Support generic function in generate_function assist

Author: lowr

crates/hir/src/lib.rs

@@ -2165,6 +2165,16 @@ impl AsAssocItem for ModuleDef {
         }
     }
 }
+impl AsAssocItem for DefWithBody {
+    fn as_assoc_item(self, db: &dyn HirDatabase) -> Option<AssocItem> {
+        match self {
+            DefWithBody::Function(it) => it.as_assoc_item(db),
+            DefWithBody::Const(it) => it.as_assoc_item(db),
+            DefWithBody::Static(_) | DefWithBody::Variant(_) => None,
+        }
+    }
+}
+
 fn as_assoc_item<ID, DEF, CTOR, AST>(db: &dyn HirDatabase, ctor: CTOR, id: ID) -> Option<AssocItem>
 where
     ID: Lookup<Data = AssocItemLoc<AST>>,
@@ -2560,6 +2570,14 @@ impl GenericParam {
             GenericParam::LifetimeParam(it) => it.name(db),
         }
     }
+
+    pub fn parent(self) -> GenericDef {
+        match self {
+            GenericParam::TypeParam(it) => it.id.parent().into(),
+            GenericParam::ConstParam(it) => it.id.parent().into(),
+            GenericParam::LifetimeParam(it) => it.id.parent.into(),
+        }
+    }
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]

crates/ide-assists/src/handlers/generate_delegate_methods.rs

@@ -109,7 +109,7 @@ pub(crate) fn generate_delegate_methods(acc: &mut Assists, ctx: &AssistContext<'
                 let tail_expr_finished =
                     if is_async { make::expr_await(tail_expr) } else { tail_expr };
                 let body = make::block_expr([], Some(tail_expr_finished));
-                let f = make::fn_(vis, name, type_params, params, body, ret_type, is_async)
+                let f = make::fn_(vis, name, type_params, None, params, body, ret_type, is_async)
                     .indent(ast::edit::IndentLevel(1))
                     .clone_for_update();