Replace C-style casts to static_cast and reinterpret_cast (#5930)

* Replace C-style casts to static_cast and reinterpret_cast

Signed-off-by: cyy <cyyever@outlook.com>

* style: pre-commit fixes

---------

Signed-off-by: cyy <cyyever@outlook.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: cyyever

include/pybind11/attr.h

@@ -373,7 +373,7 @@ struct type_record {
                           + (base_has_unique_ptr_holder ? "does not" : "does"));
         }
 
-        bases.append((PyObject *) base_info->type);
+        bases.append(reinterpret_cast<PyObject *>(base_info->type));
 
 #ifdef PYBIND11_BACKWARD_COMPATIBILITY_TP_DICTOFFSET
         dynamic_attr |= base_info->type->tp_dictoffset != 0;
@@ -721,7 +721,9 @@ template <typename... Extra,
           size_t self = constexpr_sum(std::is_same<is_method, Extra>::value...)>
 constexpr bool expected_num_args(size_t nargs, bool has_args, bool has_kwargs) {
     PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(nargs, has_args, has_kwargs);
-    return named == 0 || (self + named + size_t(has_args) + size_t(has_kwargs)) == nargs;
+    return named == 0
+           || (self + named + static_cast<size_t>(has_args) + static_cast<size_t>(has_kwargs))
+                  == nargs;
 }
 
 PYBIND11_NAMESPACE_END(detail)

include/pybind11/buffer_info.h

@@ -66,10 +66,11 @@ struct buffer_info {
                 bool readonly = false)
         : ptr(ptr), itemsize(itemsize), size(1), format(format), ndim(ndim),
           shape(std::move(shape_in)), strides(std::move(strides_in)), readonly(readonly) {
-        if (ndim != (ssize_t) shape.size() || ndim != (ssize_t) strides.size()) {
+        if (ndim != static_cast<ssize_t>(shape.size())
+            || ndim != static_cast<ssize_t>(strides.size())) {
             pybind11_fail("buffer_info: ndim doesn't match shape and/or strides length");
         }
-        for (size_t i = 0; i < (size_t) ndim; ++i) {
+        for (size_t i = 0; i < static_cast<size_t>(ndim); ++i) {
             size *= shape[i];
         }
     }
@@ -195,7 +196,7 @@ struct compare_buffer_info {
 template <typename T>
 struct compare_buffer_info<T, detail::enable_if_t<std::is_integral<T>::value>> {
     static bool compare(const buffer_info &b) {
-        return (size_t) b.itemsize == sizeof(T)
+        return static_cast<size_t>(b.itemsize) == sizeof(T)
                && (b.format == format_descriptor<T>::value
                    || ((sizeof(T) == sizeof(long))
                        && b.format == (std::is_unsigned<T>::value ? "L" : "l"))

include/pybind11/cast.h

@@ -394,7 +394,8 @@ class type_caster<void> : public type_caster<void_type> {
         }
 
         /* Check if this is a C++ type */
-        const auto &bases = all_type_info((PyTypeObject *) type::handle_of(h).ptr());
+        const auto &bases
+            = all_type_info(reinterpret_cast<PyTypeObject *>(type::handle_of(h).ptr()));
         if (bases.size() == 1) { // Only allowing loading from a single-value type
             value = values_and_holders(reinterpret_cast<instance *>(h.ptr())).begin()->value_ptr();
             return true;
@@ -541,7 +542,7 @@ struct string_caster {
 
         const auto *buffer
             = reinterpret_cast<const CharT *>(PYBIND11_BYTES_AS_STRING(utfNbytes.ptr()));
-        size_t length = (size_t) PYBIND11_BYTES_SIZE(utfNbytes.ptr()) / sizeof(CharT);
+        size_t length = static_cast<size_t>(PYBIND11_BYTES_SIZE(utfNbytes.ptr())) / sizeof(CharT);
         // Skip BOM for UTF-16/32
         if (UTF_N > 8) {
             buffer++;

include/pybind11/detail/argument_vector.h

@@ -231,7 +231,7 @@ struct args_convert_vector {
             new (&m_repr.hvector) typename repr_type::heap_vector(count, value);
         } else {
             auto &inline_arr = m_repr.iarray;
-            inline_arr.arr.fill(value ? std::size_t(-1) : 0);
+            inline_arr.arr.fill(value ? static_cast<std::size_t>(-1) : 0);
             inline_arr.size = static_cast<decltype(inline_arr.size)>(count);
         }
     }
@@ -273,9 +273,9 @@ struct args_convert_vector {
                 assert(wbi.word < kWords);
                 assert(wbi.bit < kBitsPerWord);
                 if (b) {
-                    ha.arr[wbi.word] |= (std::size_t(1) << wbi.bit);
+                    ha.arr[wbi.word] |= (static_cast<std::size_t>(1) << wbi.bit);
                 } else {
-                    ha.arr[wbi.word] &= ~(std::size_t(1) << wbi.bit);
+                    ha.arr[wbi.word] &= ~(static_cast<std::size_t>(1) << wbi.bit);
                 }
                 assert(operator[](ha.size - 1) == b);
             }
@@ -300,7 +300,7 @@ struct args_convert_vector {
         const auto wbi = word_and_bit_index(idx);
         assert(wbi.word < kWords);
         assert(wbi.bit < kBitsPerWord);
-        return m_repr.iarray.arr[wbi.word] & (std::size_t(1) << wbi.bit);
+        return m_repr.iarray.arr[wbi.word] & (static_cast<std::size_t>(1) << wbi.bit);
     }
 
