diff --git a/crates/ide-assists/src/handlers/generate_function.rs b/crates/ide-assists/src/handlers/generate_function.rs
index 57f198748c..da9b0cda5b 100644
--- a/crates/ide-assists/src/handlers/generate_function.rs
+++ b/crates/ide-assists/src/handlers/generate_function.rs
@@ -514,7 +514,7 @@ fn fn_args(
 ///     vec!["foo_1".into(), "foo_2".into(), "bar_1".into(), "baz".into(), "bar_2".into()];
 /// assert_eq!(names, expected);
 /// ```
-fn deduplicate_arg_names(arg_names: &mut Vec<String>) {
+fn deduplicate_arg_names(arg_names: &mut [String]) {
     let mut arg_name_counts = FxHashMap::default();
     for name in arg_names.iter() {
         *arg_name_counts.entry(name).or_insert(0) += 1;
diff --git a/crates/ide-assists/src/utils/gen_trait_fn_body.rs b/crates/ide-assists/src/utils/gen_trait_fn_body.rs
index f32e5ce97d..d4abb51259 100644
--- a/crates/ide-assists/src/utils/gen_trait_fn_body.rs
+++ b/crates/ide-assists/src/utils/gen_trait_fn_body.rs
@@ -419,7 +419,7 @@ fn gen_partial_eq(adt: &ast::Adt, func: &ast::Fn) -> Option<()> {
         make::ext::path_from_idents(["Self", &variant.name()?.to_string()])
     }
 
-    fn gen_tuple_field(field_name: &String) -> ast::Pat {
+    fn gen_tuple_field(field_name: &str) -> ast::Pat {
         ast::Pat::IdentPat(make::ident_pat(false, false, make::name(field_name)))
     }
 
diff --git a/crates/test-utils/src/assert_linear.rs b/crates/test-utils/src/assert_linear.rs
index d6acdde383..15c30c52a5 100644
--- a/crates/test-utils/src/assert_linear.rs
+++ b/crates/test-utils/src/assert_linear.rs
@@ -100,7 +100,7 @@ impl Round {
 
         self.linear = rmse < 0.05 && max_error < 0.1 && a > -0.1;
 
-        fn normalize(xs: &mut Vec<f64>) {
+        fn normalize(xs: &mut [f64]) {
             let max = xs.iter().copied().max_by(|a, b| a.partial_cmp(b).unwrap()).unwrap();
             xs.iter_mut().for_each(|it| *it /= max);
         }