treat Parameter the same way as Tensor

torch/csrc/autograd/init.cpp

@@ -39,6 +39,14 @@ PyObject* THPAutograd_initExtension(PyObject* _unused, PyObject *unused) {
   auto _C_m = py::handle(torch_C_module).cast<py::module>();
   auto m = _C_m.def_submodule("_autograd", "autograd bindings");
 
+  auto parameter_module = THPObjectPtr(PyImport_ImportModule("torch.nn.parameter"));
+  if (!parameter_module)
+    return nullptr;
+
+  // NOTE: "leaks" ParameterClass
+  ParameterClass = PyObject_GetAttrString(parameter_module, "Parameter");
+  if (!ParameterClass)
+    return nullptr;
 
   py::enum_<ProfilerState>(m, "ProfilerState")
       .value("Disabled", ProfilerState::Disabled)

torch/csrc/autograd/python_variable.cpp

@@ -44,6 +44,11 @@ namespace py = pybind11;
 
 PyObject *THPVariableClass = nullptr;
 
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
+PyObject *ParameterClass = nullptr;
+
+// clang-tidy gets confused by static const
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
 static const char* VOLATILE_WARNING =
     "volatile was removed and now has no effect. Use "
     "`with torch.no_grad():` instead.";

torch/csrc/autograd/python_variable.h

@@ -19,12 +19,17 @@ struct THPVariable {
 };
 
 THP_API PyObject *THPVariableClass;
+THP_API PyObject *ParameterClass;
 
 bool THPVariable_initModule(PyObject *module);
 THP_API PyObject * THPVariable_Wrap(torch::autograd::Variable var);
 
 static inline bool THPVariable_CheckExact(PyObject *obj) {
-  return Py_TYPE(obj) == (PyTypeObject*)THPVariableClass;
+  auto obj_py_type = Py_TYPE(obj);
+  return (
+    obj_py_type == (PyTypeObject*)THPVariableClass ||
+    obj_py_type == (PyTypeObject*)ParameterClass
+  );
 }
 
 inline bool THPVariable_Check(PyObject *obj)