     PYBIND11_NOINLINE void move_to_heap_vector_with_reserved_size(std::size_t reserved_size) {

include/pybind11/detail/class.h

@@ -71,7 +71,7 @@ inline PyTypeObject *make_static_property_type() {
        issue no Python C API calls which could potentially invoke the
        garbage collector (the GC will call type_traverse(), which will in
        turn find the newly constructed type in an invalid state) */
-    auto *heap_type = (PyHeapTypeObject *) PyType_Type.tp_alloc(&PyType_Type, 0);
+    auto *heap_type = reinterpret_cast<PyHeapTypeObject *>(PyType_Type.tp_alloc(&PyType_Type, 0));
     if (!heap_type) {
         pybind11_fail("make_static_property_type(): error allocating type!");
     }
@@ -98,7 +98,7 @@ inline PyTypeObject *make_static_property_type() {
         pybind11_fail("make_static_property_type(): failure in PyType_Ready()!");
     }
 
-    setattr((PyObject *) type, "__module__", str(PYBIND11_DUMMY_MODULE_NAME));
+    setattr(reinterpret_cast<PyObject *>(type), "__module__", str(PYBIND11_DUMMY_MODULE_NAME));
     PYBIND11_SET_OLDPY_QUALNAME(type, name_obj);
 
     return type;
@@ -265,7 +265,7 @@ inline PyTypeObject *make_default_metaclass() {
        issue no Python C API calls which could potentially invoke the
        garbage collector (the GC will call type_traverse(), which will in
        turn find the newly constructed type in an invalid state) */
-    auto *heap_type = (PyHeapTypeObject *) PyType_Type.tp_alloc(&PyType_Type, 0);
+    auto *heap_type = reinterpret_cast<PyHeapTypeObject *>(PyType_Type.tp_alloc(&PyType_Type, 0));
     if (!heap_type) {
         pybind11_fail("make_default_metaclass(): error allocating metaclass!");
     }
@@ -291,7 +291,7 @@ inline PyTypeObject *make_default_metaclass() {
         pybind11_fail("make_default_metaclass(): failure in PyType_Ready()!");
     }
 
-    setattr((PyObject *) type, "__module__", str(PYBIND11_DUMMY_MODULE_NAME));
+    setattr(reinterpret_cast<PyObject *>(type), "__module__", str(PYBIND11_DUMMY_MODULE_NAME));
     PYBIND11_SET_OLDPY_QUALNAME(type, name_obj);
 
     return type;
@@ -306,7 +306,7 @@ inline void traverse_offset_bases(void *valueptr,
                                   instance *self,
                                   bool (*f)(void * /*parentptr*/, instance * /*self*/)) {
     for (handle h : reinterpret_borrow<tuple>(tinfo->type->tp_bases)) {
-        if (auto *parent_tinfo = get_type_info((PyTypeObject *) h.ptr())) {
+        if (auto *parent_tinfo = get_type_info(reinterpret_cast<PyTypeObject *>(h.ptr()))) {
             for (auto &c : parent_tinfo->implicit_casts) {
                 if (c.first == tinfo->cpptype) {
                     auto *parentptr = c.second(valueptr);
@@ -530,7 +530,7 @@ inline PyObject *make_object_base_type(PyTypeObject *metaclass) {
        issue no Python C API calls which could potentially invoke the
        garbage collector (the GC will call type_traverse(), which will in
        turn find the newly constructed type in an invalid state) */
-    auto *heap_type = (PyHeapTypeObject *) metaclass->tp_alloc(metaclass, 0);
+    auto *heap_type = reinterpret_cast<PyHeapTypeObject *>(metaclass->tp_alloc(metaclass, 0));
     if (!heap_type) {
         pybind11_fail("make_object_base_type(): error allocating type!");
     }
@@ -557,11 +557,11 @@ inline PyObject *make_object_base_type(PyTypeObject *metaclass) {
         pybind11_fail("PyType_Ready failed in make_object_base_type(): " + error_string());
     }
 
