Use match ergonomics compatible with editions 2021 and 2024

clippy_lints/src/checked_conversions.rs

@@ -232,7 +232,7 @@ fn get_types_from_cast<'a>(
     // or `to_type::MAX as from_type`
     let call_from_cast: Option<(&Expr<'_>, &str)> = if let ExprKind::Cast(limit, from_type) = &expr.kind
         // to_type::max_value(), from_type
-        && let TyKind::Path(ref from_type_path) = &from_type.kind
+        && let TyKind::Path(from_type_path) = &from_type.kind
         && let Some(from_sym) = int_ty_to_sym(from_type_path)
     {
         Some((limit, from_sym))
@@ -245,7 +245,7 @@ fn get_types_from_cast<'a>(
         if let ExprKind::Call(from_func, [limit]) = &expr.kind
             // `from_type::from, to_type::max_value()`
             // `from_type::from`
-            && let ExprKind::Path(ref path) = &from_func.kind
+            && let ExprKind::Path(path) = &from_func.kind
             && let Some(from_sym) = get_implementing_type(path, INTS, "from")
         {
             Some((limit, from_sym))

clippy_lints/src/copy_iterator.rs

@@ -37,7 +37,7 @@ declare_lint_pass!(CopyIterator => [COPY_ITERATOR]);
 impl<'tcx> LateLintPass<'tcx> for CopyIterator {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
         if let ItemKind::Impl(Impl {
-            of_trait: Some(ref trait_ref),
+            of_trait: Some(trait_ref),
             ..
         }) = item.kind
             && let ty = cx.tcx.type_of(item.owner_id).instantiate_identity()

clippy_lints/src/derivable_impls.rs

@@ -187,7 +187,7 @@ fn check_enum<'tcx>(cx: &LateContext<'tcx>, item: &'tcx Item<'_>, func_expr: &Ex
 impl<'tcx> LateLintPass<'tcx> for DerivableImpls {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
         if let ItemKind::Impl(Impl {
-            of_trait: Some(ref trait_ref),
+            of_trait: Some(trait_ref),
             items: [child],
             self_ty,
             ..

clippy_lints/src/derive.rs

@@ -202,7 +202,7 @@ declare_lint_pass!(Derive => [
 impl<'tcx> LateLintPass<'tcx> for Derive {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
         if let ItemKind::Impl(Impl {
-            of_trait: Some(ref trait_ref),
+            of_trait: Some(trait_ref),
             ..
         }) = item.kind
         {

clippy_lints/src/disallowed_script_idents.rs

@@ -80,7 +80,7 @@ impl EarlyLintPass for DisallowedScriptIdents {
         let mut symbols: Vec<_> = symbols.iter().collect();
         symbols.sort_unstable_by_key(|k| k.1);
 
-        for (symbol, &span) in &symbols {
+        for &(symbol, &span) in &symbols {
             // Note: `symbol.as_str()` is an expensive operation, thus should not be called
             // more than once for a single symbol.
             let symbol_str = symbol.as_str();

clippy_lints/src/empty_drop.rs

@@ -36,7 +36,7 @@ declare_lint_pass!(EmptyDrop => [EMPTY_DROP]);
 impl LateLintPass<'_> for EmptyDrop {
     fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
         if let ItemKind::Impl(Impl {
-            of_trait: Some(ref trait_ref),
+            of_trait: Some(trait_ref),
             items: [child],
             ..
         }) = item.kind

clippy_lints/src/len_zero.rs

@@ -629,7 +629,7 @@ fn has_is_empty(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
                 .filter_by_name_unhygienic(is_empty)
                 .any(|item| is_is_empty(cx, item))
         }),
-        ty::Alias(ty::Projection, ref proj) => has_is_empty_impl(cx, proj.def_id),
+        ty::Alias(ty::Projection, proj) => has_is_empty_impl(cx, proj.def_id),
         ty::Adt(id, _) => has_is_empty_impl(cx, id.did()),
         ty::Array(..) | ty::Slice(..) | ty::Str => true,
         _ => false,

clippy_lints/src/lifetimes.rs

@@ -425,7 +425,7 @@ impl<'tcx> Visitor<'tcx> for RefVisitor<'_, 'tcx> {
                 self.visit_opaque_ty(opaque);
                 self.lts.truncate(len);
                 self.lts.extend(bounds.iter().filter_map(|bound| match bound {
-                    GenericArg::Lifetime(&l) => Some(l),
+                    &GenericArg::Lifetime(l) => Some(l),
                     _ => None,
                 }));
             },

