diff --git a/crates/hir-expand/src/attrs.rs b/crates/hir-expand/src/attrs.rs
index 30d38299d9..b0b2501ce9 100644
--- a/crates/hir-expand/src/attrs.rs
+++ b/crates/hir-expand/src/attrs.rs
@@ -235,7 +235,7 @@ impl Attr {
         let (path, input) = tt.split_at(path_end);
         let path = Interned::new(ModPath::from_tt(db, path)?);
 
-        let input = match input.get(0) {
+        let input = match input.first() {
             Some(tt::TokenTree::Subtree(tree)) => {
                 Some(Interned::new(AttrInput::TokenTree(Box::new(tree.clone()))))
             }
diff --git a/crates/hir-expand/src/mod_path.rs b/crates/hir-expand/src/mod_path.rs
index 0eb1fc1eb5..dd41bcaee2 100644
--- a/crates/hir-expand/src/mod_path.rs
+++ b/crates/hir-expand/src/mod_path.rs
@@ -232,7 +232,7 @@ fn convert_path(
         ast::PathSegmentKind::SuperKw => {
             let mut deg = 1;
             let mut next_segment = None;
-            while let Some(segment) = segments.next() {
+            for segment in segments.by_ref() {
                 match segment.kind()? {
                     ast::PathSegmentKind::SuperKw => deg += 1,
                     ast::PathSegmentKind::Name(name) => {
diff --git a/crates/hir-ty/src/diagnostics/match_check/pat_analysis.rs b/crates/hir-ty/src/diagnostics/match_check/pat_analysis.rs
index cd67ca5993..e2d8c97cd9 100644
--- a/crates/hir-ty/src/diagnostics/match_check/pat_analysis.rs
+++ b/crates/hir-ty/src/diagnostics/match_check/pat_analysis.rs
@@ -237,7 +237,7 @@ impl<'p> MatchCheckCtx<'p> {
                 ctor = Or;
                 // Collect here because `Arena::alloc_extend` panics on reentrancy.
                 let subpats: SmallVec<[_; 2]> =
-                    pats.into_iter().map(|pat| self.lower_pat(pat)).collect();
+                    pats.iter().map(|pat| self.lower_pat(pat)).collect();
                 fields = self.pattern_arena.alloc_extend(subpats);
             }
         }
diff --git a/crates/hir-ty/src/mir/eval.rs b/crates/hir-ty/src/mir/eval.rs
index 885360d05f..b821942f21 100644
--- a/crates/hir-ty/src/mir/eval.rs
+++ b/crates/hir-ty/src/mir/eval.rs
@@ -1715,7 +1715,7 @@ impl Evaluator<'_> {
         let v: Cow<'_, [u8]> = if size != v.len() {
             // Handle self enum
             if size == 16 && v.len() < 16 {
-                Cow::Owned(pad16(&v, false).to_vec())
+                Cow::Owned(pad16(v, false).to_vec())
             } else if size < 16 && v.len() == 16 {
                 Cow::Borrowed(&v[0..size])
             } else {
diff --git a/crates/hir/src/attrs.rs b/crates/hir/src/attrs.rs
index fc0a196df7..f2b9db669e 100644
--- a/crates/hir/src/attrs.rs
+++ b/crates/hir/src/attrs.rs
@@ -311,7 +311,7 @@ fn modpath_from_str(link: &str) -> Option<ModPath> {
             "self" => PathKind::Super(0),
             "super" => {
                 let mut deg = 1;
-                while let Some(segment) = parts.next() {
+                for segment in parts.by_ref() {
                     if segment == "super" {
                         deg += 1;
                     } else {