-    setattr((PyObject *) type, "__module__", str(PYBIND11_DUMMY_MODULE_NAME));
+    setattr(reinterpret_cast<PyObject *>(type), "__module__", str(PYBIND11_DUMMY_MODULE_NAME));
     PYBIND11_SET_OLDPY_QUALNAME(type, name_obj);
 
     assert(!PyType_HasFeature(type, Py_TPFLAGS_HAVE_GC));
-    return (PyObject *) heap_type;
+    return reinterpret_cast<PyObject *>(heap_type);
 }
 
 /// dynamic_attr: Allow the garbage collector to traverse the internal instance `__dict__`.
@@ -746,7 +746,7 @@ inline PyObject *make_new_python_type(const type_record &rec) {
         /* Allocate memory for docstring (Python will free this later on) */
         size_t size = std::strlen(rec.doc) + 1;
 #if PY_VERSION_HEX >= 0x030D0000
-        tp_doc = (char *) PyMem_MALLOC(size);
+        tp_doc = static_cast<char *>(PyMem_MALLOC(size));
 #else
         tp_doc = (char *) PyObject_MALLOC(size);
 #endif
@@ -761,10 +761,10 @@ inline PyObject *make_new_python_type(const type_record &rec) {
        issue no Python C API calls which could potentially invoke the
        garbage collector (the GC will call type_traverse(), which will in
        turn find the newly constructed type in an invalid state) */
-    auto *metaclass
-        = rec.metaclass.ptr() ? (PyTypeObject *) rec.metaclass.ptr() : internals.default_metaclass;
+    auto *metaclass = rec.metaclass.ptr() ? reinterpret_cast<PyTypeObject *>(rec.metaclass.ptr())
+                                          : internals.default_metaclass;
 
-    auto *heap_type = (PyHeapTypeObject *) metaclass->tp_alloc(metaclass, 0);
+    auto *heap_type = reinterpret_cast<PyHeapTypeObject *>(metaclass->tp_alloc(metaclass, 0));
     if (!heap_type) {
         pybind11_fail(std::string(rec.name) + ": Unable to create type object!");
     }
@@ -777,7 +777,7 @@ inline PyObject *make_new_python_type(const type_record &rec) {
     auto *type = &heap_type->ht_type;
     type->tp_name = full_name;
     type->tp_doc = tp_doc;
-    type->tp_base = type_incref((PyTypeObject *) base);
+    type->tp_base = type_incref(reinterpret_cast<PyTypeObject *>(base));
     type->tp_basicsize = static_cast<ssize_t>(sizeof(instance));
     if (!bases.empty()) {
         type->tp_bases = bases.release().ptr();
@@ -818,18 +818,18 @@ inline PyObject *make_new_python_type(const type_record &rec) {
 
     /* Register type with the parent scope */
     if (rec.scope) {
-        setattr(rec.scope, rec.name, (PyObject *) type);
+        setattr(rec.scope, rec.name, reinterpret_cast<PyObject *>(type));
     } else {
         Py_INCREF(type); // Keep it alive forever (reference leak)
     }
 
     if (module_) { // Needed by pydoc
-        setattr((PyObject *) type, "__module__", module_);
+        setattr(reinterpret_cast<PyObject *>(type), "__module__", module_);
     }
 
     PYBIND11_SET_OLDPY_QUALNAME(type, qualname);
 
-    return (PyObject *) type;
+    return reinterpret_cast<PyObject *>(type);
 }
 
 PYBIND11_NAMESPACE_END(detail)

include/pybind11/detail/cpp_conduit.h

@@ -21,13 +21,13 @@ inline bool type_is_managed_by_our_internals(PyTypeObject *type_obj) {
     return bool(internals.registered_types_py.find(type_obj)
                 != internals.registered_types_py.end());
 #else
-    return bool(type_obj->tp_new == pybind11_object_new);
+    return (type_obj->tp_new == pybind11_object_new);
 #endif
 }
 
 inline bool is_instance_method_of_type(PyTypeObject *type_obj, PyObject *attr_name) {
     PyObject *descr = _PyType_Lookup(type_obj, attr_name);
-    return bool((descr != nullptr) && PyInstanceMethod_Check(descr));
+    return ((descr != nullptr) && PyInstanceMethod_Check(descr));
 }
 
 inline object try_get_cpp_conduit_method(PyObject *obj) {

include/pybind11/detail/function_record_pyobject.h

@@ -126,7 +126,7 @@ inline bool is_function_record_PyObject(PyObject *obj) {
 
 inline function_record *function_record_ptr_from_PyObject(PyObject *obj) {
     if (is_function_record_PyObject(obj)) {
-        return ((detail::function_record_PyObject *) obj)->cpp_func_rec;
+        return (reinterpret_cast<detail::function_record_PyObject *>(obj))->cpp_func_rec;
     }
     return nullptr;
 }
@@ -137,7 +137,7 @@ inline object function_record_PyObject_New() {
         throw error_already_set();
     }
     py_func_rec->cpp_func_rec = nullptr; // For clarity/purity. Redundant in practice.
-    return reinterpret_steal<object>((PyObject *) py_func_rec);
+    return reinterpret_steal<object>(reinterpret_cast<PyObject *>(py_func_rec));
 }
 
