2 pybind11/detail/class.h: Python C API implementation details for py::class_
4 Copyright (c) 2017 Wenzel Jakob <wenzel.jakob@epfl.ch>
6 All rights reserved. Use of this source code is governed by a
7 BSD-style license that can be found in the LICENSE file.
13 #include "../options.h"
15 NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
16 NAMESPACE_BEGIN(detail)
18 #if PY_VERSION_HEX >= 0x03030000
19 # define PYBIND11_BUILTIN_QUALNAME
20 # define PYBIND11_SET_OLDPY_QUALNAME(obj, nameobj)
22 // In pre-3.3 Python, we still set __qualname__ so that we can produce reliable function type
23 // signatures; in 3.3+ this macro expands to nothing:
24 # define PYBIND11_SET_OLDPY_QUALNAME(obj, nameobj) setattr((PyObject *) obj, "__qualname__", nameobj)
27 inline PyTypeObject *type_incref(PyTypeObject *type) {
32 #if !defined(PYPY_VERSION)
34 /// `pybind11_static_property.__get__()`: Always pass the class instead of the instance.
35 extern "C" inline PyObject *pybind11_static_get(PyObject *self, PyObject * /*ob*/, PyObject *cls) {
36 return PyProperty_Type.tp_descr_get(self, cls, cls);
39 /// `pybind11_static_property.__set__()`: Just like the above `__get__()`.
40 extern "C" inline int pybind11_static_set(PyObject *self, PyObject *obj, PyObject *value) {
41 PyObject *cls = PyType_Check(obj) ? obj : (PyObject *) Py_TYPE(obj);
42 return PyProperty_Type.tp_descr_set(self, cls, value);
45 /** A `static_property` is the same as a `property` but the `__get__()` and `__set__()`
46 methods are modified to always use the object type instead of a concrete instance.
47 Return value: New reference. */
48 inline PyTypeObject *make_static_property_type() {
49 constexpr auto *name = "pybind11_static_property";
50 auto name_obj = reinterpret_steal<object>(PYBIND11_FROM_STRING(name));
52 /* Danger zone: from now (and until PyType_Ready), make sure to
53 issue no Python C API calls which could potentially invoke the
54 garbage collector (the GC will call type_traverse(), which will in
55 turn find the newly constructed type in an invalid state) */
56 auto heap_type = (PyHeapTypeObject *) PyType_Type.tp_alloc(&PyType_Type, 0);
58 pybind11_fail("make_static_property_type(): error allocating type!");
60 heap_type->ht_name = name_obj.inc_ref().ptr();
61 #ifdef PYBIND11_BUILTIN_QUALNAME
62 heap_type->ht_qualname = name_obj.inc_ref().ptr();
65 auto type = &heap_type->ht_type;
67 type->tp_base = type_incref(&PyProperty_Type);
68 type->tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HEAPTYPE;
69 type->tp_descr_get = pybind11_static_get;
70 type->tp_descr_set = pybind11_static_set;
72 if (PyType_Ready(type) < 0)
73 pybind11_fail("make_static_property_type(): failure in PyType_Ready()!");
75 setattr((PyObject *) type, "__module__", str("pybind11_builtins"));
76 PYBIND11_SET_OLDPY_QUALNAME(type, name_obj);
83 /** PyPy has some issues with the above C API, so we evaluate Python code instead.
84 This function will only be called once so performance isn't really a concern.
85 Return value: New reference. */
86 inline PyTypeObject *make_static_property_type() {
88 PyObject *result = PyRun_String(R"(\
89 class pybind11_static_property(property):
90 def __get__(self, obj, cls):
91 return property.__get__(self, cls, cls)
93 def __set__(self, obj, value):
94 cls = obj if isinstance(obj, type) else type(obj)
95 property.__set__(self, cls, value)
96 )", Py_file_input, d.ptr(), d.ptr()
98 if (result == nullptr)
99 throw error_already_set();
101 return (PyTypeObject *) d["pybind11_static_property"].cast<object>().release().ptr();
106 /** Types with static properties need to handle `Type.static_prop = x` in a specific way.
107 By default, Python replaces the `static_property` itself, but for wrapped C++ types
108 we need to call `static_property.__set__()` in order to propagate the new value to
109 the underlying C++ data structure. */
110 extern "C" inline int pybind11_meta_setattro(PyObject* obj, PyObject* name, PyObject* value) {
111 // Use `_PyType_Lookup()` instead of `PyObject_GetAttr()` in order to get the raw
112 // descriptor (`property`) instead of calling `tp_descr_get` (`property.__get__()`).
113 PyObject *descr = _PyType_Lookup((PyTypeObject *) obj, name);
115 // The following assignment combinations are possible:
116 // 1. `Type.static_prop = value` --> descr_set: `Type.static_prop.__set__(value)`
117 // 2. `Type.static_prop = other_static_prop` --> setattro: replace existing `static_prop`
118 // 3. `Type.regular_attribute = value` --> setattro: regular attribute assignment
119 const auto static_prop = (PyObject *) get_internals().static_property_type;
120 const auto call_descr_set = descr && PyObject_IsInstance(descr, static_prop)
121 && !PyObject_IsInstance(value, static_prop);
122 if (call_descr_set) {
123 // Call `static_property.__set__()` instead of replacing the `static_property`.
124 #if !defined(PYPY_VERSION)
125 return Py_TYPE(descr)->tp_descr_set(descr, obj, value);
127 if (PyObject *result = PyObject_CallMethod(descr, "__set__", "OO", obj, value)) {
135 // Replace existing attribute.
136 return PyType_Type.tp_setattro(obj, name, value);
140 #if PY_MAJOR_VERSION >= 3
142 * Python 3's PyInstanceMethod_Type hides itself via its tp_descr_get, which prevents aliasing
143 * methods via cls.attr("m2") = cls.attr("m1"): instead the tp_descr_get returns a plain function,
144 * when called on a class, or a PyMethod, when called on an instance. Override that behaviour here
145 * to do a special case bypass for PyInstanceMethod_Types.
147 extern "C" inline PyObject *pybind11_meta_getattro(PyObject *obj, PyObject *name) {
148 PyObject *descr = _PyType_Lookup((PyTypeObject *) obj, name);
149 if (descr && PyInstanceMethod_Check(descr)) {
154 return PyType_Type.tp_getattro(obj, name);
159 /** This metaclass is assigned by default to all pybind11 types and is required in order
160 for static properties to function correctly. Users may override this using `py::metaclass`.
161 Return value: New reference. */
162 inline PyTypeObject* make_default_metaclass() {
163 constexpr auto *name = "pybind11_type";
164 auto name_obj = reinterpret_steal<object>(PYBIND11_FROM_STRING(name));
166 /* Danger zone: from now (and until PyType_Ready), make sure to
167 issue no Python C API calls which could potentially invoke the
168 garbage collector (the GC will call type_traverse(), which will in
169 turn find the newly constructed type in an invalid state) */
170 auto heap_type = (PyHeapTypeObject *) PyType_Type.tp_alloc(&PyType_Type, 0);
172 pybind11_fail("make_default_metaclass(): error allocating metaclass!");
174 heap_type->ht_name = name_obj.inc_ref().ptr();
175 #ifdef PYBIND11_BUILTIN_QUALNAME
176 heap_type->ht_qualname = name_obj.inc_ref().ptr();
179 auto type = &heap_type->ht_type;
180 type->tp_name = name;
181 type->tp_base = type_incref(&PyType_Type);
182 type->tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HEAPTYPE;
184 type->tp_setattro = pybind11_meta_setattro;
185 #if PY_MAJOR_VERSION >= 3
186 type->tp_getattro = pybind11_meta_getattro;
189 if (PyType_Ready(type) < 0)
190 pybind11_fail("make_default_metaclass(): failure in PyType_Ready()!");
192 setattr((PyObject *) type, "__module__", str("pybind11_builtins"));
193 PYBIND11_SET_OLDPY_QUALNAME(type, name_obj);
198 /// For multiple inheritance types we need to recursively register/deregister base pointers for any
199 /// base classes with pointers that are difference from the instance value pointer so that we can
200 /// correctly recognize an offset base class pointer. This calls a function with any offset base ptrs.
