a few fixes due to update of clang-tidy to 21.1.4

.clang-tidy

@@ -10,19 +10,20 @@ Checks: >-
   -cppcoreguidelines-macro-to-enum,
   -cppcoreguidelines-pro-bounds-constant-array-index,
   -cppcoreguidelines-pro-bounds-pointer-arithmetic,
+  -fuchsia-default-arguments-calls,
   -fuchsia-default-arguments-declarations,
   -fuchsia-overloaded-operator,
-  -fuchsia-default-arguments-calls,
-  -llvmlibc-implementation-in-namespace,
-  -modernize-use-constraints,
   -fuchsia-trailing-return,
   -llvmlibc-callee-namespace,
+  -llvmlibc-implementation-in-namespace,
   -llvmlibc-inline-function-decl,
   -llvmlibc-restrict-system-libc-headers,
   -modernize-macro-to-enum,
+  -modernize-use-constraints,
   -readability-function-cognitive-complexity,
   -readability-identifier-length,
   -readability-magic-numbers,
+  -readability-use-concise-preprocessor-directives,
 HeaderFilterRegex: '.*unordered_dense\.h'
 CheckOptions:
   cppcoreguidelines-avoid-do-while.IgnoreMacros: 'true'

include/ankerl/unordered_dense.h

@@ -1802,7 +1802,7 @@ public:
             bucket_idx = next(bucket_idx);
         }
 
-        do_erase(bucket_idx, [](value_type const& /*unused*/) {
+        do_erase(bucket_idx, [](value_type const& /*unused*/) -> void {
         });
         return begin() + static_cast<difference_type>(value_idx_to_remove);
     }
@@ -1817,7 +1817,7 @@ public:
         }
 
         auto tmp = std::optional<value_type>{};
-        do_erase(bucket_idx, [&tmp](value_type&& val) {
+        do_erase(bucket_idx, [&tmp](value_type&& val) -> void {
             tmp = std::move(val);
         });
         return std::move(tmp).value();
@@ -1858,13 +1858,13 @@ public:
     }
 
     auto erase(Key const& key) -> std::size_t {
-        return do_erase_key(key, [](value_type const& /*unused*/) {
+        return do_erase_key(key, [](value_type const& /*unused*/) -> void {
         });
     }
 
     auto extract(Key const& key) -> std::optional<value_type> {
         auto tmp = std::optional<value_type>{};
-        do_erase_key(key, [&tmp](value_type&& val) {
+        do_erase_key(key, [&tmp](value_type&& val) -> void {
             tmp = std::move(val);
         });
         return tmp;
@@ -1872,14 +1872,14 @@ public:
 
     template <class K, class H = Hash, class KE = KeyEqual, std::enable_if_t<is_transparent_v<H, KE>, bool> = true>
     auto erase(K&& key) -> std::size_t {
-        return do_erase_key(std::forward<K>(key), [](value_type const& /*unused*/) {
+        return do_erase_key(std::forward<K>(key), [](value_type const& /*unused*/) -> void {
         });
     }
 
     template <class K, class H = Hash, class KE = KeyEqual, std::enable_if_t<is_transparent_v<H, KE>, bool> = true>
     auto extract(K&& key) -> std::optional<value_type> {
         auto tmp = std::optional<value_type>{};
-        do_erase_key(std::forward<K>(key), [&tmp](value_type&& val) {
+        do_erase_key(std::forward<K>(key), [&tmp](value_type&& val) -> void {
             tmp = std::move(val);
         });
         return tmp;