 PYBIND11_NAMESPACE_BEGIN(function_record_PyTypeObject_methods)

include/pybind11/detail/init.h

@@ -476,9 +476,9 @@ void setstate(value_and_holder &v_h, std::pair<T, O> &&result, bool need_alias)
         return;
     }
     // Our tests never run into an unset dict, but being careful here for now (see #5658)
-    auto dict = getattr((PyObject *) v_h.inst, "__dict__", none());
+    auto dict = getattr(reinterpret_cast<PyObject *>(v_h.inst), "__dict__", none());
     if (dict.is_none()) {
-        setattr((PyObject *) v_h.inst, "__dict__", d);
+        setattr(reinterpret_cast<PyObject *>(v_h.inst), "__dict__", d);
     } else {
         // Keep the original object dict and just update it
         if (PyDict_Update(dict.ptr(), d.ptr()) < 0) {

include/pybind11/detail/internals.h

@@ -606,9 +606,8 @@ class internals_pp_manager {
             // this could be called without an active interpreter, just use what was cached
             if (!tstate || tstate->interp == last_istate_tls()) {
                 auto tpp = internals_p_tls();
-                if (tpp) {
-                    delete tpp;
-                }
+
+                delete tpp;
             }
             unref();
             return;

include/pybind11/detail/type_caster_base.h

@@ -125,7 +125,7 @@ PYBIND11_NOINLINE void all_type_info_populate(PyTypeObject *t, std::vector<type_
     assert(bases.empty());
     std::vector<PyTypeObject *> check;
     for (handle parent : reinterpret_borrow<tuple>(t->tp_bases)) {
-        check.push_back((PyTypeObject *) parent.ptr());
+        check.push_back(reinterpret_cast<PyTypeObject *>(parent.ptr()));
     }
     auto const &type_dict = get_internals().registered_types_py;
     for (size_t i = 0; i < check.size(); i++) {
@@ -168,7 +168,7 @@ PYBIND11_NOINLINE void all_type_info_populate(PyTypeObject *t, std::vector<type_
                 i--;
             }
             for (handle parent : reinterpret_borrow<tuple>(type->tp_bases)) {
-                check.push_back((PyTypeObject *) parent.ptr());
+                check.push_back(reinterpret_cast<PyTypeObject *>(parent.ptr()));
             }
         }
     }
@@ -286,7 +286,7 @@ PYBIND11_NOINLINE detail::type_info *get_type_info(const std::type_info &tp,
 
 PYBIND11_NOINLINE handle get_type_handle(const std::type_info &tp, bool throw_if_missing) {
     detail::type_info *type_info = get_type_info(tp, throw_if_missing);
-    return handle(type_info ? ((PyObject *) type_info->type) : nullptr);
+    return handle(type_info ? (reinterpret_cast<PyObject *>(type_info->type)) : nullptr);
 }
 
 inline bool try_incref(PyObject *obj) {
@@ -506,7 +506,7 @@ PYBIND11_NOINLINE void instance::allocate_layout() {
         // efficient for small allocations like the one we're doing here;
         // for larger allocations they are just wrappers around malloc.
         // TODO: is this still true for pure Python 3.6?
-        nonsimple.values_and_holders = (void **) PyMem_Calloc(space, sizeof(void *));
+        nonsimple.values_and_holders = static_cast<void **>(PyMem_Calloc(space, sizeof(void *)));
         if (!nonsimple.values_and_holders) {
             throw std::bad_alloc();
         }
@@ -537,7 +537,7 @@ PYBIND11_NOINLINE handle get_object_handle(const void *ptr, const detail::type_i
         for (auto it = range.first; it != range.second; ++it) {
             for (const auto &vh : values_and_holders(it->second)) {
                 if (vh.type == type) {
-                    return handle((PyObject *) it->second);
+                    return handle(reinterpret_cast<PyObject *>(it->second));
                 }
             }
         }
@@ -1700,7 +1700,7 @@ inline std::string quote_cpp_type_name(const std::string &cpp_type_name) {
 
 PYBIND11_NOINLINE std::string type_info_description(const std::type_info &ti) {
     if (auto *type_data = get_type_info(ti)) {
-        handle th((PyObject *) type_data->type);
+        handle th(reinterpret_cast<PyObject *>(type_data->type));
         return th.attr("__module__").cast<std::string>() + '.'
                + th.attr("__qualname__").cast<std::string>();
     }