201 inline void traverse_offset_bases(void *valueptr, const detail::type_info *tinfo, instance *self,
202 bool (*f)(void * /*parentptr*/, instance * /*self*/)) {
203 for (handle h : reinterpret_borrow<tuple>(tinfo->type->tp_bases)) {
204 if (auto parent_tinfo = get_type_info((PyTypeObject *) h.ptr())) {
205 for (auto &c : parent_tinfo->implicit_casts) {
206 if (c.first == tinfo->cpptype) {
207 auto *parentptr = c.second(valueptr);
208 if (parentptr != valueptr)
210 traverse_offset_bases(parentptr, parent_tinfo, self, f);
218 inline bool register_instance_impl(void *ptr, instance *self) {
219 get_internals().registered_instances.emplace(ptr, self);
220 return true; // unused, but gives the same signature as the deregister func
222 inline bool deregister_instance_impl(void *ptr, instance *self) {
223 auto ®istered_instances = get_internals().registered_instances;
224 auto range = registered_instances.equal_range(ptr);
225 for (auto it = range.first; it != range.second; ++it) {
226 if (Py_TYPE(self) == Py_TYPE(it->second)) {
227 registered_instances.erase(it);
234 inline void register_instance(instance *self, void *valptr, const type_info *tinfo) {
235 register_instance_impl(valptr, self);
236 if (!tinfo->simple_ancestors)
237 traverse_offset_bases(valptr, tinfo, self, register_instance_impl);
240 inline bool deregister_instance(instance *self, void *valptr, const type_info *tinfo) {
241 bool ret = deregister_instance_impl(valptr, self);
242 if (!tinfo->simple_ancestors)
243 traverse_offset_bases(valptr, tinfo, self, deregister_instance_impl);
247 /// Instance creation function for all pybind11 types. It allocates the internal instance layout for
248 /// holding C++ objects and holders. Allocation is done lazily (the first time the instance is cast
249 /// to a reference or pointer), and initialization is done by an `__init__` function.
250 inline PyObject *make_new_instance(PyTypeObject *type) {
251 #if defined(PYPY_VERSION)
252 // PyPy gets tp_basicsize wrong (issue 2482) under multiple inheritance when the first inherited
253 // object is a a plain Python type (i.e. not derived from an extension type). Fix it.
254 ssize_t instance_size = static_cast<ssize_t>(sizeof(instance));
255 if (type->tp_basicsize < instance_size) {
256 type->tp_basicsize = instance_size;
259 PyObject *self = type->tp_alloc(type, 0);
260 auto inst = reinterpret_cast<instance *>(self);
261 // Allocate the value/holder internals:
262 inst->allocate_layout();
269 /// Instance creation function for all pybind11 types. It only allocates space for the
270 /// C++ object, but doesn't call the constructor -- an `__init__` function must do that.
271 extern "C" inline PyObject *pybind11_object_new(PyTypeObject *type, PyObject *, PyObject *) {
272 return make_new_instance(type);
275 /// An `__init__` function constructs the C++ object. Users should provide at least one
276 /// of these using `py::init` or directly with `.def(__init__, ...)`. Otherwise, the
277 /// following default function will be used which simply throws an exception.
278 extern "C" inline int pybind11_object_init(PyObject *self, PyObject *, PyObject *) {
279 PyTypeObject *type = Py_TYPE(self);
281 #if defined(PYPY_VERSION)
282 msg += handle((PyObject *) type).attr("__module__").cast<std::string>() + ".";
284 msg += type->tp_name;
285 msg += ": No constructor defined!";
286 PyErr_SetString(PyExc_TypeError, msg.c_str());
290 inline void add_patient(PyObject *nurse, PyObject *patient) {
291 auto &internals = get_internals();
292 auto instance = reinterpret_cast<detail::instance *>(nurse);
293 instance->has_patients = true;
295 internals.patients[nurse].push_back(patient);
298 inline void clear_patients(PyObject *self) {
299 auto instance = reinterpret_cast<detail::instance *>(self);
300 auto &internals = get_internals();
301 auto pos = internals.patients.find(self);
302 assert(pos != internals.patients.end());
303 // Clearing the patients can cause more Python code to run, which
304 // can invalidate the iterator. Extract the vector of patients
305 // from the unordered_map first.
306 auto patients = std::move(pos->second);
307 internals.patients.erase(pos);
308 instance->has_patients = false;
309 for (PyObject *&patient : patients)
313 /// Clears all internal data from the instance and removes it from registered instances in
314 /// preparation for deallocation.
315 inline void clear_instance(PyObject *self) {
316 auto instance = reinterpret_cast<detail::instance *>(self);
318 // Deallocate any values/holders, if present:
319 for (auto &v_h : values_and_holders(instance)) {
322 // We have to deregister before we call dealloc because, for virtual MI types, we still
323 // need to be able to get the parent pointers.
324 if (v_h.instance_registered() && !deregister_instance(instance, v_h.value_ptr(), v_h.type))
325 pybind11_fail("pybind11_object_dealloc(): Tried to deallocate unregistered instance!");
327 if (instance->owned || v_h.holder_constructed())
328 v_h.type->dealloc(v_h);
331 // Deallocate the value/holder layout internals:
332 instance->deallocate_layout();
334 if (instance->weakrefs)
335 PyObject_ClearWeakRefs(self);
337 PyObject **dict_ptr = _PyObject_GetDictPtr(self);
341 if (instance->has_patients)
342 clear_patients(self);
345 /// Instance destructor function for all pybind11 types. It calls `type_info.dealloc`
346 /// to destroy the C++ object itself, while the rest is Python bookkeeping.
347 extern "C" inline void pybind11_object_dealloc(PyObject *self) {
348 clear_instance(self);
350 auto type = Py_TYPE(self);
353 #if PY_VERSION_HEX < 0x03080000
354 // `type->tp_dealloc != pybind11_object_dealloc` means that we're being called
355 // as part of a derived type's dealloc, in which case we're not allowed to decref
356 // the type here. For cross-module compatibility, we shouldn't compare directly
357 // with `pybind11_object_dealloc`, but with the common one stashed in internals.
358 auto pybind11_object_type = (PyTypeObject *) get_internals().instance_base;
359 if (type->tp_dealloc == pybind11_object_type->tp_dealloc)
362 // This was not needed before Python 3.8 (Python issue 35810)
363 // https://github.com/pybind/pybind11/issues/1946
368 /** Create the type which can be used as a common base for all classes. This is
369 needed in order to satisfy Python's requirements for multiple inheritance.
370 Return value: New reference. */
371 inline PyObject *make_object_base_type(PyTypeObject *metaclass) {
372 constexpr auto *name = "pybind11_object";
373 auto name_obj = reinterpret_steal<object>(PYBIND11_FROM_STRING(name));
375 /* Danger zone: from now (and until PyType_Ready), make sure to
376 issue no Python C API calls which could potentially invoke the
377 garbage collector (the GC will call type_traverse(), which will in
378 turn find the newly constructed type in an invalid state) */
379 auto heap_type = (PyHeapTypeObject *) metaclass->tp_alloc(metaclass, 0);
381 pybind11_fail("make_object_base_type(): error allocating type!");
383 heap_type->ht_name = name_obj.inc_ref().ptr();
384 #ifdef PYBIND11_BUILTIN_QUALNAME
385 heap_type->ht_qualname = name_obj.inc_ref().ptr();
388 auto type = &heap_type->ht_type;
389 type->tp_name = name;
390 type->tp_base = type_incref(&PyBaseObject_Type);
391 type->tp_basicsize = static_cast<ssize_t>(sizeof(instance));
392 type->tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HEAPTYPE;
394 type->tp_new = pybind11_object_new;
395 type->tp_init = pybind11_object_init;
396 type->tp_dealloc = pybind11_object_dealloc;
398 /* Support weak references (needed for the keep_alive feature) */
399 type->tp_weaklistoffset = offsetof(instance, weakrefs);
401 if (PyType_Ready(type) < 0)
402 pybind11_fail("PyType_Ready failed in make_object_base_type():" + error_string());
404 setattr((PyObject *) type, "__module__", str("pybind11_builtins"));
405 PYBIND11_SET_OLDPY_QUALNAME(type, name_obj);
407 assert(!PyType_HasFeature(type, Py_TPFLAGS_HAVE_GC));
408 return (PyObject *) heap_type;
411 /// dynamic_attr: Support for `d = instance.__dict__`.
412 extern "C" inline PyObject *pybind11_get_dict(PyObject *self, void *) {
413 PyObject *&dict = *_PyObject_GetDictPtr(self);
420 /// dynamic_attr: Support for `instance.__dict__ = dict()`.