clippy_lints/src/manual_async_fn.rs

@@ -169,7 +169,7 @@ fn captures_all_lifetimes(inputs: &[Ty<'_>], output_lifetimes: &[LifetimeName])
 }
 
 fn desugared_async_block<'tcx>(cx: &LateContext<'tcx>, block: &'tcx Block<'tcx>) -> Option<&'tcx Body<'tcx>> {
-    if let Some(Expr {
+    if let Some(&Expr {
         kind: ExprKind::Closure(&Closure { kind, body, .. }),
         ..
     }) = block.expr

clippy_lints/src/matches/match_like_matches.rs

@@ -148,7 +148,7 @@ fn find_bool_lit(ex: &ExprKind<'_>) -> Option<bool> {
         }) => Some(*b),
         ExprKind::Block(
             rustc_hir::Block {
-                stmts: &[],
+                stmts: [],
                 expr: Some(exp),
                 ..
             },

clippy_lints/src/matches/redundant_pattern_match.rs

@@ -319,10 +319,9 @@ fn found_good_method<'tcx>(
     node: (&PatKind<'_>, &PatKind<'_>),
 ) -> Option<(&'static str, Option<&'tcx Expr<'tcx>>)> {
     match node {
-        (
-            PatKind::TupleStruct(ref path_left, patterns_left, _),
-            PatKind::TupleStruct(ref path_right, patterns_right, _),
-        ) if patterns_left.len() == 1 && patterns_right.len() == 1 => {
+        (PatKind::TupleStruct(path_left, patterns_left, _), PatKind::TupleStruct(path_right, patterns_right, _))
+            if patterns_left.len() == 1 && patterns_right.len() == 1 =>
+        {
             if let (PatKind::Wild, PatKind::Wild) = (&patterns_left[0].kind, &patterns_right[0].kind) {
                 find_good_method_for_match(
                     cx,
@@ -350,8 +349,8 @@ fn found_good_method<'tcx>(
                 None
             }
         },
-        (PatKind::TupleStruct(ref path_left, patterns, _), PatKind::Path(ref path_right))
-        | (PatKind::Path(ref path_left), PatKind::TupleStruct(ref path_right, patterns, _))
+        (PatKind::TupleStruct(path_left, patterns, _), PatKind::Path(path_right))
+        | (PatKind::Path(path_left), PatKind::TupleStruct(path_right, patterns, _))
             if patterns.len() == 1 =>
         {
             if let PatKind::Wild = patterns[0].kind {
@@ -381,14 +380,14 @@ fn found_good_method<'tcx>(
                 None
             }
         },
-        (PatKind::TupleStruct(ref path_left, patterns, _), PatKind::Wild) if patterns.len() == 1 => {
+        (PatKind::TupleStruct(path_left, patterns, _), PatKind::Wild) if patterns.len() == 1 => {
             if let PatKind::Wild = patterns[0].kind {
                 get_good_method(cx, arms, path_left)
             } else {
                 None
             }
         },
-        (PatKind::Path(ref path_left), PatKind::Wild) => get_good_method(cx, arms, path_left),
+        (PatKind::Path(path_left), PatKind::Wild) => get_good_method(cx, arms, path_left),
         _ => None,
     }
 }

clippy_lints/src/methods/filter_map.rs

@@ -21,8 +21,8 @@ fn is_method(cx: &LateContext<'_>, expr: &Expr<'_>, method_name: Symbol) -> bool
         ExprKind::Path(QPath::TypeRelative(_, mname)) => mname.ident.name == method_name,
         ExprKind::Path(QPath::Resolved(_, segments)) => segments.segments.last().unwrap().ident.name == method_name,
         ExprKind::MethodCall(segment, _, _, _) => segment.ident.name == method_name,
-        ExprKind::Closure(&Closure { body, .. }) => {
-            let body = cx.tcx.hir().body(body);
+        ExprKind::Closure(Closure { body, .. }) => {
+            let body = cx.tcx.hir().body(*body);
             let closure_expr = peel_blocks(body.value);
             match closure_expr.kind {
                 ExprKind::MethodCall(PathSegment { ident, .. }, receiver, ..) => {

clippy_lints/src/needless_late_init.rs

@@ -347,7 +347,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessLateInit {
         if let LetStmt {
             init: None,
             pat:
-                &Pat {
+                Pat {
                     kind: PatKind::Binding(BindingMode::NONE, binding_id, _, None),
                     ..
                 },
@@ -357,7 +357,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessLateInit {
             && let Some((_, Node::Stmt(local_stmt))) = parents.next()
             && let Some((_, Node::Block(block))) = parents.next()
         {
-            check(cx, local, local_stmt, block, binding_id);
+            check(cx, local, local_stmt, block, *binding_id);
         }
     }
 }

