Show only assoc type args in the correct arg pos

crates/hir/src/lib.rs

@@ -41,6 +41,7 @@ use hir_def::{
     adt::{ReprKind, VariantData},
     body::{BodyDiagnostic, SyntheticSyntax},
     expr::{BindingAnnotation, LabelId, Pat, PatId},
+    generics::{TypeOrConstParamData, TypeParamProvenance},
     item_tree::ItemTreeNode,
     lang_item::LangItemTarget,
     nameres::{self, diagnostics::DefDiagnostic},
@@ -1707,6 +1708,22 @@ impl Trait {
     pub fn is_unsafe(&self, db: &dyn HirDatabase) -> bool {
         db.trait_data(self.id).is_unsafe
     }
+
+    pub fn type_parameters(&self, db: &dyn HirDatabase) -> Vec<TypeOrConstParamData> {
+        db.generic_params(GenericDefId::from(self.id))
+            .type_or_consts
+            .iter()
+            .filter(|(_, ty)| match ty {
+                TypeOrConstParamData::TypeParamData(ty)
+                    if ty.provenance != TypeParamProvenance::TypeParamList =>
+                {
+                    false
+                }
+                _ => true,
+            })
+            .map(|(_, ty)|ty.clone())
+            .collect()
+        }
 }
 
 impl HasVisibility for Trait {