421 extern "C" inline int pybind11_set_dict(PyObject *self, PyObject *new_dict, void *) {
422 if (!PyDict_Check(new_dict)) {
423 PyErr_Format(PyExc_TypeError, "__dict__ must be set to a dictionary, not a '%.200s'",
424 Py_TYPE(new_dict)->tp_name);
427 PyObject *&dict = *_PyObject_GetDictPtr(self);
434 /// dynamic_attr: Allow the garbage collector to traverse the internal instance `__dict__`.
435 extern "C" inline int pybind11_traverse(PyObject *self, visitproc visit, void *arg) {
436 PyObject *&dict = *_PyObject_GetDictPtr(self);
441 /// dynamic_attr: Allow the GC to clear the dictionary.
442 extern "C" inline int pybind11_clear(PyObject *self) {
443 PyObject *&dict = *_PyObject_GetDictPtr(self);
448 /// Give instances of this type a `__dict__` and opt into garbage collection.
449 inline void enable_dynamic_attributes(PyHeapTypeObject *heap_type) {
450 auto type = &heap_type->ht_type;
451 #if defined(PYPY_VERSION)
452 pybind11_fail(std::string(type->tp_name) + ": dynamic attributes are "
453 "currently not supported in "
454 "conjunction with PyPy!");
456 type->tp_flags |= Py_TPFLAGS_HAVE_GC;
457 type->tp_dictoffset = type->tp_basicsize; // place dict at the end
458 type->tp_basicsize += (ssize_t)sizeof(PyObject *); // and allocate enough space for it
459 type->tp_traverse = pybind11_traverse;
460 type->tp_clear = pybind11_clear;
462 static PyGetSetDef getset[] = {
463 {const_cast<char*>("__dict__"), pybind11_get_dict, pybind11_set_dict, nullptr, nullptr},
464 {nullptr, nullptr, nullptr, nullptr, nullptr}
466 type->tp_getset = getset;
469 /// buffer_protocol: Fill in the view as specified by flags.
470 extern "C" inline int pybind11_getbuffer(PyObject *obj, Py_buffer *view, int flags) {
471 // Look for a `get_buffer` implementation in this type's info or any bases (following MRO).
472 type_info *tinfo = nullptr;
473 for (auto type : reinterpret_borrow<tuple>(Py_TYPE(obj)->tp_mro)) {
474 tinfo = get_type_info((PyTypeObject *) type.ptr());
475 if (tinfo && tinfo->get_buffer)
478 if (view == nullptr || !tinfo || !tinfo->get_buffer) {
481 PyErr_SetString(PyExc_BufferError, "pybind11_getbuffer(): Internal error");
484 std::memset(view, 0, sizeof(Py_buffer));
485 buffer_info *info = tinfo->get_buffer(obj, tinfo->get_buffer_data);
488 view->internal = info;
489 view->buf = info->ptr;
490 view->itemsize = info->itemsize;
491 view->len = view->itemsize;
492 for (auto s : info->shape)
494 view->readonly = info->readonly;
495 if ((flags & PyBUF_WRITABLE) == PyBUF_WRITABLE && info->readonly) {
498 PyErr_SetString(PyExc_BufferError, "Writable buffer requested for readonly storage");
501 if ((flags & PyBUF_FORMAT) == PyBUF_FORMAT)
502 view->format = const_cast<char *>(info->format.c_str());
503 if ((flags & PyBUF_STRIDES) == PyBUF_STRIDES) {
504 view->ndim = (int) info->ndim;
505 view->strides = &info->strides[0];
506 view->shape = &info->shape[0];
508 Py_INCREF(view->obj);
512 /// buffer_protocol: Release the resources of the buffer.
513 extern "C" inline void pybind11_releasebuffer(PyObject *, Py_buffer *view) {
514 delete (buffer_info *) view->internal;
517 /// Give this type a buffer interface.
518 inline void enable_buffer_protocol(PyHeapTypeObject *heap_type) {
519 heap_type->ht_type.tp_as_buffer = &heap_type->as_buffer;
520 #if PY_MAJOR_VERSION < 3
521 heap_type->ht_type.tp_flags |= Py_TPFLAGS_HAVE_NEWBUFFER;
524 heap_type->as_buffer.bf_getbuffer = pybind11_getbuffer;
525 heap_type->as_buffer.bf_releasebuffer = pybind11_releasebuffer;
528 /** Create a brand new Python type according to the `type_record` specification.