clippy_lints/src/needless_pass_by_ref_mut.rs

@@ -183,7 +183,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByRefMut<'tcx> {
             .iter()
             .zip(fn_sig.inputs())
             .zip(body.params)
-            .filter(|((&input, &ty), arg)| !should_skip(cx, input, ty, arg))
+            .filter(|&((&input, &ty), arg)| !should_skip(cx, input, ty, arg))
             .peekable();
         if it.peek().is_none() {
             return;

clippy_lints/src/partialeq_ne_impl.rs

@@ -34,7 +34,7 @@ declare_lint_pass!(PartialEqNeImpl => [PARTIALEQ_NE_IMPL]);
 impl<'tcx> LateLintPass<'tcx> for PartialEqNeImpl {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
         if let ItemKind::Impl(Impl {
-            of_trait: Some(ref trait_ref),
+            of_trait: Some(trait_ref),
             items: impl_items,
             ..
         }) = item.kind

clippy_lints/src/question_mark.rs

@@ -93,7 +93,7 @@ enum IfBlockType<'hir> {
 
 fn find_let_else_ret_expression<'hir>(block: &'hir Block<'hir>) -> Option<&'hir Expr<'hir>> {
     if let Block {
-        stmts: &[],
+        stmts: [],
         expr: Some(els),
         ..
     } = block

clippy_lints/src/ref_option_ref.rs

@@ -39,7 +39,7 @@ impl<'tcx> LateLintPass<'tcx> for RefOptionRef {
     fn check_ty(&mut self, cx: &LateContext<'tcx>, ty: &'tcx Ty<'tcx>) {
         if let TyKind::Ref(_, ref mut_ty) = ty.kind
             && mut_ty.mutbl == Mutability::Not
-            && let TyKind::Path(ref qpath) = &mut_ty.ty.kind
+            && let TyKind::Path(qpath) = &mut_ty.ty.kind
             && let last = last_path_segment(qpath)
             && let Some(def_id) = last.res.opt_def_id()
             && cx.tcx.is_diagnostic_item(sym::Option, def_id)

clippy_lints/src/returns.rs

@@ -347,7 +347,7 @@ fn check_final_expr<'tcx>(
     let peeled_drop_expr = expr.peel_drop_temps();
     match &peeled_drop_expr.kind {
         // simple return is always "bad"
-        ExprKind::Ret(ref inner) => {
+        ExprKind::Ret(inner) => {
             // check if expr return nothing
             let ret_span = if inner.is_none() && replacement == RetReplacement::Empty {
                 extend_span_to_previous_non_ws(cx, peeled_drop_expr.span)

clippy_lints/src/serde_api.rs

@@ -26,7 +26,7 @@ declare_lint_pass!(SerdeApi => [SERDE_API_MISUSE]);
 impl<'tcx> LateLintPass<'tcx> for SerdeApi {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
         if let ItemKind::Impl(Impl {
-            of_trait: Some(ref trait_ref),
+            of_trait: Some(trait_ref),
             items,
             ..
         }) = item.kind

clippy_lints/src/single_component_path_imports.rs

@@ -174,7 +174,7 @@ impl SingleComponentPathImports {
         }
 
         match &item.kind {
-            ItemKind::Mod(_, ModKind::Loaded(ref items, ..)) => {
+            ItemKind::Mod(_, ModKind::Loaded(items, ..)) => {
                 self.check_mod(items);
             },
             ItemKind::MacroDef(MacroDef { macro_rules: true, .. }) => {

clippy_lints/src/suspicious_operation_groupings.rs

@@ -334,7 +334,7 @@ fn strip_non_ident_wrappers(expr: &Expr) -> &Expr {
     let mut output = expr;
     loop {
         output = match &output.kind {
-            ExprKind::Paren(ref inner) | ExprKind::Unary(_, ref inner) => inner,
+            ExprKind::Paren(inner) | ExprKind::Unary(_, inner) => inner,
             _ => {
                 return output;
             },
@@ -348,13 +348,13 @@ fn extract_related_binops(kind: &ExprKind) -> Option<Vec<BinaryOp<'_>>> {
 
