Skip to content

Enable defining custom __new__ #3265

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 8 commits into from
Sep 20, 2021
Merged

Enable defining custom __new__ #3265

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
8 commits
Select commit Hold shift + click to select a range
6dfa12c
Enable defining custom __new__
Skylion007 Sep 11, 2021
79ad9c0
See if xfail needed
Skylion007 Sep 11, 2021
417b894
Qualify auto self
Skylion007 Sep 11, 2021
194033e
Unconditionally defining PYBIND11_DISABLE_NEW_STYLE_INIT_WARNING. Ret…
rwgk Sep 12, 2021
ed915d4
Use new style __init__
Skylion007 Sep 12, 2021
a2923bd
Simplify __new__ creation
Skylion007 Sep 16, 2021
b04ee30
Reviewer suggestions
Skylion007 Sep 17, 2021
124d136
Match indentation
Skylion007 Sep 18, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 2 additions & 1 deletion include/pybind11/pybind11.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -416,7 +416,8 @@ class cpp_function : public function {
detail::function_record *chain = nullptr, *chain_start = rec;
if (rec->sibling) {
if (PyCFunction_Check(rec->sibling.ptr())) {
auto rec_capsule = reinterpret_borrow<capsule>(PyCFunction_GET_SELF(rec->sibling.ptr()));
auto *self = PyCFunction_GET_SELF(rec->sibling.ptr());
capsule rec_capsule = isinstance<capsule>(self) ? reinterpret_borrow<capsule>(self) : capsule(self);
chain = (detail::function_record *) rec_capsule;
/* Never append a method to an overload chain of a parent class;
instead, hide the parent's overloads in this case */
Expand Down
15 changes: 15 additions & 0 deletions tests/test_class.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -47,10 +47,25 @@ TEST_SUBMODULE(class_, m) {
}
~NoConstructor() { print_destroyed(this); }
};
struct NoConstructorNew {
NoConstructorNew() = default;
NoConstructorNew(const NoConstructorNew &) = default;
NoConstructorNew(NoConstructorNew &&) = default;
static NoConstructorNew *new_instance() {
auto *ptr = new NoConstructorNew();
print_created(ptr, "via new_instance");
return ptr;
}
~NoConstructorNew() { print_destroyed(this); }
};

py::class_<NoConstructor>(m, "NoConstructor")
.def_static("new_instance", &NoConstructor::new_instance, "Return an instance");

py::class_<NoConstructorNew>(m, "NoConstructorNew")
.def(py::init([](NoConstructorNew *self) { return self; })) // Need a NOOP __init__
Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I also wish there was a cleaner way to not have to implement __init__ if new is defined, but I can't figure out how to hack to the metaclass not to complain.

Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Maybe something like .def_new(...) or .def(py::new(...)) that wraps the two methods you have right now?

.def_static("__new__", [](const py::object *) { return NoConstructorNew::new_instance(); } );

// test_inheritance
class Pet {
public:
Expand Down
8 changes: 8 additions & 0 deletions tests/test_class.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -25,6 +25,14 @@ def test_instance(msg):
assert cstats.alive() == 0


def test_instance_new(msg):
instance = m.NoConstructorNew() # .__new__(m.NoConstructor.__class__)
cstats = ConstructorStats.get(m.NoConstructorNew)
assert cstats.alive() == 1
del instance
assert cstats.alive() == 0


def test_type():
assert m.check_type(1) == m.DerivedClass1
with pytest.raises(RuntimeError) as execinfo:
Expand Down