCtxt<'tcx> {
         debug_assert_matches!(self.def_kind(def_id), DefKind::AssocTy | DefKind::AssocConst);
         let trait_def_id = self.parent(def_id);
         debug_assert_matches!(self.def_kind(trait_def_id), DefKind::Trait);
-        let trait_generics = self.generics_of(trait_def_id);
-        (
-            ty::TraitRef::new_from_args(self, trait_def_id, args.truncate_to(self, trait_generics)),
-            &args[trait_generics.count()..],
-        )
+        let trait_ref = ty::TraitRef::from_assoc(self, trait_def_id, args);
+        (trait_ref, &args[trait_ref.args.len()..])
     }
 
     fn mk_args(self, args: &[Self::GenericArg]) -> ty::GenericArgsRef<'tcx> {
diff --git a/compiler/rustc_middle/src/ty/generic_args.rs b/compiler/rustc_middle/src/ty/generic_args.rs
index 648709e88e6..3ade3a3ef51 100644
--- a/compiler/rustc_middle/src/ty/generic_args.rs
+++ b/compiler/rustc_middle/src/ty/generic_args.rs
@@ -585,6 +585,9 @@ impl<'tcx> GenericArgs<'tcx> {
         tcx.mk_args_from_iter(target_args.iter().chain(self.iter().skip(defs.count())))
     }
 
+    /// Truncates this list of generic args to have at most the number of args in `generics`.
+    ///
+    /// You might be looking for [`TraitRef::from_assoc`](super::TraitRef::from_assoc).
     pub fn truncate_to(&self, tcx: TyCtxt<'tcx>, generics: &ty::Generics) -> GenericArgsRef<'tcx> {
         tcx.mk_args(&self[..generics.count()])
     }