Converting test_unique_ptr_member to using classh: fully working, ASAN, MSAN, UBSAN clean.

tests/test_unique_ptr_member.cpp

 #include "pybind11_tests.h"
 
-#include <pybind11/vptr_holder.h>
+#include <pybind11/classh.h>
 
-#include <iostream>
 #include <memory>
 
 namespace pybind11_tests {
 namespace unique_ptr_member {
 
-inline void to_cout(std::string text) { std::cout << text << std::endl; }
-
 class pointee { // NOT copyable.
-  public:
+public:
     pointee() = default;
 
-    int get_int() const {
-        to_cout("pointee::get_int()");
-        //TRIGGER_SEGSEV
-        return 213;
-    }
-
-    ~pointee() { to_cout("~pointee()"); }
+    int get_int() const { return 213; }
 
-  private:
+private:
     pointee(const pointee &) = delete;
-    pointee(pointee &&) = delete;
+    pointee(pointee &&)      = delete;
     pointee &operator=(const pointee &) = delete;
     pointee &operator=(pointee &&) = delete;
 };
@@ -34,88 +25,36 @@ inline std::unique_ptr<pointee> make_unique_pointee() {
 }
 
 class ptr_owner {
-  public:
+public:
     explicit ptr_owner(std::unique_ptr<pointee> ptr) : ptr_(std::move(ptr)) {}
 
     bool is_owner() const { return bool(ptr_); }
 
-    std::unique_ptr<pointee> give_up_ownership_via_unique_ptr() {
-        return std::move(ptr_);
-    }
-    std::shared_ptr<pointee> give_up_ownership_via_shared_ptr() {
-        return std::move(ptr_);
-    }
+    std::unique_ptr<pointee> give_up_ownership_via_unique_ptr() { return std::move(ptr_); }
+    std::shared_ptr<pointee> give_up_ownership_via_shared_ptr() { return std::move(ptr_); }
 
-  private:
+private:
     std::unique_ptr<pointee> ptr_;
 };
 
-// Just to have a minimal example of a typical C++ pattern.
-inline int cpp_pattern() {
-    auto obj = make_unique_pointee();
-    int result = (obj ? 1 : 8);
-    obj->get_int();
-    ptr_owner owner(std::move(obj));
-    result = result * 10 + (obj ? 8 : 1);
-    result = result * 10 + (owner.is_owner() ? 1 : 8);
-    to_cout("before give up");
-    auto reclaimed = owner.give_up_ownership_via_shared_ptr();
-    to_cout("after give up");
-    result = result * 10 + (owner.is_owner() ? 8 : 1);
-    result = result * 10 + (reclaimed ? 1 : 8);
-    reclaimed.reset();
-    to_cout("after del");
-    result = result * 10 + (reclaimed ? 8 : 1);
-    return result;
-}
-
 } // namespace unique_ptr_member
 } // namespace pybind11_tests
 
-namespace pybind11 {
-namespace detail {
-template <>
-struct type_caster<
-    std::unique_ptr<pybind11_tests::unique_ptr_member::pointee>> {
-  public:
-    PYBIND11_TYPE_CASTER(
-        std::unique_ptr<pybind11_tests::unique_ptr_member::pointee>,
-        _("std::unique_ptr<pybind11_tests::unique_ptr_member::pointee>"));
-
-    bool load(handle /* src */, bool) {
-        throw std::runtime_error("Not implemented: load");
-    }
-
-    static handle
-    cast(std::unique_ptr<pybind11_tests::unique_ptr_member::pointee> /* src */,
-         return_value_policy /* policy */, handle /* parent */) {
-        throw std::runtime_error("Not implemented: cast");
-    }
-};
-} // namespace detail
-} // namespace pybind11
+PYBIND11_CLASSH_TYPE_CASTERS(pybind11_tests::unique_ptr_member::pointee)
 
 namespace pybind11_tests {
 namespace unique_ptr_member {
 
 TEST_SUBMODULE(unique_ptr_member, m) {
-    m.def("to_cout", to_cout);
-
-    py::class_<pointee, py::vptr_holder<pointee>>(m, "pointee")
-        .def(py::init<>())
-        .def("get_int", &pointee::get_int);
+    py::classh<pointee>(m, "pointee").def(py::init<>()).def("get_int", &pointee::get_int);
 
     m.def("make_unique_pointee", make_unique_pointee);
 
     py::class_<ptr_owner>(m, "ptr_owner")
         .def(py::init<std::unique_ptr<pointee>>(), py::arg("ptr"))
         .def("is_owner", &ptr_owner::is_owner)
-        .def("give_up_ownership_via_unique_ptr",
-             &ptr_owner::give_up_ownership_via_unique_ptr)
-        .def("give_up_ownership_via_shared_ptr",
-             &ptr_owner::give_up_ownership_via_shared_ptr);
-
-    m.def("cpp_pattern", cpp_pattern);
+        .def("give_up_ownership_via_unique_ptr", &ptr_owner::give_up_ownership_via_unique_ptr)
+        .def("give_up_ownership_via_shared_ptr", &ptr_owner::give_up_ownership_via_shared_ptr);
 }
 
 } // namespace unique_ptr_member

tests/test_unique_ptr_member.py

@@ -5,34 +5,25 @@ from pybind11_tests import unique_ptr_member as m
 
 
 def test_make_unique_pointee():
-    m.to_cout("")
     obj = m.make_unique_pointee()
     assert obj.get_int() == 213
-    m.to_cout("")
 
 
-def test_pointee_and_ptr_owner():
-    m.to_cout("")
+@pytest.mark.parametrize(
+    "give_up_ownership_via",
+    ["give_up_ownership_via_unique_ptr", "give_up_ownership_via_shared_ptr"],
+)
+def test_pointee_and_ptr_owner(give_up_ownership_via):
     obj = m.pointee()
     assert obj.get_int() == 213
     owner = m.ptr_owner(obj)
     with pytest.raises(RuntimeError) as exc_info:
         obj.get_int()
-    assert str(exc_info.value) == "Invalid object instance"
+    assert (
+        str(exc_info.value)
+        == "Missing value for wrapped C++ type: Python instance is uninitialized or was disowned."
+    )
     assert owner.is_owner()
-    m.to_cout("before give up")
-    reclaimed = owner.give_up_ownership_via_shared_ptr()
-    m.to_cout("after give up")
+    reclaimed = getattr(owner, give_up_ownership_via)()
     assert not owner.is_owner()
-    # assert reclaimed.get_int() == 213
-    del reclaimed
-    m.to_cout("after del")
-    m.to_cout("3")
-    m.to_cout("")
-
-
-def test_cpp_pattern():
-    m.to_cout("")
-    res = m.cpp_pattern()
-    assert res == 111111
-    m.to_cout("")
+    assert reclaimed.get_int() == 213