pybind11/tests/test_call_policies.cpp

33     // Parent/Child are used in:
46     class Parent {
48         Parent() { py::print("Allocating parent."); }
49         ~Parent() { py::print("Releasing parent."); }
54     py::class_<Parent>(m, "Parent")
56         .def(py::init([](Child *) { return new Parent(); }), py::keep_alive<1, 2>())
57         .def("addChild", &Parent::addChild)
58         .def("addChildKeepAlive", &Parent::addChild, py::keep_alive<1, 2>())
59         .def("returnChild", &Parent::returnChild)
60         .def("returnChildKeepAlive", &Parent::returnChild, py::keep_alive<1, 0>())
61         .def("returnNullChildKeepAliveChild", &Parent::returnNullChild, py::keep_alive<1, 0>())
62         .def("returnNullChildKeepAliveParent", &Parent::returnNullChild, py::keep_alive<0, 1>());
66     class ParentGC : public Parent {
68         using Parent::Parent;
70     py::class_<ParentGC, Parent>(m, "ParentGC", py::dynamic_attr())