Class weakref

include/pybind11/pytypes.h:1983–1998

};

class weakref : public object {
public:
    PYBIND11_OBJECT_CVT_DEFAULT(weakref, object, PyWeakref_Check, raw_weakref)
    explicit weakref(handle obj, handle callback = {})
        : object(PyWeakref_NewRef(obj.ptr(), callback.ptr()), stolen_t{}) {
        if (!m_ptr) {
            if (PyErr_Occurred()) {
                throw error_already_set();
            }
            pybind11_fail("Could not allocate weak reference!");
        }
    }

private:
    static PyObject *raw_weakref(PyObject *o) { return PyWeakref_NewRef(o, nullptr); }
};

class slice : public object {
public: