Rollup merge of rust-lang#102492 - compiler-errors:simplify-deny-assoc-bindings, r=cjgillot

Don't lower assoc bindings just to deny them

Some clean-up: rust-lang#102338 (comment)

Author: matthiaskrgr

compiler/rustc_hir_analysis/src/astconv/generics.rs

@@ -448,8 +448,8 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         let infer_lifetimes =
             (gen_pos != GenericArgPosition::Type || infer_args) && !gen_args.has_lifetime_params();
 
-        if gen_pos != GenericArgPosition::Type && !gen_args.bindings.is_empty() {
-            Self::prohibit_assoc_ty_binding(tcx, gen_args.bindings[0].span);
+        if gen_pos != GenericArgPosition::Type && let Some(b) = gen_args.bindings.first() {
+            Self::prohibit_assoc_ty_binding(tcx, b.span);
         }
 
         let explicit_late_bound =

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -276,9 +276,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             item_segment.infer_args,
             None,
         );
-        let assoc_bindings = self.create_assoc_bindings_for_generic_args(item_segment.args());
-
-        if let Some(b) = assoc_bindings.first() {
+        if let Some(b) = item_segment.args().bindings.first() {
             Self::prohibit_assoc_ty_binding(self.tcx(), b.span);
         }
 
@@ -605,8 +603,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             None,
         );
 
-        let assoc_bindings = self.create_assoc_bindings_for_generic_args(item_segment.args());
-        if let Some(b) = assoc_bindings.first() {
+        if let Some(b) = item_segment.args().bindings.first() {
             Self::prohibit_assoc_ty_binding(self.tcx(), b.span);
         }
 
@@ -794,8 +791,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             trait_segment,
             is_impl,
         );
-        let assoc_bindings = self.create_assoc_bindings_for_generic_args(trait_segment.args());
-        if let Some(b) = assoc_bindings.first() {
+        if let Some(b) = trait_segment.args().bindings.first() {
             Self::prohibit_assoc_ty_binding(self.tcx(), b.span);
         }
         ty::TraitRef::new(trait_def_id, substs)
@@ -2207,8 +2203,8 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
 
         for segment in segments {
             // Only emit the first error to avoid overloading the user with error messages.
-            if let [binding, ..] = segment.args().bindings {
-                Self::prohibit_assoc_ty_binding(self.tcx(), binding.span);
+            if let Some(b) = segment.args().bindings.first() {
+                Self::prohibit_assoc_ty_binding(self.tcx(), b.span);
                 return true;
             }
         }