Add py::pickle() adaptor for safer __getstate__/__setstate__ bindings
This is analogous to `py::init()` vs `__init__` + placement-new.
`py::pickle()` reuses most of the implementation details of `py::init()`.
diff --git a/tests/test_pickling.cpp b/tests/test_pickling.cpp
index 1e5f4ce..821462a 100644
--- a/tests/test_pickling.cpp
+++ b/tests/test_pickling.cpp
@@ -25,6 +25,12 @@
int m_extra1 = 0;
int m_extra2 = 0;
};
+
+ class PickleableNew : public Pickleable {
+ public:
+ using Pickleable::Pickleable;
+ };
+
py::class_<Pickleable>(m, "Pickleable")
.def(py::init<std::string>())
.def("value", &Pickleable::value)
@@ -49,6 +55,23 @@
p.setExtra2(t[2].cast<int>());
});
+ py::class_<PickleableNew, Pickleable>(m, "PickleableNew")
+ .def(py::init<std::string>())
+ .def(py::pickle(
+ [](const PickleableNew &p) {
+ return py::make_tuple(p.value(), p.extra1(), p.extra2());
+ },
+ [](py::tuple t) {
+ if (t.size() != 3)
+ throw std::runtime_error("Invalid state!");
+ auto p = PickleableNew(t[0].cast<std::string>());
+
+ p.setExtra1(t[1].cast<int>());
+ p.setExtra2(t[2].cast<int>());
+ return p;
+ }
+ ));
+
#if !defined(PYPY_VERSION)
// test_roundtrip_with_dict
class PickleableWithDict {
@@ -58,6 +81,12 @@
std::string value;
int extra;
};
+
+ class PickleableWithDictNew : public PickleableWithDict {
+ public:
+ using PickleableWithDict::PickleableWithDict;
+ };
+
py::class_<PickleableWithDict>(m, "PickleableWithDict", py::dynamic_attr())
.def(py::init<std::string>())
.def_readwrite("value", &PickleableWithDict::value)
@@ -79,5 +108,23 @@
/* Assign Python state */
self.attr("__dict__") = t[2];
});
+
+ py::class_<PickleableWithDictNew, PickleableWithDict>(m, "PickleableWithDictNew")
+ .def(py::init<std::string>())
+ .def(py::pickle(
+ [](py::object self) {
+ return py::make_tuple(self.attr("value"), self.attr("extra"), self.attr("__dict__"));
+ },
+ [](py::tuple t) {
+ if (t.size() != 3)
+ throw std::runtime_error("Invalid state!");
+
+ auto cpp_state = PickleableWithDictNew(t[0].cast<std::string>());
+ cpp_state.extra = t[1].cast<int>();
+
+ auto py_state = t[2].cast<py::dict>();
+ return std::make_pair(cpp_state, py_state);
+ }
+ ));
#endif
}