Convert the ngraph::Function from and to python capsule

python/pyngraph/function.cpp

@@ -14,6 +14,8 @@
 // limitations under the License.
 //*****************************************************************************
 
+// #include <Python.h>
+
 #include <pybind11/pybind11.h>
 #include <pybind11/stl.h>
 
@@ -49,4 +51,23 @@ void regclass_pyngraph_Function(py::module m)
             py::cast(self.get_output_shape(0)).attr("__str__")().cast<std::string>();
         return "<" + class_name + ": '" + self.get_friendly_name() + "' (" + shape + ")>";
     });
+    function.def_static("from_capsule", [](py::object* capsule) {
+        auto* pycapsule_ptr = capsule->ptr();
+        auto* ngraph_function = reinterpret_cast<std::shared_ptr<ngraph::Function>*>(PyCapsule_GetPointer(pycapsule_ptr, "ngraph_function"));
+        // std::cout << "from_capsule: " << (*fun)->get_name() << " " << (*fun)->get_friendly_name() << " " << (*fun).get() << std::endl;
+        return *ngraph_function;
+    });
+    function.def_static("to_capsule", [](std::shared_ptr<ngraph::Function>& ngraph_function) {
+        // std::cout << "to_capsule_1: " << ngraph_function->get_name() << " " << ngraph_function->get_friendly_name() << " " 
+        //           << ngraph_function.get()  << " " << ngraph_function.use_count() << std::endl;
+        auto pybind_capsule = py::capsule(&ngraph_function, "ngraph_function", nullptr);
+
+        auto* ptr = pybind_capsule.ptr();
+        auto* fun = reinterpret_cast<std::shared_ptr<ngraph::Function>*>(PyCapsule_GetPointer(ptr, "ngraph_function"));
+
+        // std::cout << "to_capsule_2: " << (*fun)->get_name() << " " << (*fun)->get_friendly_name() << " " << (*fun).get()  
+        //           << " " << fun->use_count() << std::endl;
+
+        return pybind_capsule;
+    });
 }