 fn if_statement_binops(kind: &ExprKind) -> Option<Vec<BinaryOp<'_>>> {
     match kind {
-        ExprKind::If(ref condition, _, _) => chained_binops(&condition.kind),
-        ExprKind::Paren(ref e) => if_statement_binops(&e.kind),
-        ExprKind::Block(ref block, _) => {
+        ExprKind::If(condition, _, _) => chained_binops(&condition.kind),
+        ExprKind::Paren(e) => if_statement_binops(&e.kind),
+        ExprKind::Block(block, _) => {
             let mut output = None;
             for stmt in &block.stmts {
-                match stmt.kind {
-                    StmtKind::Expr(ref e) | StmtKind::Semi(ref e) => {
+                match &stmt.kind {
+                    StmtKind::Expr(e) | StmtKind::Semi(e) => {
                         output = append_opt_vecs(output, if_statement_binops(&e.kind));
                     },
                     _ => {},
@@ -383,24 +383,22 @@ fn append_opt_vecs<A>(target_opt: Option<Vec<A>>, source_opt: Option<Vec<A>>) ->
 fn chained_binops(kind: &ExprKind) -> Option<Vec<BinaryOp<'_>>> {
     match kind {
         ExprKind::Binary(_, left_outer, right_outer) => chained_binops_helper(left_outer, right_outer),
-        ExprKind::Paren(ref e) | ExprKind::Unary(_, ref e) => chained_binops(&e.kind),
+        ExprKind::Paren(e) | ExprKind::Unary(_, e) => chained_binops(&e.kind),
         _ => None,
     }
 }
 
 fn chained_binops_helper<'expr>(left_outer: &'expr Expr, right_outer: &'expr Expr) -> Option<Vec<BinaryOp<'expr>>> {
     match (&left_outer.kind, &right_outer.kind) {
         (
-            ExprKind::Paren(ref left_e) | ExprKind::Unary(_, ref left_e),
-            ExprKind::Paren(ref right_e) | ExprKind::Unary(_, ref right_e),
+            ExprKind::Paren(left_e) | ExprKind::Unary(_, left_e),
+            ExprKind::Paren(right_e) | ExprKind::Unary(_, right_e),
         ) => chained_binops_helper(left_e, right_e),
-        (ExprKind::Paren(ref left_e) | ExprKind::Unary(_, ref left_e), _) => chained_binops_helper(left_e, right_outer),
-        (_, ExprKind::Paren(ref right_e) | ExprKind::Unary(_, ref right_e)) => {
-            chained_binops_helper(left_outer, right_e)
-        },
+        (ExprKind::Paren(left_e) | ExprKind::Unary(_, left_e), _) => chained_binops_helper(left_e, right_outer),
+        (_, ExprKind::Paren(right_e) | ExprKind::Unary(_, right_e)) => chained_binops_helper(left_outer, right_e),
         (
-            ExprKind::Binary(Spanned { node: left_op, .. }, ref left_left, ref left_right),
-            ExprKind::Binary(Spanned { node: right_op, .. }, ref right_left, ref right_right),
+            ExprKind::Binary(Spanned { node: left_op, .. }, left_left, left_right),
+            ExprKind::Binary(Spanned { node: right_op, .. }, right_left, right_right),
         ) => match (
             chained_binops_helper(left_left, left_right),
             chained_binops_helper(right_left, right_right),

clippy_lints/src/swap.rs

@@ -392,7 +392,7 @@ impl<'tcx> IndexBinding<'_, 'tcx> {
         for stmt in self.block.stmts {
             match stmt.kind {
                 StmtKind::Expr(expr) | StmtKind::Semi(expr) => v.visit_expr(expr),
-                StmtKind::Let(LetStmt { ref init, .. }) => {
+                StmtKind::Let(LetStmt { init, .. }) => {
                     if let Some(init) = init.as_ref() {
                         v.visit_expr(init);
                     }

clippy_lints/src/trait_bounds.rs

@@ -124,7 +124,7 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
         let mut self_bounds_map = FxHashMap::default();
 
         for predicate in item.generics.predicates {
-            if let WherePredicate::BoundPredicate(ref bound_predicate) = predicate
+            if let WherePredicate::BoundPredicate(bound_predicate) = predicate
                 && bound_predicate.origin != PredicateOrigin::ImplTrait
                 && !bound_predicate.span.from_expansion()
                 && let TyKind::Path(QPath::Resolved(_, Path { segments, .. })) = bound_predicate.bounded_ty.kind
@@ -268,7 +268,7 @@ impl TraitBounds {
         let mut map: UnhashMap<SpanlessTy<'_, '_>, Vec<&GenericBound<'_>>> = UnhashMap::default();
         let mut applicability = Applicability::MaybeIncorrect;
         for bound in generics.predicates {
-            if let WherePredicate::BoundPredicate(ref p) = bound
+            if let WherePredicate::BoundPredicate(p) = bound
                 && p.origin != PredicateOrigin::ImplTrait
                 && p.bounds.len() as u64 <= self.max_trait_bounds
                 && !p.span.from_expansion()

