diff --git a/lib/codegen/meta/src/cdsl/settings.rs b/lib/codegen/meta/src/cdsl/settings.rs
index 253f7680d6..805dfd2a7a 100644
--- a/lib/codegen/meta/src/cdsl/settings.rs
+++ b/lib/codegen/meta/src/cdsl/settings.rs
@@ -101,7 +101,8 @@ impl Preset {
             let mask = setting.byte_mask();
             let val = setting.byte_for_value(true);
             assert!((val & !mask) == 0);
-            let (l_mask, l_val) = layout.get_mut(setting.byte_offset as usize).unwrap();
+            let (ref mut l_mask, ref mut l_val) =
+                *layout.get_mut(setting.byte_offset as usize).unwrap();
             *l_mask |= mask;
             *l_val = (*l_val & !mask) | val;
         }
@@ -186,15 +187,15 @@ impl<'a> Into<PredicateNode> for (BoolSettingIndex, &'a SettingGroup) {
 
 impl PredicateNode {
     fn render(&self, group: &SettingGroup) -> String {
-        match self {
+        match *self {
             PredicateNode::OwnedBool(bool_setting_index) => format!(
                 "{}.{}()",
                 group.name, group.settings[bool_setting_index.0].name
             ),
-            PredicateNode::SharedBool(group_name, bool_name) => {
+            PredicateNode::SharedBool(ref group_name, ref bool_name) => {
                 format!("{}.{}()", group_name, bool_name)
             }
-            PredicateNode::And(lhs, rhs) => {
+            PredicateNode::And(ref lhs, ref rhs) => {
                 format!("{} && {}", lhs.render(group), rhs.render(group))
             }
         }
diff --git a/lib/codegen/meta/src/gen_settings.rs b/lib/codegen/meta/src/gen_settings.rs
index cd50a57f88..93fddce210 100644
--- a/lib/codegen/meta/src/gen_settings.rs
+++ b/lib/codegen/meta/src/gen_settings.rs
@@ -224,7 +224,7 @@ enum SettingOrPreset<'a> {
 
 impl<'a> SettingOrPreset<'a> {
     fn name(&self) -> &str {
-        match self {
+        match *self {
             SettingOrPreset::Setting(s) => s.name,
             SettingOrPreset::Preset(p) => p.name,
         }
@@ -248,14 +248,14 @@ fn gen_descriptors(group: &SettingGroup, fmt: &mut Formatter) {
             fmt.indent(|fmt| {
                 fmt.line(&format!("name: \"{}\",", setting.name));
                 fmt.line(&format!("offset: {},", setting.byte_offset));
-                match &setting.specific {
+                match setting.specific {
                     SpecificSetting::Bool(BoolSetting { bit_offset, .. }) => {
                         fmt.line(&format!(
                             "detail: detail::Detail::Bool {{ bit: {} }},",
                             bit_offset
                         ));
                     }
-                    SpecificSetting::Enum(values) => {
+                    SpecificSetting::Enum(ref values) => {
                         let offset = enum_table.add(values);
                         fmt.line(&format!(
                             "detail: detail::Detail::Enum {{ last: {}, enumerators: {} }},",
@@ -322,7 +322,7 @@ fn gen_descriptors(group: &SettingGroup, fmt: &mut Formatter) {
     ));
     fmt.indent(|fmt| {
         for h in &hash_table {
-            match h {
+            match *h {
                 Some(setting_or_preset) => fmt.line(&format!(
                     "{},",
                     &descriptor_index_map
diff --git a/lib/codegen/meta/src/srcgen.rs b/lib/codegen/meta/src/srcgen.rs
index 36270b9c70..295567de80 100644
--- a/lib/codegen/meta/src/srcgen.rs
+++ b/lib/codegen/meta/src/srcgen.rs
@@ -122,7 +122,7 @@ impl Formatter {
     pub fn add_match(&mut self, m: Match) {
         self.line(&format!("match {} {{", m.expr));
         self.indent(|fmt| {
-            for ((fields, body), names) in m.arms.iter() {
+            for (&(ref fields, ref body), ref names) in m.arms.iter() {
                 // name { fields } | name { fields } => { body }
                 let conditions: Vec<String> = names
                     .iter()
@@ -252,7 +252,7 @@ mod srcgen_tests {
     use super::Formatter;
     use super::Match;
 
-    fn from_raw_string(s: impl Into<String>) -> Vec<String> {
+    fn from_raw_string<S: Into<String>>(s: S) -> Vec<String> {
         s.into()
             .trim()
             .split("\n")