chore: bump maximum clang tested to 20 (#5692)

include/pybind11/cast.h

@@ -817,7 +817,9 @@ protected:
     cast_impl(T &&src, return_value_policy policy, handle parent, index_sequence<Is...>) {
         PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(src, policy, parent);
         PYBIND11_WORKAROUND_INCORRECT_GCC_UNUSED_BUT_SET_PARAMETER(policy, parent);
+
         std::array<object, size> entries{{reinterpret_steal<object>(
+            // NOLINTNEXTLINE(bugprone-use-after-move)
             make_caster<Ts>::cast(std::get<Is>(std::forward<T>(src)), policy, parent))...}};
         for (const auto &entry : entries) {
             if (!entry) {

include/pybind11/chrono.h

@@ -63,6 +63,9 @@ public:
     get_duration(const std::chrono::duration<rep, period> &src) {
         return src;
     }
+    static const std::chrono::duration<rep, period> &
+    get_duration(const std::chrono::duration<rep, period> &&)
+        = delete;
 
     // If this is a time_point get the time_since_epoch
     template <typename Clock>

include/pybind11/detail/init.h

@@ -273,7 +273,8 @@ struct constructor {
     static void execute(Class &cl, const Extra &...extra) {
         cl.def(
             "__init__",
-            [](value_and_holder &v_h, Args... args) {
+            [](value_and_holder &v_h,
+               Args... args) { // NOLINT(performance-unnecessary-value-param)
                 v_h.value_ptr() = construct_or_initialize<Cpp<Class>>(std::forward<Args>(args)...);
             },
             is_new_style_constructor(),

include/pybind11/detail/struct_smart_holder.h

@@ -340,7 +340,7 @@ struct smart_holder {
     }
 
     template <typename T>
-    static smart_holder from_shared_ptr(std::shared_ptr<T> shd_ptr) {
+    static smart_holder from_shared_ptr(const std::shared_ptr<T> &shd_ptr) {
         smart_holder hld;
         hld.vptr = std::static_pointer_cast<void>(shd_ptr);
         hld.vptr_is_external_shared_ptr = true;

include/pybind11/functional.h

@@ -48,7 +48,7 @@ struct func_wrapper_base {
 template <typename Return, typename... Args>
 struct func_wrapper : func_wrapper_base {
     using func_wrapper_base::func_wrapper_base;
-    Return operator()(Args... args) const {
+    Return operator()(Args... args) const { // NOLINT(performance-unnecessary-value-param)
         gil_scoped_acquire acq;
         // casts the returned object as a rvalue to the return type
         return hfunc.f(std::forward<Args>(args)...).template cast<Return>();

include/pybind11/pybind11.h

@@ -3043,6 +3043,7 @@ template <typename Access,
           typename Sentinel,
           typename ValueType,
           typename... Extra>
+// NOLINTNEXTLINE(performance-unnecessary-value-param)
 iterator make_iterator_impl(Iterator first, Sentinel last, Extra &&...extra) {
     using state = detail::iterator_state<Access, Policy, Iterator, Sentinel, ValueType, Extra...>;
     // TODO: state captures only the types of Extra, not the values
@@ -3082,6 +3083,7 @@ template <return_value_policy Policy = return_value_policy::reference_internal,
           typename Sentinel,
           typename ValueType = typename detail::iterator_access<Iterator>::result_type,
           typename... Extra>
+// NOLINTNEXTLINE(performance-unnecessary-value-param)
 typing::Iterator<ValueType> make_iterator(Iterator first, Sentinel last, Extra &&...extra) {
     return detail::make_iterator_impl<detail::iterator_access<Iterator>,
                                       Policy,

include/pybind11/pytypes.h

@@ -81,7 +81,9 @@ using is_pyobject = std::is_base_of<pyobject_tag, remove_reference_t<T>>;
 \endrst */
 template <typename Derived>
 class object_api : public pyobject_tag {
+    object_api() = default;
     const Derived &derived() const { return static_cast<const Derived &>(*this); }
+    friend Derived;
 
 public:
     /** \rst
@@ -276,7 +278,7 @@ public:
         inc_ref_counter(1);
 #endif
 #ifdef PYBIND11_ASSERT_GIL_HELD_INCREF_DECREF
-        if (m_ptr != nullptr && !PyGILState_Check()) {
+        if (m_ptr != nullptr && PyGILState_Check() == 0) {
             throw_gilstate_error("pybind11::handle::inc_ref()");
         }
 #endif
@@ -291,7 +293,7 @@ public:
     \endrst */
     const handle &dec_ref() const & {
 #ifdef PYBIND11_ASSERT_GIL_HELD_INCREF_DECREF
-        if (m_ptr != nullptr && !PyGILState_Check()) {
+        if (m_ptr != nullptr && PyGILState_Check() == 0) {
             throw_gilstate_error("pybind11::handle::dec_ref()");
         }
 #endif

include/pybind11/stl.h

@@ -178,7 +178,7 @@ private:
         return true;
     }
 
-    bool convert_anyset(anyset s, bool convert) {
+    bool convert_anyset(const anyset &s, bool convert) {
         value.clear();
         reserve_maybe(s, &value);
         return convert_iterable(s, convert);