clippy_lints/src/undocumented_unsafe_blocks.rs

@@ -295,7 +295,7 @@ fn expr_has_unnecessary_safety_comment<'tcx>(
     if cx.tcx.hir().parent_iter(expr.hir_id).any(|(_, ref node)| {
         matches!(
             node,
-            Node::Block(&Block {
+            Node::Block(Block {
                 rules: BlockCheckMode::UnsafeBlock(UnsafeSource::UserProvided),
                 ..
             }),

clippy_lints/src/unit_types/let_unit_value.rs

@@ -194,7 +194,7 @@ fn needs_inferred_result_ty(
     let (id, receiver, args) = match e.kind {
         ExprKind::Call(
             Expr {
-                kind: ExprKind::Path(ref path),
+                kind: ExprKind::Path(path),
                 hir_id,
                 ..
             },

clippy_lints/src/unit_types/unit_arg.rs

@@ -149,7 +149,7 @@ fn is_empty_block(expr: &Expr<'_>) -> bool {
         expr.kind,
         ExprKind::Block(
             Block {
-                stmts: &[],
+                stmts: [],
                 expr: None,
                 ..
             },

clippy_lints/src/unused_io_amount.rs

@@ -244,7 +244,7 @@ fn unpack_call_chain<'a>(mut expr: &'a hir::Expr<'a>) -> &'a hir::Expr<'a> {
 }
 
 fn unpack_try<'a>(mut expr: &'a hir::Expr<'a>) -> &'a hir::Expr<'a> {
-    while let ExprKind::Call(func, [ref arg_0]) = expr.kind
+    while let ExprKind::Call(func, [arg_0]) = expr.kind
         && matches!(
             func.kind,
             ExprKind::Path(hir::QPath::LangItem(hir::LangItem::TryTraitBranch, ..))
@@ -266,7 +266,7 @@ fn unpack_match<'a>(mut expr: &'a hir::Expr<'a>) -> &'a hir::Expr<'a> {
 /// waited on.  Otherwise return None.
 fn unpack_await<'a>(expr: &'a hir::Expr<'a>) -> &'a hir::Expr<'a> {
     if let ExprKind::Match(expr, _, hir::MatchSource::AwaitDesugar) = expr.kind {
-        if let ExprKind::Call(func, [ref arg_0]) = expr.kind {
+        if let ExprKind::Call(func, [arg_0]) = expr.kind {
             if matches!(
                 func.kind,
                 ExprKind::Path(hir::QPath::LangItem(hir::LangItem::IntoFutureIntoFuture, ..))

clippy_lints/src/utils/author.rs

@@ -396,7 +396,7 @@ impl<'a, 'tcx> PrintVisitor<'a, 'tcx> {
                 self.pat(field!(let_expr.pat));
                 // Does what ExprKind::Cast does, only adds a clause for the type
                 // if it's a path
-                if let Some(TyKind::Path(ref qpath)) = let_expr.value.ty.as_ref().map(|ty| &ty.kind) {
+                if let Some(TyKind::Path(qpath)) = let_expr.value.ty.as_ref().map(|ty| &ty.kind) {
                     bind!(self, qpath);
                     chain!(self, "let TyKind::Path(ref {qpath}) = {let_expr}.ty.kind");
                     self.qpath(qpath);

clippy_lints/src/utils/internal_lints/collapsible_calls.rs

@@ -79,7 +79,7 @@ impl<'tcx> LateLintPass<'tcx> for CollapsibleCalls {
 
         if let ExprKind::Call(func, [call_cx, call_lint, call_sp, call_msg, call_f]) = expr.kind
             && is_expr_path_def_path(cx, func, &["clippy_utils", "diagnostics", "span_lint_and_then"])
-            && let ExprKind::Closure(&Closure { body, .. }) = &call_f.kind
+            && let ExprKind::Closure(&Closure { body, .. }) = call_f.kind
             && let body = cx.tcx.hir().body(body)
             && let only_expr = peel_blocks_with_stmt(body.value)
             && let ExprKind::MethodCall(ps, recv, span_call_args, _) = &only_expr.kind