529 Return value: New reference. */
530 inline PyObject* make_new_python_type(const type_record &rec) {
531 auto name = reinterpret_steal<object>(PYBIND11_FROM_STRING(rec.name));
533 auto qualname = name;
534 if (rec.scope && !PyModule_Check(rec.scope.ptr()) && hasattr(rec.scope, "__qualname__")) {
535 #if PY_MAJOR_VERSION >= 3
536 qualname = reinterpret_steal<object>(
537 PyUnicode_FromFormat("%U.%U", rec.scope.attr("__qualname__").ptr(), name.ptr()));
539 qualname = str(rec.scope.attr("__qualname__").cast<std::string>() + "." + rec.name);
545 if (hasattr(rec.scope, "__module__"))
546 module = rec.scope.attr("__module__");
547 else if (hasattr(rec.scope, "__name__"))
548 module = rec.scope.attr("__name__");
551 auto full_name = c_str(
552 #if !defined(PYPY_VERSION)
553 module ? str(module).cast<std::string>() + "." + rec.name :
557 char *tp_doc = nullptr;
558 if (rec.doc && options::show_user_defined_docstrings()) {
559 /* Allocate memory for docstring (using PyObject_MALLOC, since
560 Python will free this later on) */
561 size_t size = strlen(rec.doc) + 1;
562 tp_doc = (char *) PyObject_MALLOC(size);
563 memcpy((void *) tp_doc, rec.doc, size);
566 auto &internals = get_internals();
567 auto bases = tuple(rec.bases);
568 auto base = (bases.size() == 0) ? internals.instance_base
571 /* Danger zone: from now (and until PyType_Ready), make sure to
572 issue no Python C API calls which could potentially invoke the
573 garbage collector (the GC will call type_traverse(), which will in
574 turn find the newly constructed type in an invalid state) */
575 auto metaclass = rec.metaclass.ptr() ? (PyTypeObject *) rec.metaclass.ptr()
576 : internals.default_metaclass;
578 auto heap_type = (PyHeapTypeObject *) metaclass->tp_alloc(metaclass, 0);
580 pybind11_fail(std::string(rec.name) + ": Unable to create type object!");
582 heap_type->ht_name = name.release().ptr();
583 #ifdef PYBIND11_BUILTIN_QUALNAME
584 heap_type->ht_qualname = qualname.inc_ref().ptr();
587 auto type = &heap_type->ht_type;
588 type->tp_name = full_name;
589 type->tp_doc = tp_doc;
590 type->tp_base = type_incref((PyTypeObject *)base);
591 type->tp_basicsize = static_cast<ssize_t>(sizeof(instance));
592 if (bases.size() > 0)
593 type->tp_bases = bases.release().ptr();
595 /* Don't inherit base __init__ */
596 type->tp_init = pybind11_object_init;
598 /* Supported protocols */
599 type->tp_as_number = &heap_type->as_number;
600 type->tp_as_sequence = &heap_type->as_sequence;
601 type->tp_as_mapping = &heap_type->as_mapping;
602 #if PY_VERSION_HEX >= 0x03050000
603 type->tp_as_async = &heap_type->as_async;
607 type->tp_flags |= Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HEAPTYPE;
608 #if PY_MAJOR_VERSION < 3
609 type->tp_flags |= Py_TPFLAGS_CHECKTYPES;
612 if (rec.dynamic_attr)
613 enable_dynamic_attributes(heap_type);
615 if (rec.buffer_protocol)
616 enable_buffer_protocol(heap_type);
618 if (PyType_Ready(type) < 0)
619 pybind11_fail(std::string(rec.name) + ": PyType_Ready failed (" + error_string() + ")!");
621 assert(rec.dynamic_attr ? PyType_HasFeature(type, Py_TPFLAGS_HAVE_GC)
622 : !PyType_HasFeature(type, Py_TPFLAGS_HAVE_GC));
624 /* Register type with the parent scope */
626 setattr(rec.scope, rec.name, (PyObject *) type);
628 Py_INCREF(type); // Keep it alive forever (reference leak)
630 if (module) // Needed by pydoc
631 setattr((PyObject *) type, "__module__", module);
633 PYBIND11_SET_OLDPY_QUALNAME(type, qualname);
635 return (PyObject *) type;
638 NAMESPACE_END(detail)
639 NAMESPACE_END(PYBIND11_NAMESPACE)